Printable View
hi all...my first delve into this site.....
i dont normally deal with celler cooling but its a favour.. The beermaster r134a unit is only blowing ambient air. the condensor unit is not kicking in. i have tried to do a shutdown reset but nothing. power ok to condensor unit and compressor starts ok when the contactor is depressed with a screwdriver.
new contactor, capacitor, liquid line sensor ???? and ideas or am i missing a trick with the evap unit ??
Is the cooling light on, on the evap control panel? Is solenoid valve inside evap energised? If yes and yes, has it got any gas in it?
Andy
Is the compressor pumping? Do you have a difference of pressures either side of it when it is running?Quote:
Originally Posted by garytreez
Have yo checked the contactor coil. It may be burned out. Good Luck
First thing to check with a 'unit not running' call is, is the thermostat asking for cooling? Should the unit actually be running? If it should and the unit still don't work then follow you way through the control circuit till you find what is stopping it running, be it a tripped hp switch or blown coil on the contactor etc.
Jon
thanks for all the advice and i think that it points to the contactor. the gas is good, chill light is on at the evap. The compresor is good when the contactor is pushed in manually.
when looking at any refrigeration system on a call out like this as previously mentioned you have to start from scratch.
check the obvious there is power then go through the control circuit from indoor to outdoor and go through the elimination process.
if you stick to this basic method you will always find the fault.
some times it is just somthing simple like a burnt out contactor coil but you look that hard you miss these simple faults then start panicing and flapping because you think its something serious but are unable to find the problem.
i have not posted this to offend anyone it is more a little advice for new comers to the industry.
all refrigeration systems are the same as of remote systems some have more saftey devices etc than others and some are larger than others but the method of elimination is the same.
The obvious way to check if the condensing unit / compressor is getting a run signal.
Would be to meter the A1 or A2
( live supply can be to either dependant upon how the unit is wired) terminal's on the contactor to check that it is being asked to run?
Basically what MS is suggesting.
Grizzly
Hi guys I am in a similar problem I've just changed a contactor because the unit was cutting in running for 5 min and cutting out iv adjusted the hp and lp switch and cleaned the condensor coil checked that it wasn't cutting out on hp there is the correct amount of refrigerant in system I thought it was the contactor however the unit is still cutting out and the coldroom is not as cool as it should be any ideas have I given enough info sorry it's my first time replying on here ????
hi garytreez,
replying to the original thread, the beermaster , I think is controled from the stat on the evap to the solinoid valve< inside the evap< so you would hear the valve opening when you turn the stat down . all the best.
You need to find what is turning the unit on and off every five minutes, then once you have found it you can decide if it should be turning the unit on and off, or if it has gone faulty.Quote:
Originally Posted by bushell01
When the unit is running, the system will have a live feed from where the control circuit starts (maybe a fuse in a panel, or some other live) then through all the various controls and safety devices and ends at the contactor coil. Once you have familiarised yourself with the way the system is wired, you can run it and once the unit stops, check along the circuit to see what if turning it off.
Some controllers are set to run the compressor on for so many minutes and then off, etc, when the probe fails, but you would have a fault code i expect with this.
What make of unit is it? age? refrigerant? 3ph or 1ph? size of room? (the bigger the system the more controls it is likely to have)
You will likely get a better response in future by starting a new thread thats just about the problem you are working on.
Jon :)