Bsi bs en 01870 4 2012

Verification: By checking the relevant drawings and/or circuit diagrams, inspection of the machine, measurement and relevant functional testing on the machine.. Verification: By checkin

General

For the purposes of this document, the terms and definitions given in EN ISO 12100:2010 and the following apply.

Definitions

The multi-blade rip sawing machine is engineered for use with saw blades positioned on fixed spindles during cutting It features an integrated power feed system, such as rollers or chain conveyors, for workpiece feeding, along with manual loading and unloading capabilities The saw blades can be mounted on one or more vertically adjustable spindles, allowing for axial adjustments relative to the spindle or in conjunction with it The arrangement of the saw blade spindles can vary, being positioned entirely above, entirely below, or both above and below the workpiece support.

The cutting mode can be ‘against the feed’ or ‘climb cutting’ or a combination of both (see Figure 1) a) Cutting against the feed b) Climb cutting

Figure 1 — Relation between cutting direction and feed direction

3.2.2 machine actuator power mechanism used to effect motion of the machine

The integrated feed mechanism is designed to hold and control the workpiece or tool mechanically during machining operations, ensuring precise and efficient processing within the machine.

Machines referenced in this document utilize integrated feed systems, which can include rollers, chain conveyors, or chain beds The terms in brackets do not apply to these machines.

3.2.4 stationary machine machine designed to be located on or fixed to the floor or other parts of the structure of the premises and to be stationary during use

3.2.5 loading the machine manual or automatic placing of the workpiece onto a carriage, magazine, lift, hopper, moveable bed, conveyor or the presentation of the workpiece to an integrated feed device

3.2.6 ejection unexpected movement of the workpiece or parts of it, or part of the machine from the machine during processing

Kickback refers to a specific type of ejection that occurs when a workpiece or its components, as well as parts of the machine, move unexpectedly in the opposite direction of the feed during processing.

Note 1 to entry The words in brackets are not applicable to the machine covered by this document

3.2.8 anti-kickback fingers moveable elements at the infeed or the outfeed of the machine to prevent kickback of the workpiece or divided parts of it

3.2.9 anti-splinter fingers moveable elements at the infeed of the machine to prevent the ejection of splinters

3.2.10 run-up time time elapsed from the actuation of the start control device until the spindle speed reaches the intended speed

3.2.11 run-down time time elapsed from the actuation of the stop control device up to spindle standstill

3.2.12 cutting width capacity maximum distance between external cutting surfaces of the two outside saw blades mounted at extreme positions on the saw spindle

Note 1 to entry See Figure 2, f

The maximum distance between the outer cutting planes of the outside saw blades is crucial for optimal performance Additionally, the distance from the inner surface of the outside saw blade to the lateral limitation set by the feed system plays a significant role The width of the workpiece conveyor must also be considered, along with the maximum distance between the saw blade and the fence Furthermore, the cutting width of the saw blade and the cutting width capacity, defined as the distance between the inner cutting planes of the outside saw blades, are essential factors for effective cutting operations.

Manual loading of power-fed machines involves the operator directly presenting the workpiece to the machine's integrated feed system, such as rotating feed rollers, chain conveyors, or chain beds In this process, there is no intermediate loading device to facilitate the transfer of the workpiece from the operator to the integrated feed.

Manual unloading of power-fed machines involves the operator directly removing the workpiece from the machine's outfeed This process does not utilize any intermediate unloading device to facilitate the transfer of the workpiece to the operator.

Supplier information includes statements, sales literature, leaflets, or other documents in which the manufacturer or supplier declares the characteristics or compliance of the material or product with relevant standards.

3.2.16 safety programmable logic controller (PLC) programmable logic controller dedicated to safety related application designed in the required PL according to

3.2.17 safety related part of the control system (SRP/CS) part of a control system that responds to safety-related input signals and generate safety-related output signals (EN ISO 13849-1:2008, 3.1.1)

Safety-related embedded software (SRESW) refers to firmware and system software provided by the control manufacturer that is integral to the system This software is not user-modifiable, ensuring compliance with standards such as EN ISO 13849-1:2008, section 3.1.37.

Note 1 to entry Embedded software is usually written in full variability language (FVL) defined in 3.1.35 of

Note 2 to entry For example the operating system of a speed monitoring device

Safety-related application software (SRASW) is specialized software developed by machine manufacturers It includes logic sequences, limits, and expressions that manage the necessary inputs, outputs, calculations, and decisions to comply with safety requirements outlined in SRP/CS (EN ISO 13849-1:2008, 3.1.36).

3.2.20 performance level PL discrete level used to specify the ability of safety-related parts of control systems to perform a safety function under foreseeable conditions (EN ISO 13849-1:2008, 3.1.23)

This clause outlines the major hazards and hazardous situations identified through risk assessment, as specified in EN ISO 12100:2010, that are pertinent to the machines within the defined scope and necessitate action to mitigate risks The document addresses these significant hazards by establishing safety requirements and measures or by referencing applicable standards.

These hazards are listed in Tables 1

Table 1 — List of significant hazards

Hazards, hazardous situations and hazardous events

Relevant sub- clause of this document

- machine parts or workpieces: a) shape; 6.2.2.1, 6.2.2.2, 6.3 5.3.2, 5.3.3,

5.2.10, 5.3.5, 5.3.7, 5.4.5 c) mass and stability (potential energy of elements which may move under the effect of gravity)

5.2.7 d) mass and velocity (kinetic energy of elements in controlled or uncontrolled motion);

- accumulation of energy inside the machinery: f) liquids and gases under pressure; 6.2.10, 6.3.5.4 5.3.5.2, 5.4.7,

1.5 Drawing-in or trapping hazard 5.3.6, 5.3.7

1.9 High pressure fluid injection or ejection hazard

2.1 Contact of persons with live parts (direct contact) 6.2.9, 6.3.5.4 5.4.4

2.2 Contact of persons with parts which have become live under faulty conditions

4 Hazards generated by noise, resulting in:

4.1 Hearing loss (deafness), other physiological disorders (loss of balance, loss of awareness)

4.2 Interference with speech communication, acoustic signals

7 Hazards generated by materials and substances (and their constituent elements) processed or used by the machinery

7.1 Hazards from contact with or inhalation of harmful fluids and dusts 6.2.3, 6.2.4 5.4.3, 6.3

8 Hazards generated by neglecting ergonomic principles in machinery design related to:

8.1 Unhealthy postures or excessive effort 6.2.7, 6.2.8, 6.2.11.12,

8.2 Hand-arm or foot-leg anatomy 6.2.8 5.2.2, 5.4.5

8.5 Mental overload and underload, stress 6.2.8 6.3

8.7 Design, location or identification of manual controls 6.2.8.f, 6.2.11.8 5.2.2, 5.4.5

8.8 Design or location of visual display units 6.2.8, 6.4.2 5.2.2, 5.4.5

10 Unexpected start up, unexpected overrun/overspeed (or any similar malfunction) from:

10.1 Failure/disorder of the control system 6.2.11, 6.3.5.4 5.2.1, 5.2.11,

10.2 Restoration of energy supply after an interruption 6.2.11.4 5.2.10, 5.4.6,

10.3 External influences on electrical equipment 6.2.11.11 5.2.1, 5.4.8

10.6 Errors made by the operator (due to mismatch of machinery with human characteristics and abilities, see 8.6)

11 Impossibility of stopping the machine in the best possible conditions 6.2.11.1, 6.2.11.3,

12 Variations in the rotational speed of tools 6.2.2.2, 6.2.3 5.2.9

13 Failure of the power supply 6.2.11.1, 6.2.11.4 5.2.10

14 Failure of the control circuit 6.2.11, 6.3.5.4 5.2.11

17 Falling or ejected objects or fluids 6.2.3, 6.2.10 5.3.5, Annex D

18 Loss of stability / overturning of machinery 6.3.2.6 5.3.1

5 Safety requirements and/or measures

General

The machine shall comply with the safety requirements and/or protective measures of Clause 5

The machine must be designed in accordance with EN ISO 12100:2010 principles to address relevant but not significant hazards, such as sharp edges on the machine frame, which are not covered in this document.

NOTE 2 For guidance in connection with risk reduction by design, see 6.2 of EN ISO 12100:2010, and for safeguarding measures, see 6.3 of EN ISO 12100:2010.

Controls

Safety and reliability of control systems

Safety-related parts of a control system (SRP/CS) begin with the initiation of safety-related input signals, such as the actuating cam and position switch roller, and conclude at the output of power control elements, including the main contacts of a contactor To effectively implement any safety-related function, it is essential to adhere to the relevant requirements.

Safety-related parts of the control system of the machine are those concerning the functions listed in Table 2

The design of the safety-related control system shall be such as to achieve the machine safety functions required in this document

NOTE If monitoring systems are used for diagnostics, they are also considered as SRP/CS

For safety-related parts of the control system (SRP/CS) outlined in column 1 of Table 2, the minimum performance level must comply with the specifications in column 2 of Table 2, as per EN ISO 13849-1:2008, section 4.5.

Table 2 — Safety functions, Performance Levels (PL)

The Function Performance Level (PL) is outlined in various clauses of this document Key aspects include the prevention of unexpected start-up (c 5.2.10, 5.2.11, 5.3.6), normal stopping procedures (c 5.2.4), and emergency stop protocols (c 5.2.5) Additionally, the interlocking of guards for drives is specified in clause c 5.3.7.3, while the interlocking of guards for tools with guard locking is detailed in clauses c 5.3.7.1, 5.3.7.2, and 5.3.7.3 Finally, the interlocking of functions is addressed in clauses c 5.2.4, 5.2.7, 5.2.8, and 5.3.4.

5.3.5.1, 5.3.6, 5.3.7 feed speed indication/detection = c 5.2.9 zero speed detection = c 5.3.7.1 in setting mode: initiation of powered saw blades axial adjustment for positioning the saw blades, feed roller height and pressure board/shoes

= c 5.2.7 mode selection = c 5.2.6, 5.3.6 hold-to-run control = c 5.2.7, 5.2.8 mechanical operated trip device = c 5.3.7.2 braking system = b or = c 5.3.4 empty machine detection = c 5.2.7, 5.3.5.1.2, 5.3.7.1 workpiece clamping = c 5.2.6, 5.2.7, 5.3.6

NOTE The average probability of a dangerous failure per hour for the different performance levels is described in

When using the same Safety-Related Parts of Control Systems (SRP/CS) across machines with various operational modes, it is essential that the SRP/CS complies with the highest Performance Level (PL) required among those modes for all safety functions.

Where a combination of SRP/CS is used the overall PL identified according 6.3 of EN ISO 13849-1:2008 shall comply at least with the PL required in Table 2

SRP/CS for which a special standard exists shall fulfil all requirements of this document

Verification: By checking the relevant drawings and/or circuit diagrams and inspection of the machine

5.2.1.1.3 Fault detection and fault reaction for safety-related parts of the control system (SRP/CS)

Unless otherwise specified in the relevant clause of this document, fault detection and fault reaction functions shall be in accordance with the requirements in 6.2.4 to 6.2.7 of EN ISO 13849-1:2008

For all components exposed to environmental conditions, e.g dust and/or gases, these conditions shall be taken into account

Safety-related electronic parts of the control system (SRP/CS) must meet environmental requirements outlined in sections 6.1 and 6.2, unless they are components governed by a specific standard.

SRP/CS must meet the EMC requirements for type 2 unless they are specifically designed to achieve performance levels b) or c) as part of a component with an existing special standard.

According to EN 61496-1:2004 and its amendment EN 61496-1:2004/A1:2008, unless Safety-Related Parts of Control Systems (SRP/CS) are specifically designed to achieve performance levels d) or e) and are part of a component governed by a special standard, they must comply with the electromagnetic compatibility (EMC) requirements for type 4 as outlined in these standards.

NOTE 1 See also 5.4.8 for the EMC requirements on the complete machine

Verification: By checking the relevant drawings and/or circuit diagrams, inspection of the machine, measurement and relevant functional testing on the machine

NOTE 2 For the components characteristics a confirmation from the components' manufacturers can be useful

Protective devices must comply with specific standards The following requirements apply to the listed devices: magnetic and proximity switches must meet the criteria outlined in section 6.2.

The EN 1088:1995+A2:2008 standard and its associated control system must achieve a performance level (PL) of c, as specified by EN ISO 13849-1:2008 Additionally, if a time delay is implemented, it must utilize a fail-safe technique, such as a capacity type, that complies with the PL = c requirements outlined in EN ISO 13849-1:2008.

NOTE 1 Also see 5.4.8 for the EMC requirements on the complete machine

Verification: By checking the relevant drawings and/or circuit diagrams, inspection of the machine, measurement and relevant functional testing of the machine

NOTE 2 For the components characteristics a confirmation from the components' manufacturers can be useful.

Position of controls

Hand-operated controls for starting and stopping the motor(s) of the saw spindle(s), as well as for adjusting the feed and height of the upper roller support, should be located as depicted in Figure 3 or on a movable control panel positioned at the loading area.

When mounted on a movable control panel attached to the machine, the front face should not be more than 700 mm from the table's front edge, and the upper surface must be positioned no higher than 1,800 mm from the floor level.

For positioning of emergency stop control see 5.2.5

Verification: By checking the relevant drawings measurement and inspection of the machine

1 position of the operator at infeed left side

Figure 3  Position of controls (front and side views of infeed) 

Starting

Before operating the machine, ensure that all interlocked guards are properly in place and functional, as outlined in section 5.3.7 For non-interlocked guards, refer to section 6.3 e) for tool spindle and guide adjustments The machine can only be started or restarted by using the designated start control device.

The safety related part of the control circuits (also see 5.2.1) for starting and the interlocking arrangements as indicated in 5.2.6, 5.2.7, 5.3.6, 5.3.7 shall be PL = c in accordance with the requirements of

For electrically operated machines the requirements of 9.2.5.2 of EN 60204-1:2006 shall apply but the exceptions described in 9.2.5.2 of EN 60204-1:2006 are not relevant

The start of the feed motor shall be possible only where the saw spindle motors are running at intended speed (e.g by a time delay conforming to 5.2.1.2 b))

When utilizing a time delay device, it is essential that the time delay is at least equal to the maximum run-up time The time delay can either be fixed or, if adjustable, the adjustment mechanism must be sealed.

Verification: By checking the relevant drawings and/or circuit diagrams, inspection of the machine and relevant functional testing of the machine.

Normal stopping

The machine will be equipped with a stop control that allows for a safe and complete halt This stopping mechanism will also ensure disconnection from the energy supply, unless it complies with the Safe Torque Off (STO) standards.

EN 61800-5-2:2007 is used and shall actuate the brake (if provided)

NOTE For normal stopping of PDS(SR) (power drive system, safety related) see 4.2.2.2 "safe torque off (STO)” and 4.2.2.3 “safe stop 1 (SS1)” of EN 61800-5-2:2007 apply

If the machine is fitted with a spring operated mechanical brake, this stop control shall be of category 0 according to 9.2.2 of EN 60204-1:2006

If the machine is fitted with any other type of brake e.g an electrical brake, this stop control shall be of category 1 according to 9.2.2 of EN 60204-1:2006

According to section 9.2.2 of EN 60204-1:2006, when a category 1 stop is implemented, the stopping sequence must first involve cutting power to all machine actuators and engaging the brake, followed by cutting power to the brake once the braking sequence is fully completed.

The control circuit design must ensure compliance with the normal stopping sequence If a time delay device is implemented, it should have a duration that is at least equal to the maximum run-down time and adhere to section 5.2.1.2 b) Additionally, the time delay must either be fixed or equipped with a sealed adjustment device.

Where separate saw spindle stop controls are provided these shall, when operated, also stop the integrated feed

The safety related part of the control circuits (also see 5.2.1) for normal stopping shall be PL = c in accordance with the requirements of EN ISO 13849-1:2008

Emergency stop

The requirements of EN ISO 13850:2008 apply and in addition:

Emergency stop controls must be installed at both the infeed and outfeed ends of machines that require manual unloading These controls should be positioned no more than 600 mm from the opening edges and from any operator-defined position specified by the machine's manufacturer Additionally, if a movable control panel is provided, emergency stop controls should also be located on it.

The emergency stop control device shall be at any time of self latching type

NOTE For emergency stop of PDS(SR) see 4.2.2.2 "safe torque off (STO)” and 4.2.2.3 “safe stop 1 (SS1)” of

Dimensions in millimetres a) View from infeed end b) View from outfeed end

1 left infeed/oufeed opening edge

2 right infeed/oufeed opening edge

Figure 4  Position of emergency stop controls 

If the machine is fitted with a spring operated mechanical brake this stop control shall be of category 0 in accordance with the requirements of 9.2.2 of EN 60204-1:2006

If a machine is equipped with a different type of brake, such as an electrical brake, the stop control must comply with category 1 as specified in section 9.2.2 of EN 60204-1:2006 When a category 1 stop control is installed, the stopping sequence must follow the guidelines outlined in section 5.2.4.

The safety related part of the control circuits (also see 5.2.1) for the emergency stop shall be PL = c in accordance with the requirements of EN ISO 13849-1:2008

Verification: By checking relevant drawings and/or circuit diagrams, inspection of the machine and relevant functional testing of the machine.

Mode selection

Mode selection control device(s) shall be lockable in each position e.g.: a) by a key-operated switch; or b) via limited access to related numerically controlled functions by means of a password

Mode selection control device(s) shall be provided:

1) For pressure shoe/board cutting mode selection on machines: i) Where the anti-kickback fingers are mounted on a shaft which rises and falls with the support for the upper feed rollers and vertical adjustment in the direction of increasing the workpiece thickness is necessary for pressure devices cutting (see Figure 5); ii) without any integrated timber detection device

2) For cleaning mode selection, if any;

3) For powered adjustments of the saw blade(s) when the guards are open

Figure 5  Example of pressure devices

5.2.6.2 Pressure shoe/board cutting mode

In pressure shoe/board cutting mode, the mode selection must adhere to specific requirements in addition to section 5.2.6.1 These include ensuring that the control system can override the interlocking of the saw blade's rotation with the upward movement of the workpiece thickness support for the upper feed rollers Furthermore, the feed must not be operational, the guard must remain closed, all machine drives must be halted, a deliberate restart of the drive motors is required, and vertical movement of the saw blade must be restricted.

The safety related part of the control circuits (also see 5.2.1) for pressure shoe/board cutting mode selection shall be PL = c in accordance with the requirements of EN ISO 13849-1:2008

When selecting the cleaning mode, it is essential to adhere to specific requirements: a) ensure that the saw blade(s) are stopped and cannot restart; b) the feed must operate solely under hold-to-run control; c) the feed movement speed must not exceed 10 m/min; d) maintain a minimum distance of 80 mm between the feed chain and fixed machine parts to mitigate crushing and shearing hazards; e) the vertical movement of the saw blade(s), pressure shoe, or board should be either manually operated or, if powered, controlled under hold-to-run with a speed adjustment not exceeding the specified limit.

10 mm s -1 and the dangerous points visible from the position of the operator when using the hold-to-run control device; f) the guards may be opened

The safety aspect of the control circuits for cleaning mode selection and hold-to-run control must meet PL = c standards as specified by EN ISO 13849-1:2008.

Verification: By checking relevant drawings and/or circuit diagrams, inspection of the machine and relevant functional testing on the machine.

Powered adjustments

5.2.7.1 Powered axial adjustment of the saw blade(s) and any other powered adjustment when guards are open

When selecting the mode for powered axial adjustment of saw blades and other powered adjustments with open guards, it is essential to adhere to specific requirements These include utilizing a hold-to-run control, ensuring the adjustment speed does not exceed 10 mm/s, making dangerous points visible from the operator's position while using the control device, and ensuring that the safety-related part of the control circuits for the hold-to-run mechanism meets the performance level PL = c as per EN ISO 13849-1:2008 standards.

Verification: By checking relevant drawings and/or circuit diagrams, inspection of the machine and relevant functional testing on the machine

5.2.7.2 Powered adjustment of the saw blade(s) when guards are closed

When powered axial adjustment of the saw blade(s) is enabled with the guards closed, it is essential to implement a detection system to ensure that timber entering the machine's infeed has successfully passed the saw blade(s) This can be achieved through monitoring the position of powered rollers in conjunction with time delay devices.

The safety related part of the control circuits (also see 5.2.1) for the machine empty detection device shall be

PL = c in accordance with the requirements of EN ISO 13849-1:2008

To ensure safety in machines with vertically powered saw spindle adjustments, it is essential to prevent contact between the saw blades of different spindles and between the saw blades and machine components This can be achieved through the use of a manually adjustable mechanical restraint device.

Verification: By checking relevant drawings and/or circuit diagrams, inspection of the machine and relevant functional testing on the machine.

Integrated feed

For start and stop of feed movements see 5.2.3 and 5.2.4

On machines with spindles cutting against the feed, reverse feed must be controlled by a hold-to-run mechanism This reverse feed is only permitted when the saw blade(s) are stationary and the anti-kickback devices are repositioned from their normal operating state.

The safety related part of the control circuits (also see 5.2.1) for the hold-to-run control shall be PL = c in accordance with the requirements of EN ISO 13849-1:2008

Verification: By checking relevant drawings and/or circuit diagrams, inspection of the machine and relevant functional testing of the machine.

Feed speed control

Machines fitted with a variable speed integrated feed shall be fitted with a feed speed indication/detection system visible from the adjusting position

The safety related part of the control circuits (also see 5.2.1) for the feed speed indication/detection system shall be PL = c in accordance with the requirements of EN ISO 13849-1:2008

Verification: By checking the relevant drawings and/or circuit diagrams, inspection of the machine and relevant functional testing on the machine.

Failure of the power supply

The requirements of Clause 6 of EN 1037:1995+A1:2008 apply and in addition:

Automatic restarts of electrically driven machines after a supply voltage restoration following an interruption must be prevented, as mandated by the requirements outlined in paragraphs 1 and 3 of section 7.5.

In case of a loss of pneumatic or hydraulic pressure, it is essential to maintain pressure on the workpiece until the saw blades come to a complete stop To ensure this requirement is met, non-return valves should be installed directly on the actuating cylinders.

Failure of the control circuits

The requirements of Clause 6 of EN 1037:1995+A1:2008 shall apply and in addition:

Control circuits must be designed to ensure that any circuit break, such as a broken wire or ruptured pipe, does not compromise safety functions This includes preventing involuntary machine starts, saw blade unclamping, or loss of workpiece clamping, in compliance with EN 60204-1:2006 and EN ISO 4413:2010 standards.

Protection against mechanical hazards

Stability

It shall be possible to fix stationary machines to a suitable stable horizontal structure e.g floor Facilities for fixing are e.g fixing holes in the machine frame (also see 6.3)

Verification: By checking relevant drawings and inspection of the machine.

Risk of break up during operation

Guards must be made from one or more materials that meet specific criteria, including: a) steel with a minimum ultimate tensile strength of 350 N/mm² and a wall thickness of at least 2 mm; b) light alloy that complies with the specifications outlined in Table 3.

Table 3— Light alloy guard thickness and tensile strength

Polycarbonate with a minimum thickness of 5 mm or other plastic materials that meet the criteria outlined in Annex D are acceptable Additionally, cast iron must have an ultimate tensile strength of at least 200 N/mm² and a minimum wall thickness of 5 mm.

Verification involves reviewing the relevant drawings and tensile strength measurements for plastic materials that do not meet the requirements outlined in section c) of the impact test specified in Annex D, along with inspecting the machine It is important to note that obtaining confirmation from the material manufacturer regarding the ultimate tensile strength can be beneficial.

Tool holder and tool design

Saw spindles shall be manufactured in accordance with the tolerances given in Annex A

Where it is necessary to apply a torque to a fastening element, e.g for tool changing, a device shall be provided to prevent rotation of the saw spindle

Spacers used for positioning saw blades must be made from materials such as steel, brass, bronze, or light alloy These spacers should feature parallel side surfaces with a tolerance of 0.02 mm and a minimum wall thickness of 9.5 mm.

To prevent the saw blade(s) from loosening during startup, operation, or braking, it is essential to implement precautions such as establishing a secure connection between the spindle and the saw blade(s).

Verification: By checking the relevant drawings, measurements, inspection of the machine and relevant functional testing on the machine.

Braking

An automatic brake shall be provided for all tool spindles where the un-braked run-down time exceeds:

 90 s for machines fitted with 200 kW or less for each motor; the braked run-down time shall not exceed

 120 s for machines with at least one motor over 200 kW; the braked run-down time shall not exceed

A PLr of at least c for the braking function shall be achieved

The braking torque shall not be applied directly to the saw blade itself or the saw blade flange(s)

Where a spring operated mechanical brake or any other type of brake not using electronic components is fitted the last paragraph of 9.3.4 of EN 60204-1:2006 does not apply (see 6.3 a))

For electrical braking, reverse current injection braking shall not be used

When an electrical brake with an electronic control system is installed, its control system must meet a minimum performance level (PL = b) and be designed in category 2 according to EN ISO 13849-1:2008, with the exception that the test rate requirement in section 4.5.4 is not applicable The safety-related part of the control circuit for braking should undergo periodic testing, such as monitoring the braked run-down time, with feedback obtained from either the encoder on the spindle motor or by measuring the residual current in the motor's power wires.

1) be independent from the basic control system for braking;

2) be independent from the intention of the operator;

3) be performed at least once within every 8 h of machine running

Where the test result is negative more than three times in succession, it shall not be possible to operate the machine A negative test result shall be indicated

The diagnostic coverage (DCavg) shall be ≥ 60%

NOTE 1 See Annex E of EN ISO 13849-1:2008 for DC estimation

A simple electronic brake, utilizing basic electronic components such as rectifiers, transistors, triacs, diodes, resistors, and thyristors, can be classified as PL=b and designed in category 1, as an exception to section 5.2.1 This classification is in accordance with the requirements of EN ISO 13849-1:2008, provided that the mean time to a dangerous failure (MTTFd) meets a "high" value of at least 30 years, as specified in Table 5 of the standard.

NOTE 2 Complex electronic components like e.g microprocessors or PLCs cannot be considered as well tried under the scope of EN ISO 13849-1:2008 and do therefore not fulfill the requirements of category 1

NOTE 3 For calculating the probability of occurrence of a dangerous failure for a simple electronic brake component with no fault detection (no DC) and no testing capability (category 1) the procedure described in Annex D of

EN ISO 13849-1:2008 can be used

Verification involves reviewing the relevant drawings and circuit diagrams, inspecting the machine, and conducting functional tests To determine the un-braked and braked run-down times, the applicable tests outlined in Annex B should be performed.

To enable manual rotation and adjustment of the saw blade, a control must be in place to release the spindle(s) brake This brake release should only occur once the spindle(s) have completely stopped turning, which can be ensured by implementing a time delay as specified in section 5.2.1.2 b) between the actuation of the control and the release of the brake.

The machine cannot be started until the spindle brake control has been reset, and resetting the brake control alone will not trigger the machine's start-up.

The safety related part of the control system for brake release shall be PL = c in accordance with the requirements of EN ISO 13849-1:2008

Verification: By checking the relevant drawings, inspection of the machine and relevant functional testing of the machine.

Devices to prevent the possibility or the effect of ejection

5.3.5.1 Infeed end of the machine

To prevent the risk of splinters or wooden fragments being ejected from the infeed side of the machine, it is essential to implement fixed guards and/or interlocked movable guards.

The machine shall be designed to allow splinters and wooden fragments evacuation from the machine without access to the dangerous moving parts e.g by gravity, suction or mechanical conveying system

To prevent the risk of splinters or wooden fragments, such as knots, being ejected from the infeed side of the machine, it is essential to implement fixed guards and protective devices, as outlined in sections 5.3.5.1.2.3 and 5.3.5.1.2.4, along with interlocked movable guards.

Verification: By checking the relevant drawings and inspection of the machine

5.3.5.1.2 Machines designed for cutting against the feed

On machines designed for cutting against the feed, anti-kickback fingers and anti-splinter fingers shall be fitted before the saw blade(s) in the feed direction

The anti-kickback- and anti-splinter system shall at least include the following components: a) 1 anti-kickback system according to 5.3.5.1.2.2; b) 2 rows of anti-splinter systems according to 5.3.5.1.2.3 which are from:

1) Type 1 and Type 2 (see 5.3.5.1.2.3.2, 5.3.5.1.2.3.3);or

2) Type 1 and Type3 (see 5.3.5.1.2.3.2, 5.3.5.1.2.3.4); or

3) two times Type 1 (see 5.3.5.1.2.3.2); c) on machines where at least one saw blade spindle cutting against the feed is mounted above the workpiece support, 1 row of the anti-splinter system according to 5.3.5.1.2.4

The anti-kickback- and anti-splinter system shall be located so as to avoid kickback and splinter or wooden fragments ejection (see e.g Figures 7 and 8)

1 anti-splinter finger below the table

5 additional anti-kickback fingers type 1 at the out feed side (see 5.3.5.1.2.2)

Figure 7 — Example 1 of anti-kickback and anti-splinter

1 anti-splinter finger below the table

Figure 8 — Example 2 of anti-kickback and anti-splinter system

Verification: By checking the relevant drawings and inspection of the machine.

Anti-kickback fingers must be installed to cover the entire cutting width of the machine, with at least one additional finger at each end These fingers and their mounting should ensure effective operation across the full cutting height, defined as functioning between angles of 85° and 55° from the horizontal Achieving this may require multiple rows or specific profiles of fingers, or a parallelogram mounting system.

Figure 9 — Example of anti-kickback finger

Figure 10 — Example of anti-kickback finger mounted on a parallelogram b) a mechanical stop shall be provided to prevent the anti-kickback fingers moving beyond the 85° point (see Figure 9);

The anti-splinter and anti-kickback fingers must adhere to specific dimensions and material standards, as outlined in Figure 11 The mounting shafts for these fingers should be constructed from solid steel with a minimum ultimate tensile strength of 570 N/mm² The fingers must feature lower tips with a maximum radius of 0.5 mm and a hardness of 45 ± 5 HRC When mounted on fixed shafts, one row of fingers should extend to within 1 mm of the table or workpiece feeding system For fingers mounted on adjustable shafts, vertical movement is only permissible when the saw blades are not rotating and the feed is halted, or through a detection system that monitors the position of the timber The safety control system must comply with PL = c as per EN ISO 13849-1:2008 Additionally, in the rest position at 85° from horizontal, the lower tips should be at least 5 mm below the upper feed roller's lowest point, and the clearance between the mounting axis diameter and the fingers' bore internal diameter must not exceed 0.5 mm.

The thickness of each spacer between the anti-kickback fingers must range from a minimum of 0.5 mm to a maximum of 1 mm Additionally, for anti-kickback fingers measuring 200 mm or less in length, the thickness should be between 6 mm and 10 mm.

The minimum thickness of each finger is 8 mm, with a maximum of 15 mm, and may be reduced in areas of shaft support or lifting elements The fingers must automatically return to their rest position when not in contact with the workpiece, and their sides should be flat and parallel within ± 0.5 mm If a row of anti-kickback fingers does not reach table level, all fingers in that row must be of the same length within ± 1 mm Additionally, the angle of the tips should range between 30° and 60°, and the anti-kickback fingers must be made from steel with an ultimate tensile strength of at least a specified value.

For machines with at least one spindle positioned above the workpiece support and cutting against the feed, the maximum distance (Lmax) between the spindle axis and the anti-kickback fingers must be 570 N/mm².

The machine can accommodate saw blades with a maximum diameter of less than 200 mm plus ẵ, as illustrated in Figure 13 However, if an additional row of anti-kickback fingers is installed in position 6, as shown in Figure 7, it must be within the specified distance Lmax.

Figure 13  Distance between saw blade axis and anti-kickback fingers (Lmax) p) where the fingers are mounted on a fixed shaft or shafts the following requirements apply:

1) a device shall be provided for lifting the anti-kickback fingers This device shall not be capable of being operated until the saw blade(s) spindles have stopped rotating and it shall not be possible to start the saw blade(s) spindle(s) as long as the fingers are in the raised position; or

2) the saw unit equipped with the largest saw-blades for which the machine is designed shall be capable of being lifted upwards so as to retract the unit entirely from the cutting area;

3) the safety related part of the control system for interlocking and detection shall be PL = c in accordance with the requirements of EN ISO 13849-1:2008 q) there shall be a workpiece support at the place where anti-kickback fingers operate

Saw blade standstill shall be detected by zero speed detection in PL = c in accordance with the requirements of EN ISO 13849-1:2008

NOTE For the ultimate tensile strength a confirmation from the manufacturer of the material can be useful

5.3.5.1.2.3 Anti-splinter fingers mounted above the table

Anti-splinter fingers/curtains mounted above the table shall extend at least over the full infeed opening width of the machine

The anti-splinter system shall pass the test in Annex C After the test the anti-splinter system shall work

Two rows of anti-splinter fingers will be installed above the machine's table, covering the entire infeed opening These rows must extend either below the workpiece conveyor by more than 6 mm and reach the table surface or be positioned no more than 1 mm above the conveyor and extend to the table surface beyond the conveyor.

When spikes are attached to the conveyor chain and anti-splinter fingers are positioned over the workpiece support, it is essential to measure the distance between the lower face of the anti-splinter finger and the top of the spikes.

The anti-splinter fingers and their mounting shall be in accordance with either:

1) type1 and type 2 or type 1 and type 1 in the case a) (see Figure 8); or

2) type 1 and type 3 in the case b) (see Figure 7)

Where two type 1 rows are provided, rows off-set according Figure 14 shall be fulfilled (i.e the rows shall not coincide)

NOTE For the ultimate tensile strength a confirmation from the manufacturer of the material can be useful

1 length of the anti-splinter

3 two off-set type 1 rows of anti-splinter fingers

Figure 14  Anti-splinter fingers over the table (type 1)

Anti-splinter fingers type 1 must meet specific criteria alongside the general requirements outlined in section 5.3.5.1.2.3.1 These fingers are required to be constructed from steel with a minimum ultimate tensile strength.

Workpiece supports and guides

Where machines are supplied with a pressure board or pressure shoe for holding down the workpiece between the saw blades, these shall be replaceable

When the pressure shoe or board is interrupted by the upward vertical adjustment of the upper feed rollers' support, the feed mechanism must be disabled In machines lacking a timber detection device, if the saw blades cut through the pressure shoe or board due to this adjustment, and the anti-kickback devices are also elevated, a mode selection switch must be installed in accordance with section 5.2.6.

Verification: By checking relevant drawings and/or circuit diagrams, inspection of the machine, measurement and relevant functional testing on the machine.

Prevention of access to moving parts

To ensure safety, fixed enclosing guards must prevent access to saw blades, except at infeed and outfeed openings When access is necessary, such as for changing blades, it should be through movable interlocked guards equipped with guard locking mechanisms This locking must utilize a zero speed detection device installed on each saw spindle motor.

The zero speed detection system shall be PL = c in accordance with the requirements of

Machines equipped with mechanical removal systems for chip and dust must ensure that access to the saw blade through the chip and dust outlets is restricted, in compliance with Table 4 of EN ISO 13857:2008.

Verification: By checking the drawings and/or circuit diagrams, measurements, inspection of the machine and relevant functional testing on the machine

5.3.7.2 Guarding of the feed mechanism

Access to the feed mechanism, except in loading and unloading areas, must be restricted by a fixed guard If frequent access is necessary (more than once a week), a movable guard that is interlocked with guard locking should be used, unless the run down time is less than 2 seconds.

To ensure safety when accessing drawing-in points from the feed rollers at the infeed or outfeed ends of the machine, it is essential to implement protective measures These measures can include either fixed guards that maintain a minimum distance of 550 mm from the nearest dangerous drawing-in or shearing point, or a trip device that complies with EN 1760-2:2001+A1:2009 standards and meets specific safety requirements.

1) the width of the trip device sensor shall be at least equal to the width of the infeed opening;

2) the bottom edge of the trip device sensor shall remain a maximum of 25 mm above the surface of the workpiece;

3) the tripping force shall be ≤ 50 N;

4) having regard to the gap between the trip sensor and the work-piece, the horizontal distance from the trip sensor to the trapping point, the response time of the trip device and the stopping time of the feed, the trip sensor shall be designed and positioned so that at the maximum feed speed a hand resting on the work-piece shall be prevented from being drawn into the trapping point;

5) it shall not in itself create a trapping hazard

The safety aspect of the control circuits for the interlocking function between the trip device and integrated feed must achieve a minimum Performance Level (PL) of c, in compliance with EN ISO 13849-1:2008 standards.

Verification: By checking relevant drawings and/or circuits diagrams, inspection of the machine, measurement and relevant functional testing on the machine

5.3.7.2.2 Machines fitted with chain conveyor feed

To eliminate crushing hazards at the infeed end of the conveyor chain, it is essential to address the risks posed by the closing links An effective solution is illustrated in Figure 20.

Where accessible, the space between the exposed edges of the chain conveyor and fixed parts of the machine shall not exceed 8 mm

The design of the machine frame at the outfeed end, where the chain conveyor re-enters, must effectively eliminate crushing or drawing-in hazards.

Verification: By checking relevant drawings, measurement, inspection of the machine and relevant functional testing on the machine

Figure 20  Risk prevention of crushing by closing links on conveyor chain

Access to all drive mechanisms shall be prevented by fixed guard(s) or moveable interlocked guard(s) with guard locking except where the run-down time is less than 2 s

A fixed guard must be equipped with a secure fixing system, such as un-losable screws, to ensure it can be safely removed by the user for maintenance and cleaning purposes, as outlined in section 6.3 u).

The safety related part of the control circuits (also see 5.2.1) for the interlocking function shall have at least

PL = c in accordance with the requirements of EN ISO 13849-1:2008

Verification: By checking the relevant drawings and/or circuit diagrams, inspection of the machine and relevant functional testing on the machine.

Protection against non-mechanical hazards

Fire

To minimise fire risk the requirements of 5.4.3 and 5.4.4 shall be met

Verification: By checking the relevant drawings, inspection of the machine and relevant functional testing of the machine.

Noise

5.4.2.1 Noise reduction at the design stage

When designing machinery the information and technical measures to control noise at source given in

When considering noise control measures, it is essential to reference EN ISO 11688-1:2009 and, where applicable, EN ISO 11688-2:2000 The primary contributors to noise in this context are the rotating main saw blades.

The operating conditions for noise measurement shall comply with Annexes Q or S of ISO 7960:1995

Mounting and operating conditions of the machine shall be identical for the determination of emission sound pressure levels at the work station and sound power levels

For machines not covered by Annex Q or Annex S of ISO 7960:1995, such as those with varying spindle speeds and saw blade diameters, the test report must include the specific operating conditions utilized.

The emission sound power levels of multi-blade rip saws must be measured using the enveloping surface measuring method outlined in EN ISO 3746:2010, with specific modifications These include ensuring the environmental indicator K 2A is 4 dB or lower, maintaining a minimum difference of 6 dB between the background sound pressure level and the machine sound pressure level at each measurement point, and applying the correction formula from section 8.3.3, formula (12) of EN ISO 3746:2010 Additionally, only the parallelepiped measurement surface should be utilized at a distance of 1 m from the reference surface, and if the distance from the machine to an auxiliary unit is less than 2 m, the auxiliary unit must be included in the reference surface The accuracy of the testing method should exceed 3 dB, and a total of nine microphone positions must be used as specified in Annex Q or Annex S of ISO 7960:1995.

Alternatively, where the facilities exist and the measurement method applies to the machine type, emission sound power levels may also be measured in accordance with a method with higher precision i.e

EN ISO 3743-1:2010, EN ISO 3743-2:2009, EN ISO 3744:2010 and EN ISO 3745:2009 without the preceding modifications

For determination of sound power level by sound intensity method, use EN ISO 9614-1:2009 (subject to agreement between the supplier and the purchaser)

Emission sound pressure levels at the workstation shall be measured in accordance with EN ISO 11202:2010 with the following modifications:

1) environmental indicator K 2A and local environmental factor K 3A shall be equal to or less than 4 dB;

2) difference between the background emission sound pressure level and the workstation sound pressure level shall be equal to or greater than 6 dB; cf EN ISO 11202:2010, 6.4.1, accuracy grade 2 (Engineering);

3) correction of the local environmental factor K 3A shall be calculated in accordance with A.2 of

EN ISO 11204:2010 with reference restricted to EN ISO 3746:2010 instead of the method given in Annex A of EN ISO 11202:2010 or in accordance with EN ISO 3743-1:2010, EN ISO 3743-2:2009,

EN ISO 3744:2010 or EN ISO 3745:2009 where one of these standards has been used as the measuring method

For noise declaration 6.3 o) shall be met.

Emission of chips and dust

The machine must be equipped with outlets for the efficient extraction of chips and dust, allowing it to connect to a dedicated chip and dust collection system.

An additional chip, splinters, wooden parts and dust mechanical removal system may be provided

It shall be impossible to reach the saw blades and moveable parts through any dust extraction outlet when the exhaust system is not connected

For optimal performance, the opening of the capture device should ideally be directed towards the projection If this alignment is not possible, it is essential to effectively direct the flow of chips and dust towards the device's opening.

The opening of the capture device shall be large enough to capture the chips and dust projected

NOTE 1 The size of the opening of the capture device depends on the emission pattern and the distance between the emission source and the opening of the capture device

The capture device must be engineered to reduce pressure drop and prevent material accumulation by avoiding sudden changes in the direction of extracted chips and dust, as well as eliminating sharp angles and obstacles that could lead to the trapping of debris.

To ensure optimal performance, the transfer of chips and dust from the capture device to the CADES (chip and dust extraction system) must adhere to specific requirements This is particularly important for flexible connections in moving units, as it helps minimize pressure drop and prevents material buildup.

To effectively transport chips and dust from the source to the collection system, the design of hoods, ducts, and baffles must be optimized for the air conveying velocity within the duct.

20 m s -1 for dry chips and 28 m s -1 for wet chips (18 %, or above, moisture content)

The pressure drop between the inlet of the capture device and the connection to the CADES shall be maximum 1 500 Pa (for the nominal air flow rate)

Verification: By checking of drawings, visual inspection and the following procedure:

 Measure the pressure drop at the chosen air flow rate by measurement under the condition given for noise measurement in the relevant C-standard or ISO 7960

To measure noise levels according to the relevant C-standard or ISO 7960, operate the machine without processing a workpiece while ensuring the CADES is disconnected Verify the machine's airflow from the capture device inlets to the CADES connection outlets by using smoke at the connection outlets.

NOTE 2 For measurement of chip and dust extraction system performance two standardised methods can be used:

Electricity

The requirements of EN 60204-1:2006 with the exception of 6.3 apply unless stated otherwise in this document

See 6.2 of EN 60204-1:2006 for the prevention of electric shock due to direct contact and Clause 7 of

EN 60204-1:2006 for protection against short circuits and overloading

NOTE 1 The protection of people against electrical shock due to indirect contacts should be normally ensured by automatic isolation of the electrical power supply of the machine by the operation of a protective device installed by the user in the line powering the machine (see the information provided by the manufacturer in the instruction handbook (see 6.3 t))

The degree of protection for electrical components out of the enclosure and the enclosure for electrical components shall be at least IP 54 in accordance with EN 60529:1991 and EN 60529:1991/A1:2000

The requirements outlined in EN 60204-1:2006 must be met, specifically: Clause 7 for equipment protection, Clause 8 for equipotential bonding, Clause 12 for conductors and cables, Clause 13 for wiring practices, and Clause 14 for electrical motors and related equipment.

Electrical enclosures must be safeguarded against the ejection of tools and workpieces, ensuring that live parts remain inaccessible as per section 6.2.2 of EN 60204-1:2006 Additionally, the risk of fire is mitigated when power circuits are protected against overcurrent, in accordance with section 7.2.2 of the same standard.

In accordance with test 1 in 18.2 and 18.6 of EN 60204-1:2006 the test for the continuity of the protective bonding circuit and functional tests apply

Verification: By checking the relevant drawings and/or circuit diagrams, inspection of the machine and relevant tests (specified in test 1 of 18.2 and 18.6 of EN 60204-1:2006)

NOTE 2 For electrical components characteristics the information from the electrical component supplier can be useful.

Ergonomics and handling

The requirements of EN 614-1:2006+A1:2009 shall apply and in addition:

The machine and its controls shall be designed according to ergonomic principles in accordance with

EN 1005-4:2005+A1:2008 for work posture which is not fatiguing

The positioning, marking and illumination (if necessary) of control devices, and facilities for materials and tool set handling shall be in accordance with ergonomic principles in accordance with EN 894-1:1997+A1:2008,

Tanks containing compressed air drainers and oilers shall be placed or oriented in such a way that the filler and drain pipes can be easily reached

Machine components weighing over 25 kg must be equipped with appropriate attachments for lifting devices, such as lugs, strategically placed to prevent overturning, falling, or uncontrolled movement during transport, assembly, disassembly, disabling, and scrapping.

The height of the machine table above floor level shall be ≥ 750 mm and ≤ 1100 mm

If the machine is fitted with a movable control panel, this panel shall be fitted with a facility to move it in the desired position

NOTE Further guidance is given in EN 60204-1:2006, EN 614-1:2006+A1: 2009 and EN 614-2:2000+A1: 2008 Also see 5.2.2 for position of controls, 6.3, EN 894-3:2000+A1:2008 and EN 1005-3:2002+A1:2008

Verification: By checking the relevant drawings, inspection of the machine, measurement and relevant functional testing of the machine.

Pneumatics

For machines fitted with pneumatic equipment the requirements of EN ISO 4414:2010 shall apply (see also 5.4.13)

Verification: By checking the relevant drawings, and inspection of machine.

Hydraulics

For machines fitted with hydraulic equipment the requirements of EN ISO 4413:2010 shall apply

Verification: By checking the relevant drawings, and inspection of machine.

Electromagnetic compatibility

The machine shall have sufficient immunity to electromagnetic disturbances to enable it to operate correctly in accordance with EN 60439-1:1999 and EN 60439-1:1999/A1:2004, EN 50370-1:2005 and EN 50370-2:2003

Machines that use CE-marked electrical components, when installed according to the manufacturers' guidelines, are typically safeguarded against external electromagnetic interference.

Verification: By checking the relevant drawings and/or circuit diagrams and inspection of the machine.

Laser

If the machine is fitted with a laser to indicate the cutting line, the laser shall be of category 2, 2M or a lower risk category in accordance with the requirements of EN 60825-1:2007

The laser shall be fitted to the machine so that warnings on the laser itself remain visible

All guidelines from the laser manufacturer regarding installation and usage must be adhered to The laser's operating instructions should be clearly outlined in the instruction manual Additionally, warning labels and recommendations for eye protection, if applicable, should be prominently displayed on the machine near the operator's area.

Verification: By checking the relevant drawings and inspection of the machine

NOTE For the laser characteristics the information from the manufacturer of the laser can be useful.

Static electricity

If the machine is fitted with flexible hoses for chip and dust extraction, the hoses shall be able to lead charge to earth potential

Errors of fitting

The machine shall be designed so that it is not possible to mount saw blades with dimensions larger than those for which it has been designed Also see 5.4.12, 5.4.13, 6.2 and 6.3

Maintenance

10.2 Restoration of energy supply after an interruption 6.2.11.4 5.2.10, 5.4.6,

10.3 External influences on electrical equipment 6.2.11.11 5.2.1, 5.4.8

10.6 Errors made by the operator (due to mismatch of machinery with human characteristics and abilities, see 8.6)

11 Impossibility of stopping the machine in the best possible conditions 6.2.11.1, 6.2.11.3,

12 Variations in the rotational speed of tools 6.2.2.2, 6.2.3 5.2.9

13 Failure of the power supply 6.2.11.1, 6.2.11.4 5.2.10

14 Failure of the control circuit 6.2.11, 6.3.5.4 5.2.11

17 Falling or ejected objects or fluids 6.2.3, 6.2.10 5.3.5, Annex D

18 Loss of stability / overturning of machinery 6.3.2.6 5.3.1

5 Safety requirements and/or measures

The machine shall comply with the safety requirements and/or protective measures of Clause 5

NOTE 1 In addition, the machine should be designed according to the principles of EN ISO 12100:2010 for hazards relevant but not significant, which are not dealt with by this document (e.g sharp edges of the machine frame)

NOTE 2 For guidance in connection with risk reduction by design, see 6.2 of EN ISO 12100:2010, and for safeguarding measures, see 6.3 of EN ISO 12100:2010

5.2.1 Safety and reliability of control systems

Safety-related parts of a control system (SRP/CS) begin with the initiation of safety-related input signals, such as the actuating cam and position switch roller, and conclude at the output of power control elements, including the main contacts of a contactor To effectively implement any safety-related function, it is essential to adhere to the relevant requirements.

Safety-related parts of the control system of the machine are those concerning the functions listed in Table 2

The design of the safety-related control system shall be such as to achieve the machine safety functions required in this document

NOTE If monitoring systems are used for diagnostics, they are also considered as SRP/CS

For safety-related parts of the control system (SRP/CS) that perform the functions specified in column 1 of Table 2, the minimum performance level must comply with the requirements outlined in column 2 of Table 2, as per EN ISO 13849-1:2008, section 4.5.

Table 2 — Safety functions, Performance Levels (PL)

The Function Performance Level (PL) is outlined in various clauses of this document Key aspects include the prevention of unexpected start-up (c 5.2.10, 5.2.11, 5.3.6), normal stopping procedures (c 5.2.4), and emergency stop protocols (c 5.2.5) Additionally, the interlocking of guards for drives is specified in clause c 5.3.7.3, while the interlocking of guards for tools with guard locking is detailed in clauses c 5.3.7.1, c 5.3.7.2, and c 5.3.7.3 Finally, the interlocking of functions is addressed in clauses c 5.2.4, c 5.2.7, c 5.2.8, and c 5.3.4.