Refrigeration not handling both boxes

[W.T.Gross]

For refrigeration we have a Grunert AC450 supplying both the fridge and freezer. Dual thermostats, dual solenoids. When just one side is calling for freon, it works very well. But if both sides call, neither side will cool, and sometimes continue with temp rise. There is a 1/4 inch pressure line connected to a tee that connects to two 1/4 inch lines going to the solenoids. Both solenoids and coils have been replaced along with both expansion valves in the boxes. Refrigerant is full. Has anyone had a similar problem, and if so how did you resolve??

[paulajayne]

Rewire so that when one is calling the other cannot. Should not cause a problem with temps once both are down to working levels.

[W.T.Gross]

Originally Posted by paulajayne

Rewire so that when one is calling the other cannot. Should not cause a problem with temps once both are down to working levels.

Thank you for the comment. I was thinking the same thing, but have no idea of what device I may need or the knowledge of how to wire.

[Richard Kollmann]

Originally Posted by W.T.Gross

For refrigeration we have a Grunert AC450 supplying both the fridge and freezer. Dual thermostats, dual solenoids. When just one side is calling for freon, it works very well. But if both sides call, neither side will cool, and sometimes continue with temp rise. There is a 1/4 inch pressure line connected to a tee that connects to two 1/4 inch lines going to the solenoids. Both solenoids and coils have been replaced along with both expansion valves in the boxes. Refrigerant is full. Has anyone had a similar problem, and if so how did you resolve??

How are you judging that refrigerant quantity is correct? With its large refrigerant receiver tank it needs more refrigerant because of the dual boxes. Is sight glass full with both solenoids energized? If refrigerant volume is two pounds or more and both boxes are not cooling I would first check to see if king valve on receiver is in the full open position. There must be a restriction in liquid high pressure line between receiver and the separating tee to each solenoid. Problem is not in the size of 1/4 inch tubing on that small compressor system if high pressure at king valve is over 115 psi.

[W.T.Gross]

Originally Posted by Richard Kollmann

How are you judging that refrigerant quantity is correct? With its large refrigerant receiver tank it needs more refrigerant because of the dual boxes. Is sight glass full with both solenoids energized? If refrigerant volume is two pounds or more and both boxes are not cooling I would first check to see if king valve on receiver is in the full open position. There must be a restriction in liquid high pressure line between receiver and the separating tee to each solenoid. Problem is not in the size of 1/4 inch tubing on that small compressor system if high pressure at king valve is over 115 psi.

I am judging my refrigerant level from my refrigeration tech who just installed the components listed above. He's been a refrigeration guy for 30 years.
His solution is to run new 3/8 copper to the boxes and move the solenoids from the cabinet to the boxes. I was hoping for a less expensive solution.

[Richard Kollmann]

Originally Posted by W.T.Gross

I am judging my refrigerant level from my refrigeration tech who just installed the components listed above. He's been a refrigeration guy for 30 years.
His solution is to run new 3/8 copper to the boxes and move the solenoids from the cabinet to the boxes. I was hoping for a less expensive solution.

Assuming the system is serviced correctly and pressure at king valve is adequate more than 115 psi. Ask your Tech if the combined orifices size, he chose, in expansion valves are designed to support 3400 Btu when combined.

[W.T.Gross]

Originally Posted by Richard Kollmann

Assuming the system is serviced correctly and pressure at king valve is adequate more than 115 psi. Ask your Tech if the combined orifices size, he chose, in expansion valves are designed to support 3400 Btu when combined.

I will do that!! Thank you for the advice!!