I recently came across a system that was out on oil pressure i reset the system and observed my oil pressure. I was running 50 psi of oil pressure. I went ahead and replaced the compressor contactor due to it looking pretty burnt. I put the system into defrost to check pump-down. This has a Sorit 20-0/100. When the system pumps down. the high pressure line bleeds through the bottom pilot line causing compressor short cycling. I re-built the EPR valve and same thing. (The high pressure line comes off the discharge line about 2 ft. from the compressor service valve.)
I've done a little research and am thinking the high pressure line needs a solenoid to shut it off during pump down and the liquid line solenoid that is in manual lift needs replaced to completley pump the system down.
I think you need to look sideways.
I wonder if you aren't building pressure from another source.
Yes, the high pressure does bleed through, but down it bleed enough to cause the compressor to short cycle is the question.
I honestly do not know the answer, but I would put some work into eliminating other causes before installing a solenoid.
I verified it was the EPR building pressure by pinching off the bottom pilot line. If I'm thinking right. If the high pressure line shuts off with the solenoid on the EPR won't the valve go wide open due to the high pressure line being the closing force on the valve. Which makes me think the solenoid is worthless in this scenerio and it should have an orit instead and a simple pump down
Go to Sporlan.com and look for Bulletin 90-20 which will show how the valve works. However, Sporlan made 3 generations of this valve that had the solenoid in different positions and they acted differently. You may have to identify the age and version of the valve and look for some older literature.
Normally the (S)ORIT will only bleed high to low during modulation and not during pumpdown.
That is what I thought, also.
Originally Posted by BDOLIN
When you said you 'rebuilt' the valve, what did you do, exactly?
I installed new internal parts and replaced the pilot assembly
I appreciate the info guys. Still pretty new. Especially to the supermarket world. Any info is greatly appreciated:cheers: