Bradford White U2TW75T*RN, Руководство по обслуживанию

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Steady State Operation.
D u rin g Steady State Operation t h e C ontrol Monitor s :
Ther m ostat te m perature sensor - Wh en s et point te m perat u re i s s ati sf ied , g a s v al v e i s shu t do w n and
b lo w er w ill po s t p u r g e f or 1 5 s e c ond s . C ontrol L E D f la sh e s a sh ort f la sh on c e e v ery 4 s e c ond s (idle) s tat us
c ode.
P ressure switch / Bl ower te m perature switch - I f eit h er sw it ch open s, pilot v al v e and m ain v al v e i s shu t
do w n. Th e b lo w er c ontin u e s to r u n s f or 30 s e c ond s atte m ptin g to c lo s e t h e c ir cu it. Th e c ontrol L E D Fla sh e s
3 times
w it h 3 s e c ond pa us e.
Fl a m e Sensor - I f f la m e i s lo s t , pilot & m ain v al v e are shu t do w n , b lo w er r u n s f or 1 5 s e c ond s . C ontrol atte m pt s
to re-li gh t pilot 4 ti m e s . I f u n succ e ssfu l , B lo w er i s shu t do w n and c ontrol pro c eed s to 5 m in u te lo c ko u t. C ontrol
re-atte m pt s to li gh t pilot s tartin g at nor m al h eatin g s e q u en c e # 2 .
Th er m o s tat Sati sf ie s .
Bu rner O ff .
B lo w er P o s t Pu r g e (1 5 s e c ond s) .
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Se q uence o f O peration
Ab nor m al Operation
1 . Si mu lated R e s i s ti v e De v i c e Fa u lt:
a ) If the resistance is g reater than 70,000 O h m s - t h e g a s c ontrol i mm ediately t u rn s o ff all o u tp u t s . C ontrol w ait s
and m onitor s re s i s tan c e f or 30 s e c ond s . I f t h e re s i s tan c e i s g reater t h an 70 , 000 o hms a f ter 30 s e c ond s, t h e
g a s c ontrol pro c eed s to v eri f y re s i s ti v e delay f or 2 m in u te s and f la sh e s
8 times then once
w it h a t h ree s e c ond
pa us e. Th i s pro c e ss i s repeated 5 ti m e s u ntil t h e c ontrol eit h er ret u rn s to nor m al operation or pro c eed s to f la sh in g
7 times
w it h a 3 s e c ond pa us e.
b) If the resistance is b e l ow 3000 oh m s - Th e g a s c ontrol i mm ediately t u rn s o ff all o u tp u t s and pro c eed s to f la sh
8 times then once
w it h t h ree s e c ond pa us e. Th e error s el f c lear s i f t h e re s i s tan c e ret u rn s to nor m al ran g e f or at
lea s t 1 5 s e c ond s .
Nor m al H eatin g Se qu en c e (c ont. )
2 . T e m perat u re Sen s or Fa u lt:
a ) Te m perature sensor d etecte d open circuit - Th e g a s c ontrol I mm ediately t u rn s o ff all o u tp u t s and pro c eed s to
f la sh
8 times then twice
w it h t h ree s e c ond pa us e. Th e error s el f c lear s i f t h e f a u lt c lear s f or at lea s t 1 5 s e c ond s .
b) Te m perature sensors not rea d in g the sa m e te m perature within ±5.5 °F - Th e g a s c ontrol I mm ediately t u rn s o ff
all o u tp u t s and pro c eed s to f la sh
8 times then three times
w it h t h ree s e c ond pa us e. Th e error s el f c lear s i f t h e f a u lt
c lear s f or at lea s t 1 5 s e c ond s .
c) W ater te m perature in e x cess o f ECO (E ner gy C ut O ut ) l i m it - Th e g a s c ontrol i mm ediately t u rn s o ff pilot &
m ain v al v e and pro c eed s to f la sh
4 times
w it h 3 s e c ond pa us e. B lo w er c ontin u e s to r u n u ntil g a s c ontrol i s re s et.
Th e s et point kno b sh o u ld b e t u rned to t h e m ini mum te m perat u re s ettin g f or at lea s t 6 s e c ond s and t h en t u rned
c lo c k w i s e b y at lea s t 45
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