Manitowoc help

[speargun]

please help
I have a manitowoc GD0602A ice machine. Ran fine until lightning surge came thru. Had to replace ice sensor bd., toggle switch, and contactor. Machine making ice ok but condenser fan will not shut off during harvest. Ice sensor bd. working properly,(nc #5 contact open during harvest but water pump delay not opening up until bin switch interrupts power supply at transformer. Then the water pump delay timer has 20 sec. delay and pump starts. I have also replaced water pump delay timer.
any help would be appriciated.

[IMSTIEN]

I would check the pressore switch for the condenser fan motor, brazed next to the high pressure switch.let me know i will show you an easy way to replace the pressure switch

[nike123]

Pages from ice.pdf

During harvest high pressure cut-out switch should be closed and contactor solenoid energized.
Ice sensor contacts 1-5 open and contactor 10-11 closed.
Check your wiring.

Also check again water pump delay relay wiring and (NO SCR switch) contacts 1-3 (contactor 11 and toggle switch 14) are "open".
If "closed" after 20 sec. you have faulty water pump delay relay.

Pages from ice2.pdf




That is the only 2 path of current where you could get energized fan motor. If above is OK you have miss wired wiring or some damaged insulation.

[IMSTIEN]

Check the fan cycle control contacts welded together internally during harvest cycle the head pressure drops consequently the fan cycle control switch should open since the switch does not open the contact cond fan motor does not stop.during harvest cut one of the wire from the fan cycle control and see if the fan motor shuts off. When it does cut the other wire and should not have any continuity at the fan cycle control

[nike123]

..........................Ignore!

[nike123]

Check the fan cycle control contacts welded together internally during harvest cycle the head pressure drops consequently the fan cycle control switch should open since the switch does not open the contact cond fan motor does not stop.during harvest cut one of the wire from the fan cycle control and see if the fan motor shuts off. When it does cut the other wire and should not have any continuity at the fan cycle control

Since contact# 19 is always energized and contact #11 state depend on functioning of water pump relay, contactor contacts 10-11 and ice sensor contacts 1-5, it is obvious that, in this case, fan cycle control doesn't matter.
In harvest cycle contact# 11 should be deenergized (check bolded lines at diagram) and therefore state of fan cycle control doesn't matter.

[IMSTIEN]

After reviewing the schematic during harverst contacts#1&5 should open to turn the cond fan motor off,check wiring

[IMSTIEN]

Hi nike123,
i beg to differ on contacts #11 it does not open during harvest cycle. Contacts #11&10 opens when contactor is de-energized thru 7 sec scr time delay so the water pump and the cond fan motor don't run when the bin is full of ice and the compressor is de-energized.

[nike123]

Hi nike123,
i beg to differ on contacts #11 it does not open during harvest cycle. Contacts #11&10 opens when contactor is de-energized thru 7 sec scr time delay so the water pump and the cond fan motor don't run when the bin is full of ice and the compressor is de-energized.

I didn't said that contacts 10-11 are open during harvest. I said that contact 11 should not be energized.

Pages from ice.pdf

During harvest high pressure cut-out switch should be closed and contactor solenoid energized.
Ice sensor contacts 1-5 open and contactor 10-11 closed.

If ice sensor contacts 1-5 are open, than contact 11 could not be energized thru closed contactor contacts 10-11

In harvest cycle contact# 11 should be deenergized (check bolded lines at diagram) and therefore state of fan cycle control doesn't matter.

By energized contact I mean it should be at neutral or line voltage depending on plug orientation.
If neutral is at L2 than it should be at line voltage.
If that plug is between two phase voltages, like in some countries, than we cannot tell that is L2 neutral and therefore my term "energized".

[speargun]

I will replace water pump timer again. Not opening up when machine goes into harvest.

[IMSTIEN]

Water pumps stays on thru contacts#1&3 during harvest cycle, coz the dump valve is energized to remove impurities, check wiring

[IMSTIEN]

Replacing the water pump timer will not resolve the initial cond fan not shutting off in the harvest cycle , check cond fan motor wiring make sure one leg of the cond fan motor is connected on terminal#11

[FowlCommander87]

I have the same exact ice machine as the original poster, the Manitowoc GD0602A, and am having a somewhat similar problem that I could use some insight/help on.

The machine was given to me with a fried Ice Sensor circuit board and the wiring to the evap. fan motor damaged, corroded through in one spot. I have since fixed the one spot where the wire to the evap. fan motor was broken and replaced the ice sensor circuit board, carefully marking and reconnecting each wire. When I switched the machine back on, the compressor, evap. fan, and water pump kicked on momentarily and then I immediately heard a loud pop. It again fried both the wiring to the evap. fan motor(in a different location than previously) and the new ice sensor circuit board( in the same exact location as previously). Both the original and new ice sensor circuit board got fried in the same exact spot as what looks to be a "mini contactor" with a clear cover towards the bottom right of the circuit board. Upon further inspection, it seems as the insulation on the wiring to the evap. fan motor was beginning to degrade and crumble over about a 2 foot section. I have since replaced that section of wiring that I am hoping was the cause of the problems. The evap. fan motor and water pump work like normal when connected directly. Even after the 2nd fried circuit board, the compressor still starts normally and chills the evaporator plate very quickly, just no evap. fan motor and no water pump due to fried circuit board. Before I fry a 3rd circuit board, I wanted to check to see if you guys think that the degraded wiring to evap. fan motor was the cause of the 2 fried circuit boards or do you think I have other issues.( i.e. bad water pump delay timer, fan control switch, etc.?)

Thanks to anyone that can provide some additional insight/ ideas/ or advice.