APPLICATIONSThe R4140 Flame safeguard Programming Controlsprovide flameout prolec\ion plus aul.omalic sequencing ofthe burner motor blowsr.. R7247A GREEN Foa f!lAME RODS, PHOTOCEllS, ANO
Trang 1through the LS HTA However,11a Ilame isnot establishedand2K OOesr'l'tPJII in.2K2stays closed andtheLSHTAcontinues10 healunlll thelockOLlI switch trips.(Iftheflame
~ 0Ll1and2K drq>s OLlI, thesamething will~.)
When this~s,Contact LS2opens andload relay 1KdrClp5out. AlSO.contaci L$1 clos9s.energlzlngan exler·nal line voltage alarm (il connected)
When 1K drq>s out, coolacllK3 opens, 60 lhe lQ1itlonlransformer, pilot, and main1ueIvalve(s) cannotbeener-gized and lhe burner cannol: be slarted Contact 1K1q:oensand 11<2closes, starting Ihe timer motor (IhrOl.JlttM1and11<2).Theprogrammerwill complete its cycle andSlop 11cannot start another cycle untllihelockoutswitch
1$manuallyrG6EII.
(COAO IllCAVI
.,ICll;l$fSI\IUR
whiChi$aoout ,0.06ampere 'ora 120volt progammer
However, current I, Is not enough to heattheLS HTA
The impedanceofthe1KA section of the load reray coil is
about 100 times the resistance of theLStiTA,sothe
cur-rent can bErapproximated by the 8qJatioo
FIG 27 - CURRENT WHEN THE LOCKOUT SWITCH
HEATER IS HEATING•
SAFETY INTERLOCKSStart, PreigliUon, Running, LockOLd.H~Are, orLowFlre Interlocks may beusee!toshutdOwnthe burnertt an
FIG_ 28- TYPICAL PROGRAMMER OPERATION
CURING SAFETY SHUTDOWN
SAFETY OPERATION IF A LIMIT OPENS
An exlernal limil swilch is usually usee! to cause aOOmef shuf<bwn in case a dangerous, Pf&(.t3:tennk1ed
condition occurs Inthe conlrolled medh rn For e1:8JTl)le,Ifthe pressure In a bailergets too hlQl orthewaler levelgetstoo low.wewanl tostophealingthebailer Generally.severa! limit switches are used to monitor severalcondI·lions l't1e5a limits are conneeted In Mrles with the bJrnereonlroller If one opens It causes the system tost'lutOOwn,just as U'IOlJQh the demand for healhasstq:lpEld (which,indeed, Ithas).When normal conditIons aToll restored theIimit(s) closesandthe programmer restarts lhe burner Toprevent lhe P'OQrammer from recycling tt a limit keeps
~Ingand ClOSing it Is deSirable to use manual resetlimits Once one opens, it staysc.pe'luntil itIs manuallyreset This ensures thaI the condltiCl"l which causes thelimll to ~ Is detected and corrected as soon aspossible
LI'IE VOL lAGE- ~
HEA'H~I
lI2IN.C.
Fl E IlElA"
CONTACT!
2121'1.e.) t A"LS MTR
~tl)5n,'''l'A1l 11 ENl)OFPRE"lJIlGEI (lQAOIl(\AYl
FIG 26- LOCKOUT SWITCH HEATER CURRENT
AT STARTUP AND DURING I'REPURGE
Near the endof prElPJrge, llmerCOOlact M7closes in
preparation for Ignition trials Autotransformer action of
the1K relaycoJleslablishes aboutavo,,~acrosstheother
part of1K.This voltage is al60 across theLS HTR.prod.Jc·
!~a curranl ,~gi enbylheequation
8volts
Normally, as soon asthepilOt nameisdetected, relay
2K pulls in and 21<2 cpens, stepping the current flow
Trang 2abnormal orU"tSafe condilion occurs Each programmer
model has differenl circuitry tQ accommodate differWlt
typeS01interloCks
Generally, a programmer prOVides circuits for either
Start 01 Preiglltion Interlodcs.andeffher Running or
lock-out Inlertocks Opening 01 these Interlocks may cause
eUher recycle orsafety shutdown, depending on the
pro-grammer model
AprogrDrmier also may proviQe for borh High Fire anc::t
LowFireInter1~ks.onlyaloWFire Interlock, or neither If
any 01 these Mng rale interlocks doesn'l close at lheprq?8r time during prepurge the programmer stops be-
Acomplete descriptionottheq?8ralion01 theselocks maybefound In the Detailed Operating sequencesfor the R4140G1007, torm 60-0443 R4140L1147 lorm6().{)444 and R4140M1004 form S0-D445 Each oftheseprogrammer models provides circuits tor a different com·bination of interlocks, so all three ptblicafions are neces-sary for an explanation of all sixtypesof Interlocks
Inter-R4140 PROGRAMMING CONTROLS
DEVELOPMENT OF THE R4140 FLAME
SAFEGUARD PROGRAMMING CONTROLS
Way back In 1931, HQl"lEllljWeli inlroc1Jced the firm
elec-Ironic flame satfo,Jard control-the Protecloglosystem
This systEm replaced the mechanical, bimetallic systems
which were Inhetent'Y-slow in responding to flame faiture
Instead of a bimetallic elemeril, ituseda flame roo which
q?8rated on the flame cord.Jctivlty principle
In 1941, Honevwell develq:l8Cl a circuil that operated
on the flame rectificallon principle and eliminated the
shortcomings01the flame conductivity circuil The flame
recll1icalioo circuli also permitted the use of a photocell or
a flame rodasa flame detector (For an explanationotthe
flame conc:UCllvltyandflame rectification circuits, refer to
the Flame safeguard Reference Material on Flame Rod
.AWlicatlCl'l, form 7C~·8108.)
To provide the capability of detecting bcllh a gas pilot
and a mail'! oil flame with'a single delEtctor, the infrared
(lead sulfide)flame deteclor was develq:l8Cl in'952.This
detectorwasthe first one to use an amplifier to process the
flame SllTlilf
To a1irninate thehot refractory hold-In problemSOIT1e'
limes encounlered with photocells or infrared flame
detec-tors, Hor"lElywe" developed' the •pl)(ple peeper~
ultravlolel flame delector In 1957_ This was the tirst
ultra-vlotet flarM deteclor used In flame safeguard syslems
In 1962, Honeywell intrcxiJced lis first Flame
"Thesecontrols used the same type01synChronous
ma-tor-oriven Ilmers which are used on alT"Honey.,veli
pro-grammers, excePl lhe BC7000 They also incorporated
plug in flame signal amplifiers thai couldberaadily
Inter-changed to allow Ihe use01any type01flame
detector-flame rods, photocells Infrared detectors or ultra lolet
delectors
Stlortly after, Ihe R4181 Seff-Checking Programming
Control was intrOOuced This was the first complete
pr0-grammerwilh a Dynamic Self Check system The
self-CheCking circuitry was Internal, so only flame rods and
C7012E(l(F Purple Peeper Ultra iolet Flame DeteclOls
146
cwldbe usedwith the R41Bl It was nol adapted for pllJlj"
in amplifiers
The R4150 familyof programmers was intrcx:l!Ced in
1964.They were much smaller and more compact thanthe R4126and R4127 ~i~.Ialuri;ed. solid stale, pll.)Q-inflame signal amplifiers maintained the interchangeabilityfeature Theamplifiers were also Kpol(ed~ for ar.t::titionalr~ElSS andmoisture resislance
• In 1971 a solid state Dynamic SelfO1ackplug in fier (the R7253 B) was inlfoduced The self-checking func-tion could now easily be added fo R4126 R4127 andR4150 programmers which feature the fleXibility ofinter-changeable, plug-in amplifiers
ampli-Finally in 1974 Honeywell Introduced the R4140's
Theyhave all the features of previous programmers, plusseveral new ones The plug in amplifiers have been fur"ther miniaturized.andare now available in 6 models, in-Cluding Dynamic SelfCheck and DynamiC Ampli-Checkmodels
The R4140's have been designed to replace lheR4126, R4127, R41a" and R4150 Flame safeguard Pro-gramming Controls
APPLICATIONSThe R4140 Flame safeguard Programming Controlsprovide flameout prolec\ion plus aul.omalic sequencing ofthe burner motor (blowsr) firing rate molar ig1iUon pilotvalve.andmain fuel valve(s) for commercial and lrd rstrlalburners using gas oil coal, or a combinali()fl of fuels.They incorporate all the timing changes required by theOctobal 1 1974 revisions to Underwriters laboratoriesInc Standards for safety-UL 296for all bUrners and UL
795 for commercial-indJslrial gas-heating eqUipment.Con eniently the R4140 familyhaSbeen developed inmodels of varying COl1l=llexlty This allows the user 10ctxx:tse the ~impl8Stprogrammer fhat will meet his awli-cation reqJlraments (Table I)
Trang 3TABLE I-PROGRAMMER APPLlCA110NS
I
IHTfl'lLOCK
IrlRIII.O RATE
I
OTHER olPPllCAeU
Prapurr,: and PrOll9n High F re Purg9) H~I1l,".aro:l
"".'-"
a Ul ' _ U~.", UDo!ZO~" iIC >eqU~;
<8t> -'ao:IOl'/ ~W'lual ~l;
F I _ IndullrIaI Aif,k IJIIlftr.I(1a " , '.IAI r e q u l _
b Fb1"1l (81" "",lor _ clo by heW ~oprll'llt"llllml when ~ II s.
c ClUI;deoecl _ ulKl anynlO'"
FEATURES RETAINED FROM THE R4150
Many features that have proved successful in the
R41S0 programmern have been included intheR41<W'S
EASY MOUNTING (FIG 29)
The R4140 is small and compact like the A4150 It
mounts on the same QS20A wiring Subbase, so it can di·
reclIy replace the R4150 for most awlicalions The
pro-grammer simply plUgs Into the sutbase
20 KNIFE·ILAD£ CONTACTS
THIS SIDE IS DPEN ON" :l-5IDED QUO"IOn
FIG 30- FEATURES OF THE STANDARO
Q520A WIRING SUBBASE
WELL-DESIGNED CONTACTS (FIG 31)The R41<Wusesthe same weli<klslg'lEld contactslhalproved so successful for the R41SO, Each female springconnector on the programmer Is actually cCll'TlXlSEld of4
separate conlacts These 4 contacts wipe the knl1e-blade,contactontheSUbbasewhen the programmer is plL.Jg'JeCl
In After mounting, all 4 separate spring-loaded CClI'Kactspress againsttheknife-blade making a flrm connection Acaptive relaining screw in the programmer chassis (Ag
29) screws Into the suttJase to hOld the programmer inplace The contact design and retaining screw graartyrectJce Sf'tY fX)SSibility of an intermittent electricalconnection
PLUG-IN AMPLIFIERS (FIG 32)Ukethe R4150 lhe R4140 incorporatesplug-Inflameslgnal amplifiers that are InterCl"Iangeabletoallowtheuse
ofany typeofflame detector-flame rod,photocell
InI'ra-
RETAINING SCREW
FIG 29- THE R4140 MOUNTS ON THE SAME
Q520A WIRING SUBBASE AS THE
R4150
STANDARD SUBBASE (FIG 30)
The standard Q52QA Wiring Slibase has 20
knife-blade contacls to 'accommodate the mostcomplexR41<W
The4.-sided Q520A1121 shownhaS8knoCkouts for
brino-ing In wires The 3-Sided Q52OA1089hasan~sldefor
even more wiring room
Trang 4Ill'll f£·BLAO£ CONTACT
ON SUBBAS£
• 5EPARATE 5PRING·1.0AOEO CONT ACTS PIIIE55 AGAINST KNlfE·BI.AOE
• FEMALE SPRING CONNECTOR
ON PROGRAMMER
OPTIONAL METAL COVER (FIG 32)
An optional, heavy lirty, melal cover (Part No.1396958
orC) is available for oulside panel mounting This cover
has a resel l::utlon so 1I ooesn'l have 10be removed 10manually reset the lockout switch
METER JACK (FIG 32)
A meter jack onthearrpifier provides a means of plultging In a mlcroamme!er 10 measuretheflame signal withthe system In cperatloo
TIP JACK (FIG 32)
A tip jack on the programmer allows the use of a flamesimulator during troubleshooling
PUSH·TO·RESET LOCKOUT SWITCH(FIGS 32 AND 33)
The lockoul swilchpcJ;JSout when II trips, and simplypushes Infor reset.An inverted·V·construction makes itnearly ifTllClSSible 10 grasp it and damage itby pulling IIout. II Is Mclased In aeust·resislant case to lessen thepossibility of contaminalion field damage, or jamming/purposely making lhe swllch lnoperallve)
45EPARATE C.ONTAC.T5
.4 SEPARATE SLIDING CONTACT5 WIPE KNI FE-BLADE AS
PROGRAMMER IS PLUGGED IN.
FIG 31-CONTACT DESIGN FEATURES
I -;.' PI.UG~N Fl.AME SIGNAl.
AMPLlflEIIS ARE INTlEIilCHANG£ABLE \ RE5ET BUTTON
fOR LOCKOUT SWITCH
OI"TIOfoI"'L,.ME"'VY OUTY•
£1 1 COVER "OR unOlinlOE
TIP JACK fOR HAW SI"ULATOII
,
• INVERTED v CONSTRUCTION HELPS PREVENT ANVoNE fROM PULLING OUT "'NO C GING SWITCH
• OU5r·R[SrSTAI'H CASE LESSENS POSSIBILITY Clf CONTAI'IIN'" flON FIELD O"''''''G£.
OR J MING (M"'I<,I"G SWITCM INOP(R TIV(1
FIG.33- FEATURES OF THE LOCKOUT SWITCH
FIG.32- R4140 FEATURES LIKE THOSE OF
THE R4150
red or ultraviolet These amplifiers are color·coded forld91tificatlon, solid state for ruggedness and reliability,and fully enclosed 10 help prevent conlamlnal1on, tamper-Ing, or etamageln lhe field (AmplifierImprovements willbe
discussed In the nelt! 6EIction.)
TIMER DIAL IS ROTATABLE AND MARKED INWORDS (FIG 34)
TIleIimer dial canberotated manually in the field, withthe relay/llmer cover on orott.An arrow on the cover indi-cates the proper direction of rotalion
Descriptive words (rather than numbers) on the timerdial Indicate the period 01 the programmer S8QJence.Plastic Shrink film covers the dial to prevent 6EIrvice technI-cians wilh oijy hands from n.t:bingoNIhe markings
'48
Trang 5TIMf.R OIAI CA" Sf.
SEQUENCE PERIODS MARKEO IN WOROS- PI.ASTIC COVEREO TO PREVf."T RUBBING OFF
ADDITIONAL FEATURES
The A4140's include several lf11)rOvemenls 10 makethem more flexible and easy-to-use
EXPANDED AMPLIFIER CAPABILITY (FIG 35)
The plug-in flame siglal aJT'4)li1ler capability incrudes 3standard models, 2 DynamiC Set! Check models, and 1Dynamic Arll)1I-Qleck mrxieL (Refer 10 Table II tor ac0m-plete listing01the flame detecllonsystemsavailable.)Each ampllflerhasa label with the recoovnended mini-mum flame siglal Qnmicroamperes)
All self-checking amplifiers have a red Indicating lamp(hat blinks when aflame ,Isbeing detected
ACCESSIBLE RELAYS (FIG 36)
AUrelays are visible, labeled,andaccessible whenthe
relay/limer cover Is removed This allowstheservice nician 10 walch relay cperallon and facilitares checkoutand troubleshooting
tech-FIG.34- FEATURES OF THE TIMER DIAL
R7247A
GREEN
Foa f!lAME RODS,
PHOTOCEllS, ANO C7012A,C
PURPLE PEEPER OETECTORS
FOR FLAME RODS
(MAY ALSO BE USEO WITH
PHOTOCELLS AND C7012A.C)
R7247C OYNAMIC SELF CHECk
GREEN FOR C7012E,F PURPLE PEEPER ULTRAVIOLET FLAME DETECTORS
R7248B OYNAMIC AMPLI-eHECJ(
REDFOR INFRARED OETECTORS
7564FIG 3S-PLUG-IN FLAME SIGNAL AMPLIFIERS AVAILABLE FOR R4140 PROGRAMMERS
Trang 6TIMER CAMS CAN BE ADDED (FIG 36)
Extra~ceonlh9 programmer chassisallowScamsto
beadded10 lh9timet wifhoutredeslgtThI6maybe
nec-essaryIf moretimercontacts are nq.J1red tomEleIfuture
COdes.
ALL IlELAVS A,RE VISIBLE.
LA,BELEo A,NO.ACCESSIBLE
'.0
FIG.36-ADDITIONAL FEATURES OF THE R4140
TIMER SWITCH (FIG 37)
A limer switch lets the c:perator stop the Iimer near the
end of prepurge or during the PUo! Flame-Establishing
P&-ried 10 facilitate checkoUl and troubleshooting.Theswitch
win nol slop the Iimer when the main fuel val~e/S) is
TIMEII SWITCl-I TO HOI'
T"'IE~ FOil CHEC~OUT
FIG.37- MORE ADOITfONAL FEATURES OF THE
R4140
RELAY(TIMER COVER (FIG 31)
A metal cover helps prOlect the relays and limer cams
The cover easily snaps on or off There are no screws 10
remove
150
SPRING CLIP TO HOLD AMPLIFIER (FIG 37)
A spring clip on the relaylllme1cmersecurely hold theplug-In flame slgtal arT\?lIner to ensure good electricalconnEilctlons
MODERNIZATION WITH THE R4140The R4140 Flame 5af9QU8.rd Programming Conffolsare Idealfor replacing older pt0g'8JlY'ners thai no longermeetlhe f8CJ,llremenis01~roval agenCies Theyincor·porateall the lfming changeS rllqJlred!:PIthe OCIet:ler 1,'974, revisions to Underwrltel'$ laboratories Inc Stan-dards for 5afety-UL296foroNburnersandUL795 forcomrnerclaHnduslrlaJ gas-heating 8(JJipment Thus,theyare excsllentfor convertlf"Q systems10differenl fuels.Th&
R4140lls perfect for L pQradingasystem10meet FactoryMutual and Induslrial Risk Insurers (formerly F.I.A.) re-qJiretTlQ"lts (Refer to Table I for other applications Inmeeting awroval to::ly requirements.)
With the flexibility providedby thepklQ-lnarT\?lif'iers,the pfq:l8r programmer and flame delecllon system canreadily be selected to meet the speclfiCaliOl'l$ and localcodes on almostanyjob For reliability and long life, allmodels 1ealure heavy dUty timers, relays, and contacls as
waJlassolidslale flame signal arT\?flflers
In adcIlUon, TRADELINE models have been developedthaI make il easy \0 stalX:lardize Standardization allowsdealers to reduce their serviceandspare parts inventory.Because lhere are 0I11y a few models,it is easier and1aSier
to train installers and seNice techniCians Some of lheseTRADEUNE models can easily replace certain competi-tors' devices by uSing specially deSigned replacemenrpackages
FLAME DETECTION SYSTEMS (TABLE II)Theflexibility provided by the lnlerchaf'lgeable, plug-inflame signal amplifiers is llvidenlln Table II Aslandardor
a self.Checkin'Ol delection syslem is available 10r burne:susin'Ol any type of fuel-gas, oil, or coal
NOTE: TableIfIs subject 10 change to Include new devel·opments or to reflect requirement modificalions Forlhe lalesl sys:ems available, refer to the table In the in-struction sheel packed with Ihe programmer
TRADELINE MODELS (TABLE III AND FIG 38)seven TRAOEUNE A4, 40 models can replace sev-enty A4150 models A cross reference is Included in eachTRADruNE JnSlfuCJionSheel Twvc ad:::1ilional screw fer-minals on the backs of some of the programmers prOVide athird choice of the Main Burner Flama EslablishJng Pe-riod (Consult the awropriate Instruction sheet for furtherinformation.)
SUPER TRADELlNE Y4'40 Modernization Packages,containing one of the 120 voll TRADEUNE R4140 modelSand a Q52QA1'21 Wiring SLtbase, are also avaifable.They also contain cocle requirements, installation instruc·lions, wiring matrices, and preprlnlud wire markers Com·plele packages also inClude either a plug-in infraraclampl11ier and matching flame detector, or a plug-in reclifl·caliOf'l amplifier Par1ial packages withoUl the deleclorand/ct amplifier, are also available (For further informa-tion, consult the Y4140 mslrt/cliOn sheet, form 6o-D574.'
Trang 7TABLE II-FLAME DETECTION SYSTEMS
R7247A'b 2to4sec
Oil, Gas,R7247B
R7247c!
Coal Peeper)
Gas, Infrared
Ultraviolet (Minipeeper) C7027, C7035, C7044 Ultraviolet
Blue
Dynamic
Gas, Oir,
Ultraviolel (Adjustable C7076
a Circuitry tests all electronic corrp:ll'I8nts in the flame detection system (ampliller and detector) 60 to 120 limes a minute during burner ClI')eration and shuts down the burner il the detection system fails
b Circuitry lests the flame siglal amplifier at least 150 times a minute during burner operation and shuts down the burner it
the ~lltier.fcl'lIs
c Order flame rod separately; see Instruction sheet lor the holder
d Use Honeywell photocell, Part No 38316, only
TABLE 111-TRADEUNE MODELS AVAILABLE
TRADE LINE
MODEL
INSTRUCTION SHEET FORM
NO
NUMBER OF R4150'S
IT CAN REPLACE
MAIN BURNER FLAME-ESTABLISHING PERIOD
IN SECONDS (FielD SelECTABLE) R4140G1114 a
Trang 8& .,1lO\i "00£1.5 HAVE NO l[R"'NAI.5 "AND 16
FIG 38-REAR VIEW OF MODELS WITH 3 CHOICES OF THE MAIN BURNER FLAME·ESTABLISHING PERIOD Y593 REPLACEMENT PACKAGES (FIG 39)
EiQht Y593 Replacement Packages are designed to re
place 64 different models of a compelilor's flame sale
adapter base to make replacement as easy and conven
ient as possible No eXlernal wiring changes are neces
sary for most fl"ICX:iels After the removal altha compelilo(s
conlrol, the adapter base is mounted directly on the exist
ing &.tbase or in the existing Cabinet The TRADELINE
R4140 included in the replacement package is simply
plugged into the adapter base (Cons\.l'lt lhe Y593 instruc
tion sheel, form 60-0407, for further information.)
INSTALLATION OF AN R4140
The bask sleps in the installation of an R4140 are
(1) mounting the wiring Sl.t:lPase (.2) wiring \0 sutbase,
(3) installing the flame detector, (4) performing a static
checkout, and (5) mounling the programmer These steps
will be desCribed in general in this sectiOl1 During an ac·
lual installation, follow the applIcable instructions pte>
vided by the burner manufacturer in addition 10 those in
the instruction sheet 'or Ihe particular model being
Installed
MOUNTING THE WIRING SUBBASE
First, ChOOSe a location where the temperature will stay
wilhin specification limits for the R4140, and where the
re/antle humidity never reaches the saturalion lX>inL C0n
densation 01 moisture on the R4140 could cause enough
leakage to short the flame signal to ground and thus pre-
venl the burner from starting Locate the sutbase close to
the name detector(sj in order 10 keep Ihe flame signal lead
wires as short as possible 00 not Inslall it where II could
~(T"'NING SCR(W KNIF(-BlADE CONTACTS (NGAGE FLAM( SAFEGUARD
be subject [0 extreme vibration Vibration shortens the 1I1e
01 the eJaclronic comp::lnents Finally, the R4140 is not weathartighl, so prolection wilt be required If it is installed O!.JtdOOrs
152
Trang 9The sut::oase can be mounted in any position except on
a horizontal surface with the knifErblade contacts pointing
down; the relays on Ihe programmer cb not operate prop
erly if il Is mol,.Jnted in this position The standard moonling
position for the programmer Is on a lr&I1ical surface with its
handle up as shown in Fig 41 Ani other posilion de
creases the maximum awt:lienl terJl)Elrature raling
Whan yOu selec! the Iqcatlon on a wall or instrument
panel be sure to allow clearances for servicing and tor re
moval of th~ progrartlmer - it swings out Use the back of
the sutoase as a template to marl< the 4 screw locatiQf1s
and drilllh~ pilot holes (If mounting the sutoase in an ex
isting C3binet, new holes may not be necessary.) Start the
mOLintlng screws and scr~ them most of IMe way In [fhe
sutOase has keyhOle type mounting ho.'es so the mount
In'il screw,s can be statted alone.) Fil the subbase over the
screws and ,tighten them securely
WIRING TO THE SUBBASE (FIG 40)
The external devices anc:l wiring required will be differ·
ent 10r every Installation A typical wiring diagram for an
R4140L is shown in Fig 40 If one is furnished follow the
burner manufacturer's wiring diagram Remember that all
wiring must comply with all applicable local electrical
codes ordinances and regulations, and it must be NEC
Class 1 (line voltage)
An Important thing 10 remember is
Do not run high vol/age ignirion transformer wires in
the same conduit with the flame detector wiring
Check all wirin'il circuitsa(kj perform a Static Checkout
before mountin'ilthe programmer Make sure the wiring to
any terminal does not touch any other terminal Especially
make sure the wiring 10 termjr.aJ 7 does nor touch
terminal 8
INSTALLING THE FLAME DETE.CTOR
Proper flame detector installatlon is the basis of a safe
and reliable fla,mo sal9l;)Jafd InstaJlati::ln Refer to the in
structions packed with the flame delec.tor and amplifier,
and to the burner manufacturer's instructions Follow the
Instructions carefully to'maka the best possible applica
tion of the flame detector
Keep the name Signal leadwires Irom the flame detector
to tfJe terminal strip or win'ng subbase as short as possible
capaCitance Increases with leadwire length redUcing the
si'ilnal stren'ilth The I'TIaXlmum permissible leadwire
len'ilth depends on the type oflaadwlre, conduit, a(kjtlame
detector The ultimate limiting factor In Dame signal lead
wire length is the Signal current Refer 10 Table V
For detailed diSCussions on flame defector installation,
refar to the Flame Safeguard Reference Materials on
Flame ADd Application, form 7Q-.8108, and Optical Detec
tor Application form 7()'8109
PERFORMING A STATIC CHECKOUT (TABLE IV)
After checking all wiring circuits per10nn a checkout of
aU eXlernal devices before mounting Ihe programmer on
the subbase These teslS ensure that the wiring subbase
is wired correctly a(kj lhat lhe external controllers, limits, inlerlocks, valves transformers, and molors are qJElrating properly TneV Can be made ri't1't at the sutoase by Install· ing jumpers and reading the voltage between the proper
terminals Remember that line .oItage is present on most
terminals when power is on, so be extremely careful when
performing these tests Follow the instruclions In the in·
struction sheet for the R4140 .e!}' carefully The tests shown in Table IV are typical lor an R4140L Tests for other models are similar, but all of them may not beappli· cable, and some ot the terminals may be different MOUNTING THE PROGRAMMER (FIG 41)
Be sure to open the master switch to remo e power from the subbase terminals before mounting the program mer Also make sure that
- there are no bare (unlnSUlaled) wires in lhe suttlase -the Wiring to any terminal does not touch any other terminal
- no sut:Oase wiring is protruding out beyond the lerm1· nat blocks
- the wlrin'il does not interfere with the connectors Tuck all wiring In againstlhe back 011he subbase After you have checked all the wiring, grasp lhe handle
of the programmar chassis anc:l engage lhe Chassis hinge braCkets with lhe pivot pins at the ooltom of the S<.tbase Swing the chassis inward until lhe spring conneclors engage lha knifErblade contacts on the sutoase Push in until the contacls are fuJly enga!J8d Tighten the chassis relaining screw securely
REMOVING AND REPLACING THE RELAYIT\MER COVER (FIG 42)
The operator may wanl to remO\'e the relay/time cover
10
- install or change a ptug-in 11ame Signal amplifier
- observe relay anc:l timer qJElralion
- Inspect ralay or timer cootacts
If the programmer is mounted on the subbase make sure the master sWilch is qJEln before removing or replacIng the cover
REMOVING THE COVER
1 Grasp lha relay/timar cover and 5ql.JBeZe until the Vnotch on the cover slides tree of the stud on the handle
2 Rotate the cover dlwn a(kj oot to disengage the 2
tabs 1rom the slol in the ooUom of lhe programmer chassis
3 Pull the cover oul
REPLACJNG THE COVER
1 Insert the 2 tabs on IheooUom of the covarbalween the timer and the programmar chassis and engage them with the slot In the bOtiom oflhe chassIs Make sure the labs are nol jammed in the slot
2, Rolale the cover up anc:l in, so the V-nolch slides along Ihe stud on the handle If the cover does not rotate easily, the tabs are jammed
3 Maka sure the spring clip on the cover fits O\'er the plug-in ampli1ler
4 Push in on the caver until the V-nOlch snaps into place on the stUd
153
Trang 10& "' ~u NH'~""" I.'RI~,,_
& FOR 0'''''' ••TU"'''''L' ~A ' "'0" (Ol~ OR , "'''''"In " " 'o~ ~o
.~" ,.IN '~'l V.~V!('1 HI ,,_ ' 'u ~
n~"'''''L' to T,RMINAL • ",'HJU
.& FOII'~ uco.a ""T£"~UI'TED.'~OTI'D"'lION,""T~LLJU" " (IN_
'Wa'o IN '"''.v.''''' "'U~.CYI "" B.CO< Of "OG~.""'R .,
T ~ """." "'N.li >fL.D 'V •0 U'TIJOl) '" «ON
~
L"" ."'''c~ ,,~( f
FIG 40-SAMPLE BLOCK DIAGRAM OF FIELO WIRING FOR AN R4140L PROGRAMMER
Trang 11Linlt IIOltage at terminal U
linlt -ollaglt at tarminal 4
LinB IIOltage at terminal 16
1 BurnBr rnobr (Ian or bloWer) starts
2 line IIOllaqe at terminal 3
-1.lgnitbn spar1( fit ignition trans
former is connected 10 larminal
5)
I 2 Automatic pilot wive opens (II connected fo tem1inal 5)
NOTE: ReM" tJ schEmatic dia
gram of the programmer model being ~d
Same IS TEST NO.5 br connec
oons tJ tBrminBJ 6 (tI using direct spar1( igniOOn, ,""' the main fuel lIaJve(S) instead 01 !he piklt
1 Mastltr switch s closed,
2 F'owltr is connected to the mastllr ~h
3.0ver1(lad protection (luse, circuit break.er etc.) hes oot 0pltned the power line
IMPORTANT low fuel pressure limits, it used, could be open Bypass thEm with jumpltrs for the rest 01 the Sta~c Tltsts (It required)
1 limits closed
"open determine
'"
causers) and correct the condition{s)
2 Burner controllltr is closed (call lor heat)
1 PrBignition interlock.s arB Closed II open determine cause(s) and corrBCt thB condi tJoo(s)
1 Burner I1'lOIDf circuit:
a Manual switch 01 burner rnolDf is closed
b Bumer motor power supply overload prolecti:m, and starter are okay
c Burner I1'lOIDf is ok.ay
2 Lock.out im9l1xk.s Qncluding the Airflow Switch) are closed
1 Wetch for spar1( or listen for buzz
2 usten for click or leel head 01 IIUve br
8C~VBtion
a.h:lUalDr fit U:led) is okay
b Pi'ct lIalve ie okay
same as TEST No.5 (1'1 using dll1lct tpark iqnllion, check the IT\lIin fuel valYe(lf) instead
01 the pibt llllve.)
1 Listen tit and obsefve operallon 0I1he mBln IueI wNe(e) and actue.t:Ir(e)
2 Va/IIe(B) and BetuaJor(S) are ~
1.AlBrm II okay
I
Trang 12TABLE IV - continued
, '
VOLTw MODElS
TESTTEST
line ~Ilage at terminal 13 atler
All R4140L Models
2 Lower ,~ poirrt of series 90 COntroller - firing "IB mo'"
Should drtve toward ·closed.·
- Ignl1ion l!ipar1l (' ignition trans·
former is COnnected to \erminal L'-18
pressuR! limits (rf used)
1 High fire 5"I'l'Ilch lliI closl'd
2 Firing rats mo\of and trans~rmer are okay
1 Low r'rl~ IWitcM is connectsa between termi· nals 8·13 111'lJl proceed to TEST No 11
2 Low fire RWiII::h ill closed
3 Firing rail m:rtor ana transformer are okay
1 Low fire switCh is conneclad between lerminals 1&-13 H 1'lJl proceed to TEST No 12
2 Low fire switt:h is closed
3 Fir1ng rate rr'IllDr and 1Jansformer are okay
1 Series 9D controller is okay
2 Firing rats motor ana transformer are okey,
,
b.lgnition transformer is
ON COYER NOlE:
11 0LE
SPRING CLIP \
KI'lIFE_BLAOE CONT"'CTS (201
C SSIS R(T I"'''G SCRE
PROGR",MMER CHASSIS
156
Trang 13INSTALLING A SMALL PLUG·IN FLAME SiGNAL
AMPLIFIER (FIG 4J~
Two stanc1:l.rd amplifier models are packaged in a small
c
- R724 7A Rectification Amplifier (green)
- R7249A UltravIolet Amplifier (purple)
To install one oll1lese amplifiers follow these steps:
1 RemoveJIle relay/limar co er
2 Make sure the amplifier nameplate is on tile outSide,
Then align llle circuiCboard wflh the receplacle on tile
programme";
3 Align tile ends of tile amplifier witll tile 2 scribe
marks alongside the receptacle on the programmer,
4, Push in Ille amplifier unlillhe circuit board is tully in
serted Into Ille receptacle (It It doesn't Q:l in easily, clleck
llle alignment The receptacle is keyed 10 the circuit board
to pre enl Insertion if the amplifier is not alignod proparly.)
5 Make sure tile amplifier is firmly in place; lllen re
place tile relay/l'mer cover,
6 Make sure tile spring Clip on the cover fils over tile
pluQ4f1 amplifier (see Fig 42),
AMPLIFIER
\TI tR
TIMfR OIAl CIRCUIT BOARO
"'EVEI:)
RECEPTACLE ALlG, ENT
SCRIBE "'AR"-S PROGRA "'ER
Four amplifier mooels are paCkaged in a large case
- R72478 Oynamc Sej~ CheCk Aecllflcalion Amplifier
(green) ror flame rods,
R7247C Dynamic Self CIleck Rectification Amplifier
(green), for C7Q12E,F Purple Peeper Ullraviolel
Flame Deteclors
- R7248A Standard Inlrared Amplifier (red)
- A72488 Dynamic AmpI~.Qleck lnlrared Amplifier
(red)
The slaps for installing a lar\)9 amplilier are lhe same
as lllose for a small amplifier, except that the 2 Scribd' marks are nol used
"'EYED RE;CE;PTAcLE
'PROGA" ER
(;'RCUIT 60ARD
FIG 44-INSTALLING A LARGE FLAME SIGNAL
AMPLIFIER
CHECKOUT AND TROUBLESHOOTING Before the system is put inla service, the q:leralor must perform all appliCable lests listed in tile CIleckout Summary below and any others required by lhe burner manufaclurgr Instructions lor Ihe tests listed are in tile instruction Sheet for the R414Q
Before starting the burner the first time, milke sure all manual fuel shutort valves are closed Also, 'b9 siJra to
I}OOd.IIle follawlng warning:
Do not allow fuel to accumulete In the com· bustlon chamber If fuel Is allowed to enter the chamber for longer than a few second
without Igniting, an explosIve mixture could result It Is recommended thet you limit the trial for pilot to 1 Q seconds, and limit the attempt to light tile maIn burner
to 5 seconds In any case do not eltceed the normal light off time spaclfled by the burnar manufacturer; close the manual fuel shutoffval~esIf the flame Is not burn· In9 at the end 0' the specifIed time
CHECKOUT SUMMARY Tnv following lisl summari.:9S the cneckoul lests 'a
quired for each type of installalion It explains tile purpose
01 each lest and lells wilen It is ro be performed PREUMINARY INSPECnON is required for all installations to avoid common problems It sIlould be performed at the beQ:inning of lhe checkout before any otller lestS (see Fig 4510r lXlSitions of the Umerswilct", and dial at startup.)
Trang 14REl-AY/TI",tR COVtR/
FlAME SIGNAL MEASUREMENT is required for all In
stallatIons to ensure that the flame detector is sighting
the flame and lhat the proper flame sig"lal is provided to
the pr.QQrammer It should be performed thrOlJl'ttlout
the checkout procedure at the appropriate limes de
fined In the checkout tests (See Fig 46 for the meas·
urement procedure.)
INITIAL UGHTOFF CHECK FOR PROVED PILOT is re
quiredfor all installatiorls using a pilot, to ensure that
the burner lights 011 properly It should be the first lest
after the p-rel!lJJinary inspection
INITIAL UGHTOFF CHECK FOR DIRECT SPARK IGNI
TiON is required for all burnen; not using a pilot, usually
small oil butners, to ensure that the burner lights off
properly It should be the first test after the preliminary
Inspection
PILOT TURNDOWN TEST is requirecl for all installations
using a pllol, to ensure that the main burner can be ig
nited by the smallest pilot flame lhat will hold in the
flame relay 2K It should be performed ril1ll aner IhEt in
itiallightoff check
IGNmON INTERFERENCE TEST is required for all in
stallations using flame rods, 10 make sure lhat a false
signal from a spark ignition syslem is not superim
posed on the flame signal It should be pertormecl after
the Pilot Turncbwn Test
HOT REFRACTORY SATURATION TEST is required for
all Installations using infrared (I&ad sutflde) flame de
lectors, 10 make sure that radialion from hot refractory
c:bes not mask the flickering radiation of the flame ilseff
and cause satety shutdown It should be performed fol
lowing the Pilot Turncbwn Tesl and if recommended in
the troubleshooting proCedures
HOT REFRACTORY HOLD-IN TEST is reQ-lired for all in
stallalions using rectifying phOtocells or infrared (lead
sulfide) flame detection, to make sure lhat hot refrac·
tory will not cause the flame relay 2K to Slay pulled-in
after the burner flame goes out [tshould be performed
following the Pilot Turndown Test for rectifying photo
cells, or following Ihe Hot Refractory Saturation Test for
infrared detectors It may also be recommended in Ihe
troubleshooting procedures
ULTRAViOLET RESPONSE TESTS are required for all
installalioos using ultraviolet (Purple Peeper or Mini
peeper) flame detectors An IGNITION SPARK RE
SPONSE TEST is required to make sure that the
ignition spark does not actuate the flame relay 2K RE
SPONSE TO OTHER ULTRAVIOLET SOURCES
should be checked to ensure proper detector opera
tion These tests should be performed following the Pi·
lot Turndown Test
FLAME SIGNAL WITH HOT COMBUSTION CHAMBER
should be checked for all installations to ensure ade
quate flame signal under actual conditions while the
burner is firing and 10 check the flame failure response
time 1\ should be performed aner all start~ lests and
burner adjustments have been compleled
SAFETY SHUTDOWN TESTS are required for all installa
tions to ensure that the lockout switch on the program·
me/ trips and locks oul the system If an abnormal
condition occurs that reqUires safety shutdown They should be performed al the end of checkout after all other lesls have been completed
If the system fails to perform properly during checkout, the operator should note the lXlir:t at which troubla occurs and refer to lhe TROUBLESHOOTING section in the Instruction sheet tor the R4140 /lJ1 checkout tests must be satisfied with the flame detector(s) in its final IXlsilion,
Methods of flame simulation are available to aid in Iroubleshooting the flame detection system (Figs 47 and 48)
POSITIONS OF THE TIMER SWITCH ANO OIAL AT STARTUP (FIG 45)
During the preliminary inspection the operator should make sure thaI the timer switch is in the NORM position, and that the large 001 between PURGE and PREPURGE
on the limer dial is at the index notch It the cbt is not at the index ~tc.h the dial should be rotated manually, in the di
rection shown by the arrow on the relay/timer cover, to the
FIG 45-POSITIONS OF THE TIMER SWITCH
ANO OIAl AT STARTUP
To facilitate checkout and troubleshooting, the operalor can stop the timer by setting the timer switch to lhe TEST position The timer will lhen Slop nsar the end of Prepurge to allow time 10 cheCk the standard models of the plug-in amplifiers (R7247A, R7248A, and R7249A) It can also be stopped during the Pilot Flame·Establishing Period to adjust the pilot during the Pilot TurndownTest, orto check the IXlsilions of the timer and relay contacts during troubleshooting
158
Trang 15NOTE: Wilh the limer stopped during the Pilot Flam&Es
lablishing Period, the lockout switch will heal If il heals
100 long (a~roxirnately half a minute), safety shut·
doW"f1 wi11 occur
FLAME SIGNAL MEASUREMENT
(FIG 46 AND TABLE V)
When a flame detectqr senses a flame, it procfuces a
very sm.all electrical signal that Is called a Rame signal
This liny signal is fed back through leadwires to the flame
signal amplifier on the flame safeguard control, where it is
made much larger so it can be read on a meter The mag
nitude or the flame signal Is proportional to the size and
quality of the flame (providing the detector is sensing the
flame properly), so the condition or a flame can be deter·
mined.by making a Ilame signal measurement
"lEO SPAOIE TIP
\ILACI< SPACIE TIP
n,."
P\.UC-lN FU\Me:
SIGN MPLIFle:Rj
FIG 46-MEASURING THE FLAME SIGNAL
The flame signal should be lTleaSJJred at the a~rcpri
ate times defined In the CHECKOUT and TROUBLE·
SHOOTING sections of the instruction sheet for the
R4140 REiad the flamecsignal in microamps at the meter
jack on the plug-in flame signal amplifier (Fig 46) The
meter reading must be as speCified in Table V Detailed
measurement procedures are included in the CHECK
OUT section of Ihe R4140 instruction sheet
NOTE: Table V is sLbject to change to include new devel·
opments or to reflect requirement modifications
For the latest requirements, refer 10 the label on the
amplifier
FLAME SIMULATION (FIGS 47 AND 48)
During troubleshooting, It is often advantageous to
Two devices are available for this purpose:
123514A Flame Simulator-for checking out a stan·
dard R7247A Rectification Amplifier
1235148 Flame Simulator-for cheCking oul a stan·
dard R7249A Ultraviolet Amplifier
To use either of these devices, follow the appropriate procedure in the TROUBLESHOOTING section 01 the instrucfion sheet tor the R4140 These steps are included in the procedure:
1 Remove the flame detector leadwire from terminal F
on the subbase
2 Set the timer switch to TEST position and stop the programmer near the end of the Prepurge period
3 Plug the probe of the flame simulator into the tip jack
on the front of fhe programmer chassis (Fig 47) (The tip jack is connected direCtly to the F terminal of the programmer.)
4 Hold the plug (lead end) 01 the simulator against the programmer chassis The flame relay 2K should pull in
and stay in while the plug is in contact with the chassis
5 If relay 2K pulls in, the ampli1ieris okay (The trouble
is in the flame detector or its circuitry outside the programmer.)
6 If relay 2K does nol pull in, either the amplifier Of the programmer is faulty Replace the amplifier ,and check out the new one with the flame simulator
7 If relay 2K now pulls in, the old amplifier was fauny.11 2K still does not pull In, the programmer is faUlty
To check a standard R7248A Infrared Amplifier, use a la-inch length or insulated wire instead of a flame simulator Remove 3/4 inch of insulation 1rom each end of the wire Remove the plug-in amplifier, and plug one end of the wire into the tip jack on the front of the programmer chassis (Fig 48) Reinstall the plug-in amplifier,_ and lollow the same procedure as for the R7247A and R7249Aamplifiers:;' exceptl felf simulating flame (steps 3 and 4) To simulate llame, tap the free end of the wire against the programmer chassis about 2 times a second Relay 2K should pull in and stay in while flame is simutated CHECKING OUT THE SELF-CHECKING AMPLIFIER The R72478 or C or R72488 amplifiers with sel1-checking circuitry can be checked by observing the red 1lame-indicating larrp for these conditions:
R72478 or C DYNAMIC SELF CHECK REcnFICATION AMPLIFIER (GREEN)
No flame -lalTll should glow slightly Replace the amplilier ilthere is no glow, or if lhe larrp is ON (bright) conlinuously or blinking
Flame present -lamp should blink aboul 1 to 4 times a second Replace the amplifier if the larrp <::bes not blink
if the 1aJ'Tl) is ON continuously or blinking exces· sively (The 1aJ'Tl) may blink occasionally d.Je to electrical noise pulses on the signal leads These
occasional noise pulses are rejected by the ~Iifi
er and cb not affect normal c:peration.)
Flame present-lamp shoutd blink at the same rate thai
lhe flame Is fliCkering (as high as 20 limes a sec·
ond), Replace lhe ~Iifi&f if the lamp does nol blink
Trang 16TABLE V-FLAME SiGNAL
AMPUFIER
MINIMUM ACCEPTABLE STEADY CURRENT
(MICROAMPERES)
MAXIMUM CURRENT EXPECTED (MICROAMPERESI
Rectitjing Flame
Rod
R7247A (Grwn) R72476 (Green; Self Check) C
2
,.,/4
5'
2-1129 RectifYing
f:Ihclocell c
R7247A (Grwn) R7247B (Gillen: Self Oleck)c
2
HI4
5 b.g 2-1/2Q
(Purple Peeper)
C7012E F UltravDlet
a This minrnLm or s1Tonger signal should easily be obtained if the deleclDl' is COIT8CtIy instaJJad and positioned Ie sense trame property This current roWS be obtained befOre comcle1i!')(l ctJeckout,
b [):l,:~ permit :siQllalIe, exceed 5 microamperes as it WQuld stnten proloc:en life Reduce signal bY cise of;.'o~cf: P.lates (apenure
C 11 using an R7241B or an R7248B, Circuitry te$'lS Ih& Il4me &ilJn , amphhQr at re:!l~ 150 times a minute during burner operation and shuts daWn the burner if the ~faile
d rr using an R7Z47C or an R7476A, circuitry tests aU electronic components in th8 flarne detection system (amplifier 8nd dlllec:or) 60 to
120 times a minute during burner operation and shuts down th8 burner i1ll'1e d8tection system fei!s
8 Shutter oP8ra!ion of lI1e C7012E or F or C1076A causes fluctuations in the current reading Read t!'le average stable current dis
re~arding 0'1;) paak5
f The lead sulfide Cells ere available in 4 ranges of sensitivity: 104662A (red marking) lowest 1046626 (yello rnark,n!j'} medium;
,04652C (~reen rnlij1(ltlg) high; 1D4662D /Whi1tt maHlinll), highest ~"silivity If a sufficiently strong signel canrol otherwise be obtlio&d, try a dilterent cell of the same range 11 necessary, sUb6lilute e ceM of hgher sensitMty,
g Flame currents in excess of 200 miCtoamps ma.y be measured on R7247 (green) amplifiers used wrth lI1e BC7000, This condition is
Cau~C1 by condenSoiloon Inside the BC7000 Chfl"i5 It mav occur if a cold BC700Q is mounled in a wam'l area This false llama re.aCling does rXJI arleet 1he perlorrnance at lI1e ,BC7000 or flame sensor and .ill claar Itse~ when the condensaoon dries out,
F-BC7(O) e
ANALYZING TIiE OPERATING SEQUENCE As a traininQ aid, each line is numbered along {'"Ie lefi 01
The awroach used in analyzing the operation of an relay contacts, which are referenced alonQ the riQhl of Ihe R4140 Flame safeguard PrO!;)ramming Control can be ap schemalic_ The line numbers for localing each set of relay
coil appears.
THE LADDER DIAGRAM (FIG_ 49)
The simplified schematic diagram found in lhe instruc Rel9u;ng 10 FiQ 49:
tion s.'leeI fOr anyprogram~ Is commQllly called a 'lac}
Relay 2K is in line 7, and the line locations for 2K cander diagram_· It gets this name because, where p:tSSib\e,
lacts (2K.14,.lll 8) are althe right end of line 7
il tollows the S8QJence of operation in step 10rm (rl,Jn~
Relay 1K is in line a, and the line :ocations for 1K confrom Ic:p 10 bollcm_ (The circulls controllinQ the timer and
tacts (1K,15, ~ 12) are allhe right end of line a.burfllilr molar are shown near Ihe bOttom of the tad:!er for
The LS HTR (lockout switch healer) Is In line 10, andconvenience in drawing lhe schematic lhey actually are
the line locations lor lockout switch contacts (LS-21,involved IhrouQhOu! lhe enli'e sequence, from startup
Trang 17, TIMER OIAL PL'FIER
PROGRAMMER CHASSIS FLAME SIMUL TOR
FIG 47-USING A FLAME SIMULATOR (FOR A
STANDARD R7247A RECTIFICATION AMPLIFIER OR R7249A ULTRA
VIOLET AMPLIFIER)
the lockout switch is not a retay, but it is convenient
, -.'
to reference it the same way.}
The line tocation nurri)ers for each set of retay contacts
are tisted in the orrJ", of the contact numbers Atso, an
und"rlin"d location number indicates a normally clos"d
contact (with thEt retay dEH3n~rgizedl-an others are nor·
mally open A ctosed contact is drawn with a slash through
it ('1'J, ) Referring to Fig 49:
2K line tocation numbers (14, ~ 8) indicare that~
- 2K1 is in line 14 and is normally open
- 2K2 is in line 10 and is normally closed
- 2l<J is in line 8 and is normally q:lElI1
lK line location numbers (15.ll 12) indicate thar
- 11<1 is in line 15 and is normally cpen
- 1K2 is in line 15 and is normally closed
- lK3 is in line 12 and is normally cpen
LS (lockout switch) line location numbers (21, W indi
cate lhal
- LS1 is in line 21 and is normally q:>en
- LS2 is in line 6 and is normally closed
The actual physical locations ot the relay contacts OIl this typical programmer are shown in Fig 50 Lockout switch contacts are inaccessible All instruction sheets show the location 01 relay contacts
Timer contacls are Indicated by an ~ M" preCeding the contact number The contact number is determined by its actual physical location in Ihe timer (Fig 51)
Whether the contact is an • A" or a - B" is determined
by its position (Fig 52) Inside contacts are labeled ~ A
PLUG·IN MPLIF'ER
FIG 46-SIMULATING FLAME FOR A STANDARD
R7246A INFRARED AMPLIFtER
and OUlslcre contacts are labeled" B." The cams are desiglElCl so ~A" contacts snap closec:t and -B- contacts
snap q:lElI1 (An easy way to remember this is ~ AC- and
~BO -lin designing the programmmer, snap action con
tacts are selected to make or break the circuit to an elecfri·
vices CfJame detector, limits, main fuel valve, etc.) are Indicated by dashed lines
Trang 18H., ,.IU IECOW OE GHATE ,'h'
1l41401li'1004/M101Z SC':'!lMATIC "'".<O~'
,"'TMiw,u'''U1 MIAY" DUTY COVUI "' " ,.V 6:::
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"" "" U Ul.T V'OLrJ "'-"", gUO,T"" ITH l<e'.cHlC"'NG HATU}l' 1'Ol"~ TO g~,v TKl ,N<JTT' " 0 TO l U 'N.C "
• , no"'NAc TKOOUGK AKlI.'OiTATl 'CM 'N TH, ~1">C
g.NA 1C SEC CHICK o 'm " U TD BCOCK "'AG
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& 'M ' O TK .' ' G , ""'cT, '''''"O 0 " T
11:: no.T '''n''LOt!<-II) Ii NOT ""'0,' ,,, Ii ''''-' 0
n ' ou ,.oMD' ON1H " ' ' ' ' ' " ••" " ,
& ""~ O'~.CT '''AIII( ''''''TID'' 0' CO ~ ~ TO A Be,,","
AGRA oF .'f.UI , O~ """""" OF 'G"'"o" A"O Oil vacv,