7500-S
ERIES
I
NSTALLATION
, O
PERATION
AND
S
ERVICE
M
ANUAL
130 of 143
19.3 Burner
PROBLEM
POSSIBLE CAUSE
SOLUTION
B
u
rner Fails to Start
Defecti
v
e On/Off or f
u
el transfer s
w
itch. Replace.
Control circ
u
it has an open control contact.
Check limits, proof of clos
u
re s
w
itch
and others as applica
b
le.
Bad f
u
se or s
w
itch open on in-coming po
w
er
so
u
rce.
Correct as req
u
ired.
Motor o
v
erloads tripped.
Reset and correct ca
u
se for trip o
u
t.
Flame safeg
u
ard control safety s
w
itch tripped o
u
t. Reset and determine ca
u
se for
apparent flame fail
u
re.
Loose connections or fa
u
lty
w
iring.
Tighten all terminal scre
w
s and
cons
u
lt
w
iring diagram f
u
rnished
w
ith the air t
u
rno
v
er
u
nit.
Frozen oil p
u
mp shaft pre
v
enting
b
lo
w
er motor
operation.
Replace oil p
u
mp.
Flame safeg
u
ard control starting circ
u
it
b
locked d
u
e
to flame relay
b
eing energized.
Possi
b
le defecti
v
e scanner -
replace.
Possi
b
le defecti
v
e amplifier -replace.
Scanner act
u
ally sighting flame d
u
e
to leaking f
u
el
v
al
v
e-correct
u
n
w
anted flame ca
u
se.
Defecti
v
e flame safeg
u
ard control -
replace.
Defecti
v
e
b
lo
w
er motor.
Repair or replace.
Occasional Locko
u
ts for No
Apparent Reason
Gas pilot ignition fail
u
re.
Refer to pilot adj
u
stment section
and readj
u
st to make certain that
ignition is instant and that flame sig-
nal readings are sta
b
le and a
b
o
v
e
minim
u
m
v
al
u
es. Use a manometer
or 0 to 10
w
c (24.9 m
b
ar) gas
press
u
re ga
u
ge on pilot test tee to
make certain that press
u
re is as
recommended.
Check for proper settings on direct spark oil ignition
electrodes.
Make certain that gap is not too
w
ide and that light-off oil press
u
re is
as recommended.
Gas pilot ignition and direct spark oil ignition.
Verify that there are no cracks in the
porcelain and that transformer end
and electrode end pl
u
g in connec-
tions are tight.
Loose or
b
roken
w
ires. Check
all
w
ire n
u
t connections and
tighten all terminal scre
w
connec-
tions in panel and else
w
here as
appropriate.
With flame safeg
u
ard controls that incorporate the
air flo
w
s
w
itch in the non-recycling circ
u
it,
ens
u
re that
w
hen main flame lights, the air flo
w
s
w
itch is not so critically set as to allo
w
occasional
momentary opening of the air s
w
itch contacts.
Содержание 7500 136
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Страница 33: ...SECTION 6 LIFTING AN AIR TURNOVER UNIT 21 of 143 FIGURE 10 Lifting an Air Turnover Unit Base Section...
Страница 36: ...7500 SERIES INSTALLATION OPERATION AND SERVICE MANUAL 24 of 143 FIGURE 12 Air Turnover Unit Sections Schematic...
Страница 67: ...SECTION14 ELECTRICAL 55 of 143 FIGURE 38 Wiring Diagram Key...
Страница 115: ...SECTION 15 SEQUENCE OF OPERATION 103 of 143 FIGURE 83 Wiring Subbase and Sequence Chart for RM7897 Burner Control Module...
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