Service Manual

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4) Initial Harvest Cycle – LEDs 1, 4, and 2 are on. WV and X11 relay remain energized,
Comp, FMR, HGVs, 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 a 3.9kΩ signal from the thermistor and turns harvest termination over
totheharvesttimer(S4dipswitch1&2).Fordetails,see"II.C.3.b)HarvestTimer
(S4dipswitch1&2)."Thepump-outtimer(S4dipswitch3&4)actsinplaceofthe
harvesttimerduringcycleswithapump-out.Fordetails,see"II.C.3.c)Pump-OutTimer
(S4dip switch 3 & 4). WV and X11 relay are 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. 50seconds before the harvest timer terminates, LED
4turns off, WV and X11 relay de-energize.
Harvest Pump Timer: LEDs 1,3, and 2 are on. LED 3 turns on and PM energizes
through CB K1connector pin #5 (DBUwire) and X10 relay for the last 50seconds of
harvest. Comp, FMRs, and HGVs remain energized. 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. When the harvest timer terminates, the
harvest cycle is complete. CB checks the position of F/S and proceeds to the next cycle
if it is closed, or calls for a 1-minute ll cycle if it is open. The minimum total time allowed
by CB for a complete harvest cycle is 2 minutes.
Diagnosis: Check that Comp, FMR, HGVs, and X10 relay energize. 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, HGVs are
energized and open, LLVs are de-energized and closed. Conrm proper unit pressures.
Place a thermometer on the suction line next to the thermistor. Has it warmed to 48°F
(9°C) or warmer? If temperature has been reached, check that WV and X11 relay
de-energize (LED 4 off). If temperature has been reached, but WV and X11 do not
de-energize,checkthethermistor.See"IV.E.ThermistorCheck."
Harvest Pump Timer: PM energizes (LED 3 on) last 50 seconds of harvest. If not,
make sure CB S4dip switch 7 is in the factory default position. Check for 115VAC at
CBK1connector pin #5 (DBU wire) to a neutral (W wire). If 115VAC is not present and
LED 3 is on, replace CB. Next, check for 115VAC at X10 relay terminal #4 and terminal
#6to a neutral (W wire). If 115VAC is present on terminal #6 (DBU wire) and not on
terminal #4(Rwire), X10 relay is de-energized or bad. If 1-minute ll 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.