Meat display cases medium temp! R-22 Defrost settingS?

[isitfixedyet]

I need to know from anyone that can help? what should i set these three medium temp closed meat display cases for on time setting for defrost, its a regular paragon 8140 b type, for typical conventional defrost,,,
These cases are gravity fed, not forced air!
the other thing is, is theres a low pressure control to the compressor on the service factor tubing of a reciprocator, towards the top of the can type compressor, where the factory charges or checks the unit for pressure losses, etc; thats where some guy installed the compressor control , and i believe that its a problem to hook it up there it only short cycles the compressor during the off cycle, maybe its the valves leaking by, or its a solonid valve leaking, or finally its just not the right place to insatll a low pressure control to bring on the compressor!
am I right about this being a not a right place to install it?
this is a two question post!
I just have to get off my but after defrosting these and go and do the foot work , i guess!
I did find the defrost set at one time a day for 90 minutes! that didnt do the job!

[chillin out]

These cases are gravity fed, not forced air!

Are there heaters to defrost the coil?

Q2, you can fit a pressure switch anywhere. Try adjusting the diff.

Chillin

[Dan]

isitfixedyet, you win the prize for the most rambling question from the USA. Let's hope that you win out over the UK, once Refrigeration Idol is invented. But seriously

I need to know from anyone that can help? what should i set these three medium temp closed meat display cases for on time setting for Defrost, its a regular paragon 8140 b type, for typical conventional defrost,,,
These cases are gravity fed, not forced air!

You need 120 minutes around midnight. I think a Paragon permits this.

the other thing is, is theres a low pressure Control to the Compressor on the service factor tubing of a reciprocator, towards the top of the can type Compressor, where the factory charges or checks the unit for pressure losses,

You have stumped the judges of Refrigeration Idol with that comment! I am guessing that you mean that the low pressure control is connected to what we refer to as a "process" tube. There is nothing wrong with that.

this is a two question post!

I am smiling. You wonder about a solenoid valve not sealing. This could be your problem. Some things you didn't refer to make me wonder. Does this case have a serpentine bottom coil? These are notorious for icing up the bottom of the case.

A two hour defrost once a day should be all you need. If you have your gauges on and the suction pressure fails to rise above the Saturated suction pressure of ice melting you likely have a leaking solenoid valve. This might also explain some of your other observations.