Service Manual

21
5a) Initial Harvest Cycle – LEDs 1, 4, and 2 are on. WV and X11 relay continue. Comp,
FM* (if connected to CB K1 connector pin #9), FMR, HGV, and X10 relay energize.
CBmonitors the warming of the evaporator via the thermistor located on the suction
line. When the thermistor reaches 48°F (9°C), CB reads 3.9 kΩ from the thermistor
and turns harvest termination over to the harvest timer (S4 dip switch 1 & 2 and S5dip
switch 4). WV and X11 relay are energized during harvest for a maximum of 6 min. or
the length of harvest minus HPT setting (S4 dip switch 6), whichever is shorter. See
step 5b below.
a) Comp Diagnosis: Check that evaporator is warming. Ifnot, conrm that Comp
energizes. If not, check for 115VAC at CB K1 #1 (V) or #9 (V) to neutral (W).
If115VAC is not present, check for 115VAC at CB K1 #7 (BR) or #10 (BR) to neutral
(W). If115VAC is present at #7 (BR) or #10 (BR) and not at #1 (V) or #9 (V), replace
CB. If 115VAC is present, check for 115VAC at CR or MC solenoid. If 115VAC is
present, conrm contacts are closed. If not, replace CR or MC. If CR or MC contacts
are closed, check Comp external overload, Comp start and run capacitors, Comp
start relay, and Comp motor winding.
b) HGV Diagnosis: If Comp is energized and evaporator is not warming, check that
HGV energizes and opens. Check for 115VAC at CB K1 #2 (P) to neutral (W).
If115VAC is not present and LED 2 is on, replace CB. If 115VAC is present, check for
115VAC at HGV coil and check HGV coil continuity. Replace as needed.
c) LLV Diagnosis: Conrm that LLV is de-energized and closed (not bypassing).
Ifenergized, replace CB. If de-energized and bypassing, replace LLV.
d) FM* Diagnosis (if connected to CB K1 connector pin #9):
KM-1301SAJ3: Check that FM* is energized and fan blades are turning. If not, check
FM* capacitor, motor winding, and fan blade for binding. Note: FM* is energized at
full speed RPMs (1600) during the harvest cycle and only capable of 1 speed.
KM-1601SAJ/3: Check that FM* is energized and fan blades are turning. If not, check
FM capacitor, motor winding, and fan blade for binding. Note: KM-1601SAJ/3 FM* is
capable of 2speeds and is energized at slower RPMs (700) during the harvest cycle
through the fan speed control pressure switch. If FM* is operating at high-speed
RPMs (1600) during the harvest cycle, check condition of the fan speed control
pressure switch.
When open, head pressure <190 +- 10 PSIG RPMs at 700.
When closed, head pressure >250 +- 10 PSIG RPMs at 1600.
e) WRV Diagnosis: Conrm WRV is not leaking by. If WRV is leaking by, conrm HGV
is open and LLV is closed. Next, check for proper refrigerant pressures. If refrigerant
pressures are correct, adjust or replace WRV. See "IV.C. Water Regulating Valve
Adjustment (water-cooled models)."