Fridge not cooling,compressor wont kick in

did you check the fan motor?
if so maybe compessor is bad?

I would think that the compressor is either overheating, or faulty and cutting out on a Thermal overload cut out device fitted to the compressor.
If it is overheating, then it could be due to several problems:
1] Ventilation to the compressor is poor, or blocked.
2] compressor Cooling fan failed ( not fitted on all models)
3] Condensor blocked ( Not fitted on all models) This looks like a small car radiator in the compessor compartment (if fitted?).
Turn the fridge off, and leave it for up to 2 hours to cool, once cool, ensure that the ventilation is good around the compressor compartment, and try it again. If it starts and runs as normal it may have just overheated. If there is a fan fitted in the compressor compartment, then observe if it is working or not when you turn it back on.
If the compressor cuts out again, as you have described, trhen it is more than likely that the compressor has failed and needs replacing.
This is not a job that a novice can do, and will be expensive to have replaced by a Refrigeration engineer.
I hope this helps?

I've never seen a comercial fridge with fans. I think you speak about the compessor. Assumed the fridge has power (iside light when you open the door) that means the thermostat is defective. Your fridge needs a new thermostat. It could be cheaper to buy a new one.

Where exactly is this fan located? Are you saying that if you spin it it does start to run? For how long? Tx, Petra

If it has fan to deliver cold air, and it is not working, cold air is stuck on the begining. So your fan could be dead. And I suppose, that compressor is running all the time. Even compressor could stert freezing if fan does not deliver cold air in fridge. The other option is, that there is not enough gas in the compressor. In this case compressor vould not be freezing, but line, going out of compressor has to be hot, if it is not, there is no gas.

No reset on compressor. Try controller first, and check all else working e.g. fans lights etc. if power to compressor and not running, time for a new compressor

Could be a couple of reasons for this:
1. Condensor fan motor bad.
2. Condensor fan motor loss of power.
3. Condensor fan motor capictor bad.

Unit has control for fan for low ambient operation and unit is low on freon telling fan its cold out side and dont run.
Hope this helps. wally

if the fan blade is contacting anthing under there and stops it will shut down the compressor and wont work

Is the fan on the bottom on? Do you hear the compressor kick off and on within a minute? No/ Is the evaporator fan running? Do you have frost on the evaporator? Frost is a sign that the defrost isnt working. If evap fan doesnt run it wont cool the refrigerator. If everything is running and no frost buildup in freezer then you have a sealed system problem and need of a tech.

Sounds like your unit may be a bit short of refrigerant and the compressor is therefore cutting out on low pressure.