iceman007
04-07-2004, 05:48 PM
Hello,
I need to visit a bar in the morning (not quite yet alcoholic) to have a look at a searle cellar cooler. Another refrigeration company have been out and have been unable to remedy the fault. This is what I have been told.
Twin fan searle evaporator in the cellar, on the nameplate stating a medium of R12, R22,R502. Upstairs a Unite Hermetique condenser/compressor. Plate on the compressor shows it runs on R404A. First thing that worries me is even though I have been told the cap tube will run on 404A, the oil is not compatible-mineral for the older gases and POE for 404A.
The standing pressure is around 100psi-ambient temp was about 16-18 degrees C. Over the last few days the evaporator had been icing up, so they were switching it all off and then restarting it when the ice had melted. Since I think the end of last week, they are switching on the control box and the compressor and condenser fans momentarily start and stop straight away. On the control box there are two contactors- I am assuming one for the compressor and the other for the electric defrost, and a main RCD with a bank of breakers inside the box. The contactors try to pull in, but trip straight out again along with the main RCD.
I spoke with the customer and he says that the other firm had told him the start capacitor was to blame, which I believe isn't likely. The interesting thing is that the incoming power to the control box from the mains is 240V, but he says that at the condenser the voltage as it goes into the isolator is only about 180V. Apparently the compressor isn't grounded and is OK. When the lives are taken out of the electric box for the compressor, the breakers don't trip, but obviously the contactors don't pull in either as the whole condenser was isolated.
For starters I don't think it possible to run the system with incompatible refrigerant ratings, but can't understand where the voltage drop comes from, so I am assuming the low voltage is causing the compressor to draw too many amps and trip the breaker. I am leaning towards a control problem, but have no clear explantion for the sudden ice. Apparently the condensing set was installed about two years ago-pipework is original.I would have gone over the weekend except for recovering from flu.
I could really use some ideas on this if you have any !!
Best Wishes
James
I need to visit a bar in the morning (not quite yet alcoholic) to have a look at a searle cellar cooler. Another refrigeration company have been out and have been unable to remedy the fault. This is what I have been told.
Twin fan searle evaporator in the cellar, on the nameplate stating a medium of R12, R22,R502. Upstairs a Unite Hermetique condenser/compressor. Plate on the compressor shows it runs on R404A. First thing that worries me is even though I have been told the cap tube will run on 404A, the oil is not compatible-mineral for the older gases and POE for 404A.
The standing pressure is around 100psi-ambient temp was about 16-18 degrees C. Over the last few days the evaporator had been icing up, so they were switching it all off and then restarting it when the ice had melted. Since I think the end of last week, they are switching on the control box and the compressor and condenser fans momentarily start and stop straight away. On the control box there are two contactors- I am assuming one for the compressor and the other for the electric defrost, and a main RCD with a bank of breakers inside the box. The contactors try to pull in, but trip straight out again along with the main RCD.
I spoke with the customer and he says that the other firm had told him the start capacitor was to blame, which I believe isn't likely. The interesting thing is that the incoming power to the control box from the mains is 240V, but he says that at the condenser the voltage as it goes into the isolator is only about 180V. Apparently the compressor isn't grounded and is OK. When the lives are taken out of the electric box for the compressor, the breakers don't trip, but obviously the contactors don't pull in either as the whole condenser was isolated.
For starters I don't think it possible to run the system with incompatible refrigerant ratings, but can't understand where the voltage drop comes from, so I am assuming the low voltage is causing the compressor to draw too many amps and trip the breaker. I am leaning towards a control problem, but have no clear explantion for the sudden ice. Apparently the condensing set was installed about two years ago-pipework is original.I would have gone over the weekend except for recovering from flu.
I could really use some ideas on this if you have any !!
Best Wishes
James