USI CB500 problem

[EddieMac]

I have several USI CB500 10 select drink machines.  Two of them experienced the same problem within two days of each other.

On both of them the evaporator fan (the bottom fan) quit working.  I swapped the first machine with a working machine, ordered two fan motors, then replaced the one on the first machine.  I let it sit in my warehouse running for a few days.  No problem.

Then I took it to the 2nd location and swapped it out for the other CB500 that quit.  (I have the motor for the 2nd one, but I haven't had time to replace it yet).  The 1st machine with the replaced fan motor did fine for the past several weeks until I got to it yesterday and found it frozen again.  I checked it out to find the same fan motor is not running!!

Any ideas what the problem is?  A bad replacement motor or is there something with the machine causing the motors to quit?

Thank you in advance for your time and expertise.  I've been vending for several years now, but I'm still learning.

[AngryChris]

First thing you need to know is that the bottom fan is the condenser fan.  The top fan (the one that is behind the evaporator, above the compressor and condenser) is the evaporator fan.  Secondly, having two fan motors go out sounds very odd.  One thing that is important to mention is that the condenser fan is supposed to run whenever the compressor runs... so if you have a bad thermostat for example, it could mistakenly tell your compressor NOT to run which will cause the condenser fan to not run.  The first thing I would do is verify that the old fan is good or bad (don't ask me how).  Then, I would check to see if the thermostat is bad.

When you say it's "frozen," do you mean the fan isn't working or do you mean the evaporator is frozen?  If you are saying that the evaporator is icing up (the part behind the delivery tray) then it could possibly be that you have a completely different problem.  If the evaporator is forming ice in one corner of the evaporator but not the whole thing, then chances are that your refrigeration deck is low on refrigerant which will cause ice to form on the evaporator AND the thermostat.  I have never changed a thermostat in a cb500 so I don't know if they are analog or digital thermostats.  If there is an actual thermostat down there and the ice is forming over the thermostat, the ice will make the thermostat think that the machine is cold which will prevent the compressor from running (because the thermostat says it's cold enough) and the condenser fan won't run either.

It's important to tell us exactly what's happening because I have a suspicion that whatever fan you replaced may have been fine but you had a different problem.

[AZVendor]

The fan under the machine in front of the compressor is the condenser fan.  The fan inside the machine behind the evaporator is the evaporator fan.  If the new fan that quit is a condenser fan then you probably have a loose wire that you didn't connect properly.  This won't cause a frozen evaporator though, just a short cycling compressor that won't cool the machine as it overheats.

If the fan is inside the cabinet then you again may not have connected the wires securely.  The other thing that can happen is that these fan motors are square body ECM motors and on the evaporator fan you must mount the motor to a bracket using the holes in the frame of the motor.  If you put too long a screw into the holes you will short out the winding in the motor and burn it up.  I can't remember if all the screws are the same length but this happened to me once when, as I recall, I replaced one of the 4 screws with one that was too long because I lost one of the four, and this killed the motor.

One other issue with the evaporators on those machines is to make sure you mount the motor and it's bracket correctly so that the fan blade doesn't hit anything and stop it.  Also make sure that none of the screws that mount the bracket or the rest of the evaporator shroud are stripped out and loose.  This can cause the fan blade to hit.  

 

Chris:  The CB500 and CB700 (or BC500/BC700 if sold under the FSI name) all have temperature sensors plugged into the logic boards, not thermostats.

[EddieMac]

When you say it's "frozen," do you mean the fan isn't working or do you mean the evaporator is frozen?  If you are saying that the evaporator is icing up (the part behind the delivery tray) then it could possibly be that you have a completely different problem.  

 

There is a massive amount of ice on the evaporator and the line going down to the condenser.  The ice stops where the lines go down into the bottom of the machine.   The condenser fan (sorry I typed the wrong one earlier) is not working even though the condenser is running and it hot.  It ran fine for a couple of months after I replaced the condenser fan motor, now the fan is not running at all.

I do still have the other CB500, that had the same problem, in my shop, and a new fan motor for it.  I may try to replace that one and swap the machines again until I can figure this out.  I can't do anything for a while though because we have a hurricane about to bear down on us which is going to put me way behind on servicing my accounts.

I don't know how long it was frozen this time as no one will call me when something happens even though my phone number is on the machine and I keep giving my business card to people there.  (But that's a totally different rant).

[AZVendor]

Hope all is well with you and that you come through the storm safely.  You won't be behind on your route because all of your locations with be closed too.  You might get behind though if they go back to work and you can't get to them.  Hopefully that won't be the case.

Just so you get your terminology right, the compressor is what you referred to as "running and hot," the condenser fan is in front of the compressor and behind the condenser (radiator-looking part).

Defrost the machine and check that the evaporator fan is running well afterward.  If it is then your ice means you are low on freon and the compressor needs to be recharged.

Also, your rant if valid.  You can put 15 phone numbers on a machine and you may never get a call about a problem.  I always loved it when more than one person called and thanked them all for it.