Sterling SDFI, Инструкция по установке и обслуживанию, Страница: 24 / 36

– 24 –
TROUBLESHOOTING GUIDE TROUBLESHOOTING GUIDE
Series 44 Room Temperature Control
Reproduced with permission from Maxitrol ® Company
Symptom Possible Cause Field Test Remedy
1. Valve improperly
installed.
1. Open circuit in
modulator coil.
2. Plunger missing,
jammed or improperly
installed.
3. Ruptured main or
balancing diaphragm.
1. No voltage to the
amplifier.
2. Short in modulator coil
circuit.
3. Short in TS144 circuit.
4. Faulty amplifier.
1. Incorrect by-pass
metering valve
adjustment.
2. Excessive negative
burner pressure.
1. Install properly.
1. If proper resistance values
are not observed, replace
modulator head or repair
wiring.
2. Clean or replace plunger if
necessary.
3. Replace diaphragm if
ruptured.
1. Provide 24V AC to
amplifier. Refer to item K1.
2. If proper resistance values
are not observed, replace
the modulator head or
repair wiring.
3. If readings are incorrect,
replace the TS144 or
repair wiring.
4. If power source and
modulator coil check out
(items 5 & 6) but proper
modulating voltages
cannot be obtained, then
amplifier may be assumed
at fault. Install replacement
amplifier.
1. Adjust to proper low fire.
2. If greater than 1.5"
negative pressure, check
equipment for clogged
filters and other inlet air
restrictions. For other
solutions, consult factory.
1. Arrow on side of valve
should point in direction of
gas flow.
1. Remove wires connected
to amplifier terminals 6 & 7
and measure resistance.
MR212 (60-80 ohms),
M611 (45-55 ohms).
2. Inspect - plunger should be
installed to operate freely
in solenoid sleeve.
3. Disassemble valve for
inspection of internal parts.
1. Check for 24V AC at
amplifier terminals 8 & 9.
2. Measure resistance per
item B1.
3. Remove wires connected
to amplifier terminals 1, 2 &
3. Measure resistance
across wires 1 & 3, then 2
& 3. Meter should read
greater than 2500 ohms.
4. Follow procedures outlined
in “Preliminary Circuit
Analysis” in Section IX.
1. See Valve Adjustments -
Section IX.
2. Close main gas supply and
measure manifold
pressure with blower
operating. Should be less
than 1.5" w.c. negative
pressure.
A. No Gas Flow.
B. Continuous
Low Fire
(Electronics
OK).
C. Continuous
Low Fire
(Electronics
Problem).
D. Incorrect Low
Fire.
Control circuits external to Series 44 can cause burner malfunction.
Always check manual valve to be certain gas is on, and check limit controls for normal operation.