[shawnml9]

Had a R-22 walk in go down last night ..Pressures on arrival were 440/70 off on high pressure..compressor pumps down fine..I am leaning toward head pressure control being the problem but I would think my Suction would be down..any ideas

 

[engineerdave]

No airflow across your Condenser Coils.

 

[shawnml9]

unit has 2 other compressors using same condenser they are running fine...also it was about 20 degrees and windy as hell

 

[Special-K]

Had a R-22 walk in go down last night ..Pressures on arrival were 440/70 off on high pressure..compressor pumps down fine..I am leaning toward head pressure control being the problem but I would think my Suction would be down..any ideas

Head pressure control as in fan cycle or Headmaster?

You can check a Headmaster in that situation by comparing the temps of the line exiting the condenser and the liquid line leaving the Headmaster. If the line leaving teh Headmaster is way hotter than the line leaving the condenser then the valve is bypassing. If it's bypassing when the head pressure is significantly higher than the set point then it's bad.

If you have a bad fan cycle control....the fans won't be running.

 

[shawnml9]

Its a head master...now if it is bad should'nt suction be down

 

[engineerdave]

Non-condensables?

 

[engineerdave]

Two other compressors on the same walk-in? Okay, then you have something specific to that pump...

 

[shawnml9]

the other compressors share same condenser along with Ice Machine..trying to remember who makes this unit..Baja Fresh has them built for them

 

[engineerdave]

So it's a seperate circuit within the Condenser Bundle. Check Kfridge's Headmaster. Make sure that portion of your condenser is not packed with bird droppings or other garbage. Any other recent work on this unit?

 

[shawnml9]

according to cust. no other work has been done....I am wondering with the snow/ice storm we had if a portion of condenser is frozen..

 

[Special-K]

according to cust. no other work has been done....I am wondering with the snow/ice storm we had if a portion of condenser is frozen..

The heat from the condenser should melt it.

Is it a Heatcraft unit? It sounds like a knockoff of the unit they make for McDonalds. One box, a multi circuit condenser, common fans, 2-3 compressors and up to two aux circuits for ice machines of beverage refrigeration.

It could be overcharged, but it wouldn't just start giving trouble out of the blue. I think you have a headmaster stuck in bypass.

 

[shawnml9]

Yea it's basically same setup as McD's and I think you are right about press.control...supposed to be 50 tomorrow be able to get a better handle on it

 

[itsiceman]

Sounds like Omni-temp and a bad headmaster. There is one for each compressor.