Iec 60800 2009

The significant technical changes with respect to the previous edition are as follows: – introduction of heating cable sets; – testing of heating cable sets, including the integrated col

General

Cables must be engineered and built to ensure electrical, thermal, and mechanical durability, guaranteeing safe performance during normal use for both users and the surrounding environment.

All integral components shall comply with this standard All others shall comply with relevant product standards

Compliance is checked by all the requirements and tests specified in this standard

All parts of a heating cable intended for use in contact with potable water shall be constructed of materials that meet relevant national or local requirements

LICENSED TO MECON Limited - RANCHI/BANGALORE, FOR INTERNAL USE AT THIS LOCATION ONLY, SUPPLIED BY BOOK SUPPLY BUREAU.

Conductors

Conductors are made up of one or more wires composed of pure or alloyed metals For conductors made of pure copper with a metallic coating, it is essential that the coating is suitable for the conductor's operating temperature The resistance of these conductors is a critical factor to consider.

20 °C ± 1 °C shall be in accordance with the values given by the manufacturer with a maximum tolerance of %

The heating conductor material used shall not have a negative temperature coefficient of resistance Compliance shall be checked according to the test in 8.2.1.

Insulation

The insulating materials used in heating cables shall be suitable for the intended use This shall be verified by meeting the tests and the requirements given in this standard

The minimum average value of the insulation thickness shall be stated by the manufacturer, and measured according to IEC 60811-1-1, and meet the minimum requirement specified in

Electrically conducting screen

Heating cables must include a uniformly distributed electrically conductive metallic screen, sheath, tape, or laminate when necessary This conductive material is essential for ensuring that protection devices function correctly.

NOTE 1 For cables without an electrically conducting screen, additional national requirements may apply

The resistance of the conductive sheath or screen, along with a separate earthing conductor in contact with it, must not exceed the resistance of each conductor within the cable or that of a plain copper conductor.

According to IEC 60228, a class 1 conductor must have a cross-sectional area of 0.5 mm² or less The total resistance of any earthing conductor associated with this screen or sheath must not exceed that of a 0.5 mm² copper conductor To meet these specifications, multiple copper wires may be utilized.

NOTE 2 In some countries, national regulations require the resistance to be less than that of 0,5 mm 2 copper conductors

Compliance shall be checked as described in 8.2.1

If conductive sheath or screen alone is used as the earthing conductor, the resistance measured shall be the total resistance including the earthing connections delivered with the cable

Electrically conductive screens must be designed to block foreign substances larger than 1 mm in diameter from entering the insulation without making contact with the screen Compliance with this requirement will be verified through the testing method outlined in section 8.2.5.

Armouring

Armouring may include metallic or non-metallic components such as wires, sheaths, tapes, or laminates If metallic armouring is used, it must not be in direct contact with any existing metallic sheath; instead, it should be separated by a protective insulating layer that can endure mechanical stress and high temperatures during normal use, while also preventing corrosion of the metallic sheath.

Electrically conductive armouring must be designed to prevent foreign substances larger than 1 mm in diameter from penetrating the insulation without making contact with the armouring Compliance with this requirement will be verified through the testing procedure outlined in section 8.2.5.

If the armouring is based on a conductive material the same requirements as specified for the electrically conductive screen shall apply

NOTE National regulations may give other requirements.

Sheath

The sheathing materials used in heating cables shall be suitable for the intended use This shall be verified by meeting the tests and the requirements given in this standard

A non-metallic outer sheath shall give mechanical and/or corrosion protection dependent on the type of cable

The minimum average value of the sheath thickness shall be stated by the manufacturer and measured according to IEC 60811-1-1, and meet the minimum requirement specified in 8.3.5.

Moisture resistance

Heating cables shall comply with the requirements as stated in 8.2.2

NOTE This requirement is comparable with class IPX7 as defined in IEC 60529 [ 3 ]

Type tests – General requirements

For heating cables intended to be supplied in bulk, a 5 m sample of the heating cable shall be used for testing, if not otherwise specified

For factory-assembled heating cable sets that include a cold lead, splice, and end seal, it is essential to test the entire heating cable set Alternatively, a 5-meter sample of the cable can be tested Additionally, the individual components, such as the cold lead, connection splice, and end termination, can be assembled on a dummy length of cable and tested separately.

For field-assembled heating cables, the manufacturer specifies the connections and end terminations, which must be assembled according to their instructions to create a complete heating cable set This set should undergo testing, or alternatively, a 5 m sample of the cable can be tested If not specified otherwise, components like the cold lead, connection splice, and end termination may be assembled on a 5 m dummy length of cable and tested individually.

All sample components used shall be typical examples from what is supplied to the market or intended to be supplied to the market

Tests shall be conducted at a room temperature between 20 °C and 25 °C, unless otherwise specified

Unless otherwise specified, the test voltage shall be a.c at a frequency between 49 Hz and

61 Hz of approximately sinusoidal waveform

For a parallel resistive cable, the power output in Watts per metre shall be checked according to the test in 8.2.3

For a parallel resistive cable, the start-up current shall be checked according to the test in

Separate samples may be used for each test unless otherwise specified These shall be prepared in accordance with the manufacturer’s recommendations

If a sample fails to meet the specified requirements, two additional complete sets of samples must be tested Should both of these sets pass the testing criteria, the cable will be considered compliant with the test standards.

Type tests – Detailed test requirements

Electrical resistance of heating conductors and screen

The resistance of conductors and screens must be measured using appropriate methods on samples that are at least 1 meter long Two measurements should be conducted for each conductor: one at ambient temperature and another at 100 °C The ambient temperature measurement, adjusted to 20 °C ± 1 °C, will verify if the resistance values specified by the manufacturer are met for both the conductors and the screen.

The measurement at the higher temperature shall be compared with that at ambient temperature to confirm that the individual conductor(s) does not have a negative temperature coefficient of resistance.

Water immersion and temperature cycling test

A 5 m sample shall be subjected to two ageing cycles and shall be immersed for a total of

56 h in potable water at a temperature of 20 °C ± 5 °C for 8 h, 80 °C ± 5 °C for 16 h,

Samples should be transferred to preheated water containers between each sub-cycle, with the temperature in these containers controlled by placing them in preheated cabinets, in accordance with IEC 60811-1-2 standards.

Heating cable sets, including factory assembled cold lead, splice and end seal shall be subjected to this test after being assembled to a suitable heating cable

Splices and end seals intended for heating cables for field assembly shall be subjected to this test after being assembled to a suitable heating cable and with cold leads

All heating cable types and heating cable sets must be tested, except if they are clearly identified as not to be used in wet or humid conditions

The sample can be moved from the ageing water immersion unit to a different water immersion unit for dielectric testing and electrical insulation resistance testing It is essential that the water temperature in both units is maintained at 20 °C ± 5 °C.

A 5 m sample must be immersed in potable water, ensuring that the ends remain exposed to prevent flashover at the specified voltage To avoid electrical breakdown, the metallic or equivalent conductive sheath should be stripped from the ends of the sample.

Cables which have not been factory assembled and which are supplied with special connections shall be tested with these connections submerged in water

In a twin- and multi-conductor series resistive cable, where the conductors are electrically insulated from one another, voltage must be applied between the conductors as well as between the connected conductors and any metallic or equivalent conducting materials, such as the sheath, armor, or screen, and water if no armor or screen is included in the cable design.

For single conductor series heating cables featuring a metallic or similar conducting material sheath, armor, or screen, the voltage must be applied between the conductor and the sheath, armor, or screen.

Single conductor series heating cables that lack a metallic sheath, armor, or screen must be fully submerged in water, ensuring that the ends remain above the surface to prevent flashover The voltage should be applied between the conductor and the water.

For parallel resistive cables the voltage shall be applied between the conductors connected together and the metallic sheath, braid, screen or equivalent electrically conductive covering

Dielectric strength for insulated heating wires shall be tested by placing the insulated wire in potable water The voltage shall be applied between the conductor and the water

An a.c test voltage of 2 000 V shall be applied for 5 min The test voltage shall be increased gradually and the prescribed value reached in a time of 2 s to 10 s

The electrical insulation resistance shall be measured on the test sample(s) prepared in accordance with 8.2.2.1, after the dielectric test in 8.2.2.2 has been carried out

Non-screened cables shall be tested, submerged in water, with any layer(s) outside the insulation removed

For single conductor series resistive cables, it is essential to measure the resistance of the electrical insulation between the conductor and any metallic or equivalent conducting materials, including the sheath, armor, or conductive screen.

In a multi-conductor series resistive cable with electrically insulated conductors, the insulation resistance must be assessed between the connected conductors and the metallic sheath or conductive screen Additionally, measurements should be taken between each individual conductor and the remaining conductors that are connected together.

For parallel cables the resistance shall be measured between the conductors connected together and the metallic sheath, braid, screen or equivalent electrically conductive covering

Insulation resistance must be assessed using a direct current voltage of 1,000 V, with measurements taken one minute after the voltage is applied, ensuring the positive pole is connected to the water The minimum acceptable measured value is 50 MΩ.

Verification of rated output for parallel heating cables

The rated output shall be verified by the method described in IEC 62395-1 [4]

Verification of start-up current for parallel heating cables

The start-up current of the heating cable shall be measured as described in IEC 62395-1 [4].

Penetration test for electrical conductive screen

A 1 mm diameter steel test pin must be inserted through the conductive screen into the insulation, both when the cable is straight and when it is wound onto a mandrel with a diameter five times that of the cable or its minor axis.

Three samples shall be tested

It shall not be possible to push the test pin into the insulation, touching a live conductor, without touching the screen This shall be verified by activating a residual current device

The Residual Current Device (RCD) operates with a maximum sensitivity of 30 mA Testing should be performed at the rated voltage, ensuring that the test pin is not connected to earth while the RCD is linked between the branch supply and the sample, in accordance with the manufacturer's instructions.

NOTE Electrically insulated and earth connected tools should be used when voltage is applied to the sample.

Flammability test

Heating cables designed for installation within concrete, mortar, or other non-combustible materials are exempt from testing requirements However, this exemption does not extend to cold leads in heating cable sets, which must be flame retardant.

A flammability test shall be performed on heating cables and cold leads with the test apparatus described in IEC 60332-1-1 and the procedure and requirements described in

IEC 60332-1-2 The requirement for charring extending downwards does not apply when the end seal forms the lower part of the sample

The test shall be performed on the heating cable and all integral components of a heating cable set

For products containing splice and end seal components, it is essential to prepare samples that allow for separate testing of each component and the cables The middle section of the splice or end seal should be included in the cable sample where the test flame is applied, while the heating cable and/or cold lead should constitute the upper part of the sample.

2).When the end seal is tested the sample may be supported by a 0,5 mm to 1,0 mm diameter steel wire with a weight necessary to keep the sample in a stable position

Figure 1 – Typical arrangement for testing the splice

Figure 2 – Typical arrangement for testing the end seal

Deformation test for installation classification

Heating cables must endure the mechanical forces encountered during both installation and operation They are categorized into two classes: mechanical class M1, which adheres to specific compression requirements outlined in section 8.2.7.2, and mechanical class M2, as specified in section 8.2.7.3.

The test is applicable to integral components, including connection splices, end seals, and cold leads, whether they are factory mounted or designed for field assembly, along with the accessories specified by the manufacturer.

Connection point for steel wire

8.2.7.2 Class M1: cables intended for installation with low risk of mechanical damage

Three samples of completed cable, each measuring at least 200 mm in length, must be individually positioned at a temperature of 20 °C ± 5 °C They should be placed on top of a cylindrical steel rod with a diameter of 6 mm, which is supported by a flat steel base, and oriented at right angles to the rod.

A force of 600 N must be applied steadily at any intersection point of the test piece and the steel rod using a rigid plate measuring 100 mm by 100 mm Following a 30-second application of this force, the test piece should endure a voltage of 1,500 V a.c for an additional 30 seconds without failure This voltage is to be applied between the conductor(s) and the metallic screen, braid, or sheath In cases where the cable lacks a screen, the voltage will be applied between the conductor(s) and the steel rod For cables with multiple conductors, the voltage test must also be conducted between the phase conductors.

There shall be no cracks in the outer layer visible by visual inspection

None of the screen wires or conductors shall be broken as seen by visual inspection after cutting out the sheath and insulation

8.2.7.3 Class M2: cables intended for installation with higher risk of mechanical damage

Three samples of completed cable, each measuring at least 200 mm in length, must be individually positioned at a temperature of 20 °C ± 5 °C They should be placed on top of a cylindrical steel rod with a diameter of 6 mm, which is supported by a flat steel base, ensuring the samples are oriented at right angles to the rod.

A force of 1,500 N must be applied steadily at any intersection point of the test piece and the steel rod using a rigid plate measuring 100 mm by 100 mm Following a 30-second application of this force, the test piece should endure a voltage of 1,500 V a.c for an additional 30 seconds without failure This voltage is to be applied between the conductor(s) and the metallic or equivalent material, such as a screen, braid, or sheath In cases where the cable lacks a screen, the voltage should be applied between the conductor(s) and the steel rod For cables with multiple conductors, the voltage test must also be conducted between the phase conductors.

There shall be no cracks in the outer layer visible by visual inspection

None of the screen wires or conductors shall be broken as seen by visual inspection after cutting out the sheath and insulation.

Cold impact test

This test is to be carried out at –5 °C, or the lowest installation temperature specified by the manufacturer, whichever is lower

The test shall be carried out on three samples, of a minimum length of 0,5 m, using the impact test apparatus described in IEC 60811-1-4

A heating cable having a non-circular cross-section shall be so positioned that the impact is applied along the minor axis

Heating cables and heating cable sets according to class M1 shall be subjected to this test with impact energy of 2 Joules

NOTE 1 This may be achieved e.g by a falling mass of 500 g from a height of 400 mm

Heating cables and heating cable sets according to class M2 shall be subjected to this test with impact energy of 4 Joules

NOTE 2 This may be achieved e.g by a falling mass of 1 000 g from a height of 400 mm

This test also applies to connection splice, end-termination and cold lead which are factory mounted or intended to be field assembled and accessories specified by the manufacturer

After the impact test, the test piece shall be capable of withstanding, without breakdown, a voltage of 1 500 V a.c for 30 s and according to the procedure in 8.2.2.2

For cables with metallic or other equivalent material, screen, armour or sheath the voltage shall be applied between the conductor(s) and the screen, armour or sheath and the apparatus

For unscreened cables, it is essential to submerge the test pieces in water for 5 minutes prior to applying the test voltage, ensuring that the test piece remains in the water and that the earth is connected to the water during the process.

All samples shall pass the test requirements

If any sample fails to meet the requirements, two additional complete sets of samples (3 + 3) will be tested The cable will be considered compliant if both sets pass the testing criteria.

Cold bend test

The cold bend test apparatus, depicted in Figure 3, utilizes a mandrel with a specified radius or the manufacturer's minimum bend radius A heating cable sample is secured in the apparatus and placed in a refrigerated compartment at –10 °C or the lowest recommended installation temperature for at least 4 hours Following this, the sample is bent 90º around one mandrel, then 180° in the opposite direction over a second mandrel, and finally returned to its original position, ensuring all bends occur in the same plane This bending cycle is repeated three times, with each cycle not exceeding a duration of 5 seconds.

This test only applies to the heating cable and the cold lead, if any

Conformity is verified by testing the electrical insulation in accordance with 8.2.2.2 without submersion in water for screened cables and with unscreened cables submersed in water for

5 min before the test voltage is applied, with the test piece still in water

The installation instructions provided by the manufacturer shall state the minimum installation temperature and the minimum bending radius

3 mandrel d cable diameter or thickness for primary bending plane

Ageing test for insulation

The insulation shall be aged in a heating cabinet according to 8.1.3.1 of IEC 60811-1-2:1985

Unaged and aged samples shall be tested for tensile strength and elongation at break according to IEC 60811-1-1

The ageing shall be performed for 14 days at 135 °C

The unaged value for the tensile strength shall be minimum 12,5 MPa

The unaged minimum value for the elongation at break shall be minimum 150 %

Tensile strength and elongation at break must not vary by more than ±25% from their original or unaged values.

Ageing test for non-metallic sheath

If provided, the sheath shall be aged in a heating cabinet according to 8.1.3.1 of

IEC 60811-1-2:1985 Unaged and aged samples shall be tested for tensile strength and elongation at break according to IEC 60811-1-1

The material has to pass the test described in method A or method B, as described below

Method A: the ageing shall be performed for 60 days at 10 K above the manufacturer’s defined maximum cable surface temperature, but at least at 110 °C

The unaged value for the tensile strength shall be minimum 10 MPa

Tensile strength and elongation at break must not deviate more than ± 25% from their original, unaged values.

Method B: the ageing shall be performed for 14 days at 35 K above the manufacturer’s defined maximum cable surface temperature, but at least at 135 °C

The unaged value for the tensile strength shall be minimum 10 MPa

Tensile strength and elongation at break must not deviate by more than ±25% from their original, unaged values.

Compatability test

A complete cable sample shall be aged for 14 days at 110 °C

Three samples shall be tested from the insulation and sheath

Tensile strength and elongation at break for both the insulation and sheath must not vary by more than ±25% from their original, unaged values, as measured according to specified standards.

UV-resistance test

Three samples of the outermost components of the heating cable or heating cable set shall be tested with the apparatus described in ISO 4892-3, using type 1A (UVA-340) fluorescent UV lamp

The samples shall be exposed to UV light for 8 h at 60 °C followed by 4 h of condensation at

50 °C This cycle shall be repeated continuously for a total of 2 000 h

After ageing for 2 000 h, a visual inspection for cracks shall be performed

This test is applicable to all cables, except those specifically indicated by the manufacturer as unsuitable for outdoor use or exposure to other sources of UV radiation.

Heating cables having a continuous metal sheath with no outer non-metallic sheath shall be exempt from this test

Heating cables that are only intended for being embedded in mortar or inside a floor or ceiling structure shall be exempted from this test

An alternative UV test utilizing a Xenon-arc light source is outlined in ISO 4892-2 The next revision of this standard will consider a test procedure and requirements that match the severity of the current methods.

Tensile test

Heating cable samples, including cold leads and splices (either factory-made or field-assembled), must undergo testing on a tensile machine with jaws similar to those depicted in Figure 4 The samples should be positioned in the jaws as illustrated, with an initial jaw separation of 150 mm.

The jaw separation rate must be set at 50 mm/min, while continuity of the conductors will be monitored Samples will undergo continuous examination for any signs of failure in the cable's components, with the initial load at which failure is detected considered the failure load.

Three samples shall be tested and the minimum measured failure load quoted as the test result

All completed cables shall be subjected to a tensile test and shall withstand a minimum force of 120 N

Furthermore, cables designated mechanical class M2 shall withstand a minimum tensile force of 300 N

Figure 4 – Jaws for tensile machine

Reverse winding test

To ensure proper winding of a completed cable, it must be placed on a mandrel with a tensile load to create a close helix of at least three turns The mandrel's diameter should be six times the overall diameter for both screened and unscreened cables, and 15 times for armoured cables, or according to the manufacturer's minimum bending diameter specifications For flat cables, the minor dimension should be used instead of the diameter.

The complete test consists of six cycles, where the cable is wound onto a mandrel, unwound, and then rewound in the opposite direction, ensuring that the cable's surface transitions from the inside to the outside of the helix Following a visual inspection, the cable should show no signs of damage, with minor puckering of the sheath not deemed a failure.

On completion of the reverse winding, the test piece shall be subjected to the dielectric test in

8.2.2.2, but with a water immersion period of 1 h prior to the voltage test

The dielectric test shall be performed between conductors and between conductors and screen as applicable

Heat shock test

The cable's heating section must be wound around a mandrel with six turns, each turn measuring six times the sample's outer diameter, and then placed in a heating cabinet at 150 °C for one hour If the individual turns of the sample melt or adhere to one another, the test should be conducted at 125 °C for eight hours.

Three samples shall be tested

There shall be no cracks in the outer layer visible by visual inspection.

Shrinkage test for insulation and sheath

Two samples,each 200 mm in length, shall be tested according to IEC 60811-1-3

The test shall be carried out at a temperature of 130 °C for 1 h

The average shrinkage of the two samples shall be less than 4 % b) Sheath

Two samples shall be tested according to IEC 60811-1-3 The length of the samples shall be in accordance with IEC 60811-1-3

The test is carried out at a temperature of 130 °C for 1 h

The average shrinkage of the two samples shall be less than 4 %.

Hot set test

Cross-linked insulation and sheathing materials shall be checked for cross-linking degree by the hot set test method described in IEC 60811-2-1 at a temperature of 200 °C

The maximum allowable elongation under load shall be 175 % and maximum permanent elongation after cooling shall be 15 %.

Cyclic ageing test for the heating cable

Heating cables designed for installation in screeds or concrete must undergo a cyclic ageing test This test involves five samples of the non-metallic outer layer of the cable, prepared in accordance with IEC 60811-1-1, and is conducted over a period of six weeks under specified test conditions.

– dry ageing: 120 h at 120 °C in air;

– wet ageing in an alkaline water solution at 50 °C for 48 h

The water solution must have a pH greater than 12 and consist of potable water, calcium carbonate (CaCO₃), and calcium hydroxide (Ca(OH)₂), with the pH adjusted using Ca(OH)₂ Samples should be placed in a jar filled with this water solution and then heated in a cabinet in accordance with IEC 60811-1-2 standards.

NOTE 1 It is recommended that the jar be covered with aluminium foil or a lid during the ageing period for reason of evaporation of the fluid

NOTE 2 50 g of CaCO 3 per litre and 2 g to 3 g of Ca(OH) 2 per litre of water has been found as approximate amounts to achieve a saturated solution of CaCO 3 and the necessary pH of the water solution, but adjustments may be necessary after each cycle due to evaporation of water The pH is tested by using commercially available pH-paper with good sensitivity in the alkaline part of the pH-scale

After 6 cycles the tensile strength and elongation at break shall be measured according to

The variation from unaged samples shall be less than 25 % for the tensile strength and 25 % for the elongation at break.

Cyclic ageing test for splices and end seals

Five dummy samples of heating cable sets, measuring between 0.25 m and 0.5 m in length and designed for installation in screeds or concrete, will undergo a cyclic ageing test for six weeks These samples include incorporated end seals and/or splices and will be tested under specified conditions.

– one cycle = one week in alkaline water solution

The water solution shall have a pH >12 and be made of potable water, CaCO 3 and Ca(OH) 2 , adjusting the pH with the Ca(OH) 2

NOTE 1 It is recommended that the jar be covered with aluminium foil or a lid during the ageing period for reason of evaporation of the fluid

NOTE 2 50 g of CaCO 3 per litre and 2 g to 3 g of Ca(OH) 2 per litre of water has been found as approximate amounts to achieve a saturated solution of CaCO 3 and the necessary pH of the water solution, but adjustments might be necessary after each cycle due to evaporation of water The pH is tested by using commercially available pH-paper with good sensitivity in the alkaline part of the pH-scale

The samples shall be placed in a jar at 50 °C for one week in a heating cabinet according to

According to IEC 60811-1-2, it is essential to cover the jar with aluminum foil during the aging period Once this period is complete, allow the jar containing the samples to cool naturally to room temperature Subsequently, measure the insulation resistance between the conductor(s) and the screen, as well as between the conductor(s) and the water solution or earth.

The insulation resistance shall be measured in accordance with 8.2.2.3

The measured value shall never be less than 50 MΩ.

Checking of the durability of markings

Compliance shall be checked by trying to remove the marking by rubbing lightly ten times with a piece of cotton wool or cloth soaked in water

The marking shall be legible with normal or corrected vision after the test has been performed.

Abrasion test

Deformation test for insulation and sheathing materials

The tests shall be made according to IEC 60811-3-1 and at a temperature of 90 °C both for the insulation and sheath

The deformation shall not be more than 50 % of the initial thickness of the sample.

Routine and sample tests

Tiêu đề	Heating Cables With Rated Voltage of 300/500 V For Comfort Heating And Prevention Of Ice Formation
Chuyên ngành	Electrical and Electronic Technologies
Thể loại	Standards Document
Năm xuất bản	2009
Thành phố	Geneva

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Số trang	62
Dung lượng	1,13 MB