Service Guide

23
f) Comp and ConFM Diagnosis: Conrm Comp and ConFM energize. If not, check
for 115VAC at CM C1 (R or V) to neutral (W). If 115VAC is not present, check CTh
status. See "II.D.Thermistor Check." If CTh ohm reading is in proper range, replace
CM. If not in range, replace DTh. If115VAC is present at CM C1 (R or V) to neutral
(W), check for 115VAC at CR #0 (GY or P) to CR #1 (W). If 115VAC is not present,
check continuity of HPS. Ifopen, allow time for HPS to reset (cut out: 490 ±10 PSIG,
cut in: 370 ±20 PSIG). IfHPS does not reset, see "g) HPS Activation" below. IfHPS
is closed and 115VAC is present, check for 115VAC at CR #4 (BK) and CR #6(R) to
neutral (W). If115VAC is present at CR #4 (BK) and not at CR #6(R), replace CR.
If115VAC is present at CR #6 (R) to neutral (W) and ConFM is energized but Comp
is not: On 1-section; Give time for internal protector to cool and reset. Next, check
run capacitor, start capacitor, start relay, and Comp motor windings. If Comp does
not start, replace Comp. On 2-section; Check for 115VAC at Comp external protector
to neutral (W). If 115VAC is not present, give time for Comp external protector to
cool and reset. If Comp external protector does not reset, replace Comp external
protector. If115VAC is present, check run capacitor, start capacitor, start relay, and
Comp motor windings. If ConFM is not energized, check ConFM fan blades for
binding and motor winding continuity.
If Comp and ConFM are energized and the cabinet does not cool down, check for a
restriction in the refrigeration circuit, correct TXV operation, and correct refrigerant
charge. See nameplate for correct charge amount.
g) HPS Activation (cut out: 490 ±10 PSIG, cut in: 370 ±20 PSIG): Conrm ConFM
is energized and fan blade turns freely. Conrm condenser coil is not clogged or
restricted. Conrm there are no restrictions in the refrigeration circuit (TXV and drier).
Let refrigeration circuit pressures equalize. IfHPS does not reset and pressures
are equalized, replace HPS. If pressures are not equalized, reclaim refrigerant and
diagnose refrigeration circuit restriction.
8) Cool Down Achieved–Lights, DrH, EvapFM, MH, and PH continue. CTh cools to
3°F(1.7°C) below setpoint. Comp and ConFM de-energize.
a) Diagnosis: Conrm Comp and ConFM de-energize. If not, and Comp and ConFM
were energized longer than 2 min., check CTh status. See "II.D. Thermistor Check."
IfCTh ohm reading is in proper range:
b) CM Diagnosis: Check for 115VAC at CM C1 (R or V) to neutral (W). If115VAC is
present, replace CM.
c) Comp and ConFM Diagnosis: Check CR#6(R) to neutral (W). If 115VAC is present,
replace CR.