Sterling SDFI, Installation And Maintenance Instructions Manual

Page: 21 / 36

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1. Install properly.
1. Prove the power source.
2. Tighten connections or
replace wiring.
3. If modulating voltages are
obtained, check TS114
circuit for shorts. Replace
TS114 if necessary.
4. If items B1-3 check out
and modulating voltages
are still not obtained,
amplifier may be assumed
faulty. Replace.
1. Replace modulator head if
not approximately 45-55
ohms for M611 Valve and
60-80 ohms for MR212
Valve.
2. Clean or replace plunger if
necessary.
1. Adjust to proper minimum
fire.
2. If reading is greater than
1.5" negative pressure,
check for clogged filters or
other inlet air restrictions.
Consult factory for other
solutions.
1. Correct wiring if shorts
exist.
2. If modulating voltages are
obtained, check TS114/
TS1007 for open circuits.
Replace TS114/TS1007.
3. Correct the wiring.
TROUBLESHOOTING GUIDE
Series 14 Discharge Temperature Control
Reproduced with permission from Maxitrol ® Company
Symptom Possible Cause Field Test Remedy
A. No Gas Flow.
B. Continuous
Low Fire
(Electronics
Problem).
C. Continuous
Low Fire
(Electronics
OK).
D. Incorrect
Minimum Fire
Erratic or
Pulsating
Flame.
E. Continuous
High Fire
(Electronics
Problem).
1. Arrow on side of valve
should point in direction of
gas flow.
1. Check for 24V AC at
amplifier terminals 7 & 8.
2. Inspect for loose or broken
wires between amplifier
terminals 1 & 2 and TD114
terminals 1 & 3.
3. Connect test resistor as
described in Preliminary
Circuit Analysis in Section
IX. Follow procedures
outlined.
4. Check items B1-3.
1. Measure resistance across
modulator terminals with
connecting wires detached.
2. Inspect. Plunger should be
installed to operate freely
in solenoid sleeve.
1. See valve adjustments in
Section IX.
2. Close main gas supply and
measure manifold
pressure with blower
operating. Reading should
be less than 1.5" w.c.
negative pressure.
1. Inspect for shorts at or
between Amplifier
terminals 1 & 2 or TD114
terminals 1 & 3.
2. Check TS114/TS1007 for
open internal circuit.
Connect test resistor as
described in Preliminary
Circuit Analysis. Follow
procedure outlined.
3. Inspect.
1. Modulating valve
improperly installed (or
see Symptom “L”).
1. Short circuit or no
voltage to the
amplifier.
2. Open circuit in TD114
Remote Temperature
Selector circuit or
wiring.
3. Short circuit in TS114
Discharge Air Sensor
circuit or wiring.
4. Faulty amplifier.
1. Short circuit or open
circuit in Modulator
Coil.
2. Plunger missing,
jammed or improperly
installed.
1. Incorrect by-pass
metering valve
adjustment.
2. Excessive negative
burner pressure.
1. Short circuit in TD114
Remote Temperature
Selector circuit or
wiring.
2. Open circuit in TS114/
TS1007 Discharge or
Inlet Air Sensor circuit
or wiring.
3. Jumper not connected
across amplifier
terminals 2 & 3.