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4) Initial Harvest Cycle – LEDs 1, 4, and 2 are on. Comp, FMRs, HGVs, X10 relay, WV2,
X12, and X13 relays energize. WV1 de-energizes. 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). The harvest timer has settings of 60, 90, 120,
and 180 seconds. The pump-out timer (S4 dip switch 3 & 4) acts in place of the harvest
timer during cycles with a pump-out (S4 dip switch 5 & 6). WV2 and X12 relay are
energized during harvest for a maximum of 6 minutes or the length of harvest minus
50 seconds, whichever is shorter. 50 seconds before the harvest timer terminates,
harvest pump timer starts. LED 4 turns off, WV2 and X12 relay de-energize.
Harvest Pump Timer – LEDs 1, 3, and 2 are on. Comp, FMRs, HGVs, and X10
relay continue. LED 4 turns off, WV2 and X12 relay de-energize (CB K1 connector pin
#6 (O wire)). LED 3 turns on and X11 relay energizes (CB K1 connector pin #5 (DBU
wire)), allowing PM to energize for the last 50 seconds of harvest (S4 dip switch 7
setting). NOTICE! S4 dip switch 7 must remain in the factory default position of
7 on. Otherwise, PM will not energize during the last 50 seconds of harvest. The
minimum total time allowed by CB for a complete harvest cycle is 2 minutes. At the end
of harvest, CB checks the position of F/S and proceeds to the next cycle if it is closed,
or calls for a 1-minute fill cycle if it is open.
Diagnosis: Check that evaporator is warming and Comp, FMRs, and HGVs remain
energized. WV2 is energized during harvest for a maximum of 6 minutes or the length
of harvest minus 50 seconds (Harvest Pump Timer (S4 dip switch 7)), whichever is
shorter. Average initial harvest cycle at factory setting is 2 to 3 minutes. 1.5 minutes after
initial harvest begins, touch Comp discharge line. Is it hot? If not, check that Comp is
energized, refrigerant pressures are in range, HGVs are energized and open, LLVs are
de-energized and closed. If discharge line is hot, place a thermometer on the suction
line next to the thermistor. Has it warmed to 48°F (9°C) or warmer? Confirm thermistor
status. See "IV.E. Thermistor Check." If temperature has been reached, check that
WV2 de-energizes (LED 4 off) and X11 relay energizes (LED 3 on), allowing PM to
energize and circulate water over the evaporator for the last 50 seconds of harvest. If
not, make sure S4 dip switch 7 is in the factory default position. Check CB K1 connector
pin #5 (DBU wire) and X11 relay for 115VAC. If 1-minute fill cycle starts after harvest,
see "IV.D. Float Switch Check and Cleaning." If the thermistor reading is in proper range
and CB fails to terminate the harvest cycle and initiate the freeze cycle, replace CB.
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