Drew
23-04-2009, 10:51 AM
I recentley changed an old underbar fridge from being controlled by an LP switch to a digital carel control. The fridge is a 3 glass door underbar with a large static coil (no fan) mounted on the ceiling. The system cycles directley off the stat with no pump down soleniod valve. The coil has a drip tray underneath it .
Normally I would set the set point at 2 degrees C with a 3 degree differential.
This i did and found that the compressor turned off at 2, but still the cabinet came further down to -1 degree C . I have seen cabinets over shoot the mark by maybe a degree, but this is 3 degrees and would freeze product? Could it be overcharged and all the refrigerant in the overfull reciever is still flowing excesivelly through? Or is due to the static coil holding more refigerant that still is evaporating ( more so than a fan assited coil)??
I have had to set the set point at 5 degrees (with a 1/2 degree diff) to stop the product freezing. Now the cabinet compressor turns off at 5 degees , but the temp still drops to 1 degree and turns back on at 5 1/2 degree. Is this common on a static coil?
Normally I would set the set point at 2 degrees C with a 3 degree differential.
This i did and found that the compressor turned off at 2, but still the cabinet came further down to -1 degree C . I have seen cabinets over shoot the mark by maybe a degree, but this is 3 degrees and would freeze product? Could it be overcharged and all the refrigerant in the overfull reciever is still flowing excesivelly through? Or is due to the static coil holding more refigerant that still is evaporating ( more so than a fan assited coil)??
I have had to set the set point at 5 degrees (with a 1/2 degree diff) to stop the product freezing. Now the cabinet compressor turns off at 5 degees , but the temp still drops to 1 degree and turns back on at 5 1/2 degree. Is this common on a static coil?