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a)
Freeze Cycle Diagnosis
: Confirm Comp, FMRs, and PM continue. Confirm that
LLVs energize. Next, confirm HGVs and X10 relay de-energize. During the first
5 min. of freeze, confirm evaporator is cooling. If not, confirm WV de-energized (not
leaking by), HGVs de-energized (not bypassing), LLVs energizes, TXV and HM
operate correctly, Comp is efficient, and refrigerant charge is correct. See "VIII.A.
Specification and Performance Data Sheets."
b)
Comp and FMRs Diagnosis
: If Comp and FMRs de-energize once freeze begins,
check that appliance has not shut off on HPS or DLT ("POWER OK" LED off).
If so, check "3)b) HPS Diagnosis" or "3)c) DLT Diagnosis" above. If CB "POWER
OK" LED is on (KMS), check for 115VAC at CB K1 #9 (V) to neutral (W). If 115VAC
is not present and LED 1 is on, replace CB. If 115VAC is present, check for 115VAC
at MC coil (SRK). If 115VAC is not present, check wire harness connections. Next,
check for 115VAC at MC coil. If 115VAC is present, check MC coil and contacts
continuity. Replace as needed. If MC is okay, check Comp start relay and start and
run capacitors (single phase). Next, check Comp motor winding continuity. If Comp
is energized but evaporator is not cooling, check for an inefficient Comp. See "VIII.A.
Specification and Performance Data Sheets."
FMRs Diagnosis:
If Comp is energized but FMRs are not, check for 115VAC at
MC terminal "NO" black (BK) wire to neutral (W). If 115VAC is not present, and
MC is energized replace MC. If 115VAC is present, check FMRs capacitors, motor
windings, and fan blades for binding.
c)
WV and HGVs Diagnosis
: If WV is energized, check for 115VAC at CB K1 #6 (O)
to neutral (W). If 115VAC is present after PM energizes in harvest cycle, replace
CB. If 115VAC is not present, replace WV (bypassing). If HGVs (KMS and SRK) did
not de-energize at the end of harvest, check for 115VAC at CB K1 #2 (P) to neutral
(W). If 115VAC is present 50 sec. after PM energizes, replace CB. If 115VAC is not
present, replace HGV(s) (bypassing).
d)
PM Diagnosis
: Confirm water is flowing over evaporator from PM and not WV.
If PM de-energizes once freeze begins (except for anti-slush), check for 115VAC
at CB K1 #4 (R) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is
present and PM is de-energized, check for 115VAC at control switch #5 (W/R) to
neutral (W). If 115VAC is present at CB K1 #6 (R) and not at control switch #5 (W/R),
check control switch continuity between #5 (W/R) and #6 (R). Replace as needed.
If 115VAC is present at control switch #5 (W/R) to neutral (W), check PM capacitor
and motor winding continuity.
e)
LLVs Diagnosis
: If LLVs does not energize, check for 115VAC at CB K1 #3 (BK) to
neutral (W). If 115VAC is not present, replace CB. If 115VAC is present, check coil
voltage and continuity.
f)
Refrigerant Pressures, HM, and TXV Diagnosis
: If evaporator is still not cooling,
check refrigerant pressures. See "VIII.A. Specification and Performance Data
Sheets." Next, check HM operation. If refrigeration pressures are above HM setpoint
and HM is bypassing, replace HM. Check TXV for proper operation. Remove TXV
bulb and hold it in your hand, refrigerant low-side pressure should rise, place
TXV bulb in ice water, refrigerant low-side pressure should drop. A 10 to 15 pound
pressure swing between warm and cold conditions indicate a good TXV. If a 10 to 15
pound swing is not present, replace TXV.
