At what PSIG should the thermal overload switch shut down the compressor?

Reply

  #1  
Old 01-24-18, 12:39 PM
A
Member
Thread Starter
Join Date: Jan 2018
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
At what PSIG should the thermal overload switch shut down the compressor?

Bosch/FHP model EM028 single stage 2.3 ton heat pump, vertical, top discharge. A tech was out and wrote on the invoice that the compressor does not go into overload until 600 PSIG.

As far as I know the compressor thermal overload switch is just a bi-metal immersed into compressor oil, so it operates on the temperature of that oil and not the pressure in the high pressure line. I guess there should be a corresponding value. The tech does not know it and would not call the factory even though I already paid him to come out and diagnose.

Bosch tech support is only for techs and they will not talk to the homeowner. This info is not in the installation manual. So I am stuck not knowing if that overload switch is good or not.

Thanks
 
Sponsored Links
  #2  
Old 01-24-18, 01:56 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
Sounds like the thermal overload is good to me.
 
  #3  
Old 01-24-18, 02:49 PM
A
Member
Thread Starter
Join Date: Jan 2018
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
Thanks Carlos,
Can you be more specific.
At what oil temp do you expect the compressor to overload?
At what corresponding refrigerant PSIG?
 
  #4  
Old 01-24-18, 02:56 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,426
Received 17 Votes on 14 Posts
I have never heard of a corresponding pressure.
 
  #5  
Old 01-25-18, 08:25 AM
Geochurchi's Avatar
Member
Join Date: Nov 2012
Location: USA
Posts: 4,618
Received 57 Votes on 53 Posts
What is the issue,is the compressor shutting down what are the symptoms?
Geo
 
  #6  
Old 01-25-18, 01:13 PM
A
Member
Thread Starter
Join Date: Jan 2018
Location: USA
Posts: 9
Received 0 Votes on 0 Posts
No issue. Just diagnosing if all the protection switches are in order.

When the water tower (and circulating pump) were down the high pressure limit switch did not trip. We diagnosed and found out it was a working switch but had been bypassed for apparently no reason. What puzzled me is that, even if the limit switch was bypassed, the next line of protection -- the thermal switch inside the compressor -- should have shut the compressor down but it did not. When testing at about 600 PSIG the compressor did go into overload. I cannot tell from that if the thermal switch is good or not. So I asked the pros here.
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: