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ArthurLeigh
25-08-2008, 11:35 AM
I have a fault with an N26 Nice Ice ice maker. On switching on, the green light comes on, the tray turns down and empties and then returns, the water enters and the stirrer starts, then the compressor, all normal so far. The evaporator starts to cool, the hot gas outlet of the solenoid valve remains cool and then ice forms on the evaporator as expected, however the defrost cycle starts when the ice thimbles are only about 1mm thick. The tray turns down and empties and then returns, the water enters and the stirrer starts, then the compressor, however the evaporator does not cool, the hot gas outlet of the solenoid valve remains hot.

It would appear that the solenoid valve is sticking in the defrost position. The resistance of the solenoid windings is about 5k and the solenoid when removed from the machine and powered from the 240V supply, attracts a screwdriver sufficiently to draw it inside and when the screwdriver is held, the weight of the solenoid is supported. So maybe the core of the solenoid is sticking or there are shorted turns in the solenoid, reducing its power. What should the resistance of the solenoid be, please? The refrigerant pressure switch operates about once a minute, turning on the condenser fan as expected, however each time this happens, there is a pulse on the solenoid which could cause it to turn on and let hot gas into the evaporator.

Do you have any suggestions, please?

:)By the way...

I electrically bypassed the pressure switch so now the condenser fan runs all the time except in the defrost cycle. The ice maker now works properly, so either the pressure switch was faulty or the system was slightly short of refrigerant.

I am still interested in further service information in case more faults develop.

Refcol
15-09-2008, 11:04 PM
I have a fault with an N26 Nice Ice ice maker. On switching on, the green light comes on, the tray turns down and empties and then returns, the water enters and the stirrer starts, then the compressor, all normal so far. The evaporator starts to cool, the hot gas outlet of the solenoid valve remains cool and then ice forms on the evaporator as expected, however the defrost cycle starts when the ice thimbles are only about 1mm thick. The tray turns down and empties and then returns, the water enters and the stirrer starts, then the compressor, however the evaporator does not cool, the hot gas outlet of the solenoid valve remains hot.

It would appear that the solenoid valve is sticking in the defrost position. The resistance of the solenoid windings is about 5k and the solenoid when removed from the machine and powered from the 240V supply, attracts a screwdriver sufficiently to draw it inside and when the screwdriver is held, the weight of the solenoid is supported. So maybe the core of the solenoid is sticking or there are shorted turns in the solenoid, reducing its power. What should the resistance of the solenoid be, please? The refrigerant pressure switch operates about once a minute, turning on the condenser fan as expected, however each time this happens, there is a pulse on the solenoid which could cause it to turn on and let hot gas into the evaporator.

Do you have any suggestions, please?

:)By the way...

I electrically bypassed the pressure switch so now the condenser fan runs all the time except in the defrost cycle. The ice maker now works properly, so either the pressure switch was faulty or the system was slightly short of refrigerant.

I am still interested in further service information in case more faults develop.
I had similar probs with a POLAR ice maker, bypassed the HP switchand all fine until the ambient conditions altered and caused overcondensing, so added a sniff of refrigerant.

welsh__boy
08-10-2008, 12:02 PM
We've got a Polar T318 in our workshop, been there for a while. Tray fills with water, then empties straight away. Changhed every probe, PCB at the rear, bypassed the pressure switch and still the same problem, the 'helpline' on the badge is useless, just people on the end of the phone with a spare parts diagram, anybody got any suggestions??? Please helpme!!

opt
14-10-2008, 11:48 AM
we where having a similar issue, we where playing with the water level probes and solenoid for a while, after not having much luck we stripped it and all the silicone which was holding the evaporator to the cold plate was all dissolved and nothing was attaching the evap to the cold plate and most of it was loose, which is why the ice was only good in some areas. I made up some metal brackets to hold the evap alot better onto the ice plate and applied some drip tape over it just have to weld it back into the system. Fingers crossed this was our problem.

ArthurLeigh
25-10-2008, 10:49 AM
We've got a Polar T318 in our workshop, been there for a while. Tray fills with water, then empties straight away. Changhed every probe, PCB at the rear, bypassed the pressure switch and still the same problem, the 'helpline' on the badge is useless, just people on the end of the phone with a spare parts diagram, anybody got any suggestions??? Please helpme!!

If the design is similar to the Nice Ice models, if the paddles stop turning, this indicates that the evaporator compartment is full of ice, the magnet on the paddle spindle activates the Hall effect switch and so pulses are sent to the processor all the time the paddles are rotating.

When the pulses stop, (or perhaps even if they slow down too much) the processor starts the emptying of the tray and the solenoid valve is energised which diverts hot gas to the evaporator, releasing the ice.

You need to check that the paddles turn continuously and that the magnet is close enough (about 2 mm or closer, not too close or a buildup of scale on or near the magnet might prevent the paddles from turning. If you alter the spacing, which should only be necessary if the Hall Effect switch or other rotation detector is loose, you should make a note of it before altering it, in case that is not the problem!) You can also check for pulses to the processor. If this does not appear to be the problem, you can switch off the machine and try disconnecting the electricity supply to the tilting motor and to the solenoid, if there are no other faults, the machine should make ice when you switch on again.

If the machine then makes ice, before you restore the connections you need to pay particular attention to the ice detection mechanism (rotating paddles, the cables and connectors etc), you need to switch off again, check the resistance of each connector and cable between the ice connection mechanism and the processor, with a multimeter. If any of the electronics uses CMOS technology, you should of course temporarily earth yourself by briefly touching an earthed object to discharge static electricity, before touching the conducting parts of leads or components on the board.

I hope this is of some help.