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AP LCM4


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I have an AP LCM4 that is not cooling properly. I think part of the issue is that the customer keeps placing the machine against the wall. I looked at it today and the drinks were cool but not warm or cold. The filter is clean and the compressor was working. It turned off and the thermostat setting was maxed out. Turning it off and on yielded no results. I did notice a big block of ice in the can dispensers. My question is, once the ice thaws and I can keep proper clearance from the wall will the unit work properly again or am I looking at a low refrigerant issue that caused the machine to freeze up in the first place? Can the referigant be added if it's low or do I need to replace the unit? Sorry for being so long winded.

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The machines should always be 4-6 inches from the wall for proper air flow over the compressor unit. Being up against the wall could have caused it to overheat and there-by damaging the unit. Since the evaporator coil was frozen, check to be sure that the fans behind the coil are turning freely.

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Thanks for the reply. Is replacing this unit as troublesome as it looks? I've replaced compressor units in drink machines but never in a combo unit. I look at it and do not know where to begin when it comes to removing the unit.

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The things to check for on an LCM4 is space behind the machine (most vendors have never used the air deflector from AP that holds it away from the wall), make sure the air filter screen under the cabinet is clean (removable from in front of the can module), make sure after it's defrosted that the fan inside the can module is running (if it's not then you might have had a can fall from the rack onto the fan blade or the fan motor is bad), that water is draining completely from the module and that no delivery doors are held open by poorly timed/ broken vend motors.  You should also make sure the defrost timer is working (found next to the thermostat) and that the thermostat is unmolested (it's not designed to be adjusted - that's why there is a plug on the hole to it.  If these things are all fine and the machine either won't cool or freezes the evaporator again then you are low on freon.  You can remove the rear screen to access the compressor for recharging by a certified refrigeration tech. 

 

If you ever have to get to the compressor for a replacement or to repair a leak then you must empty the can module and remove it completely from the machine.  Then you have to remove the can module from the cooling base to actually work on the cooling unit.  This is usually a job for an experienced tech.  I've done many of them and they are a pain in the butt to get apart and back together by yourself.

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AZVendor, if I understand your post correctly. A tech can recharge the compressor by accessing the back panel. Is this a correct assumption. Also I could not hear the thermostat disengage or engage when I attempted to turn it off and on. Is this due to the ice build up in the machine?

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Yes, it can be recharged from the rear by installing a line tap on the low side stub off the compressor.  There may be a Schrader valve on it already if the compressor has ever been replaced or a tap from a previous recharge.  Because of the ice, the thermostat would not be at a temperature that would allow it to turn off.  I would also suspect you have a bad defrost thermostat since it's designed to bypass the thermostat and turn the compressor off so that any frost on it can melt.  This is done two to four times per day (I can't remember how often this occurs) and it's not adjustable.  The only reason you can remove the plug and get to the round plastic actuator of the defrost timer is so that you can test it by turning it until a defrost cycle starts and see if the machine behaves accordingly.  If it doesn't turn the compressor off for at least 15 minutes then it should be replaced.  There is a chance that this is what caused the ice to some extent but usually a block of ice that large is caused by a non-functioning evaporator fan or low freon.

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It is very common for these to freeze up for several reasons as AZ has mentioned. Bad thing about these cold controls are $75 och!

 

My fix was to purchase a Electronic Temperature control for about the same amount of money.

 

etc-111000-000-3.jpg

 

It is a little bit of a challenge to wire in but well worth it. You can set the temp for 36 Degrees and then set the temp for when you want it to come back on. In my case I would set 36 to 46 degrees. I drilled a hole where the probe can be laid in front of evaporator but not touching it. When it is hot the compressors run to often not allowing the condensation to fall of evaporator thus you get a freeze up. To simplify installation I wired the evaporator fan to cycle with compressor. Less wires to have to figure out.

 

You are dealing with air temp not product temp so cut off is 36 degrees that is where your product temp will be when compressor shuts off. Product temp won't move much before the compressor comes back on. Product at top might be a little warmer than the bottom but it should be ok.

I have used these temp controls for several applications to stop freeze ups and they have worked very well. Have installed them on National 430's and DN 5591's with great success.   

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I have an AP LCM4 that is not cooling properly. I think part of the issue is that the customer keeps placing the machine against the wall. I looked at it today and the drinks were cool but not warm or cold. The filter is clean and the compressor was working. It turned off and the thermostat setting was maxed out. Turning it off and on yielded no results. I did notice a big block of ice in the can dispensers. My question is, once the ice thaws and I can keep proper clearance from the wall will the unit work properly again or am I looking at a low refrigerant issue that caused the machine to freeze up in the first place? Can the referigant be added if it's low or do I need to replace the unit? Sorry for being so long winded.

Cut a 2x4 to length a place it behind the legs of the machine - this will ensure that the machine can't be pushed flush to the wall.

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No there isn't.  To empty the can selections you must set them to a zero price so that you can then enter the selection number on the door to vend them out one at a time.  However, this won't give you access to the cans that have fallen. To do that you have to remove the front door of the module (the entire door frame) by removing the screws under the candy shelf.  Then tilt and lift the door off the bottom channel, but be careful as years of soda leakage will cause the door gasket to stick to the module and tear off if you're not careful.  If the gasket is stuck you can tilt the top of the door toward you and use a flat blade screw driver to pry the lower edge of the gasket away from the module, inch by inch.  It might still be stuck to the bottom door channel though so continue taking care when removing the door.

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My bet is the coils are full of dirt and dust after 20 years of operation.

 

It is a pain in the back side but at this point the only real option is to pull the unit out, clean the coils, check and replace any bad fans and check it on the bench if it is not cooling correctly then find and fix the leak.

 

 

Walta

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 I would also suspect you have a bad defrost thermostat since it's designed to bypass the thermostat and turn the compressor off so that any frost on it can melt.  This is done two to four times per day (I can't remember how often this occurs) and it's not adjustable.  The only reason you can remove the plug and get to the round plastic actuator of the defrost timer is so that you can test it by turning it until a defrost cycle starts and see if the machine behaves accordingly.  If it doesn't turn the compressor off for at least 15 minutes then it should be replaced.  There is a chance that this is what caused the ice to some extent but usually a block of ice that large is caused by a non-functioning evaporator fan or low freon.

 

 

There were 2 different Defrost timers used on the LCM

 

One would defrost 6 minutes every hour the other would defrost for 20 minutes every 6 hours

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