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DJT
21-12-2007, 11:05 AM
Can anyone give me an idea of what pressure to expect on a domestic fridge freezer system when the compressor isn't running? When the compressor cuts in is this likely to change and if so what would a typical value be? Is it possible to tell if a compressor is working OK if the coolant has been lost and the system needs re-gassing or does it need re-gassing first and then readings taken?

Many thanks in advance.

Toosh
21-12-2007, 01:31 PM
Can anyone give me an idea of what pressure to expect on a domestic fridge freezer system when the compressor isn't running? When the compressor cuts in is this likely to change and if so what would a typical value be? Is it possible to tell if a compressor is working OK if the coolant has been lost and the system needs re-gassing or does it need re-gassing first and then readings taken?

Many thanks in advance.

Hi I am confused by your question are you a refrigeration tech.when a compressor is idle the pressure temp should show ambient temp, when the compressor runs this all changes and if you know what you are doing it will all pan out.

TRASH101
21-12-2007, 01:47 PM
The static/ standing pressure of the system has a direct corellation with the average temp of all the system components and the pressure/ temp relationship of the refrigerant used. Be careful now because working on pressurised systems can cause serious injury and/ or prosecution for venting enviromentally unfriendly gas.

pendlesteve
21-12-2007, 03:20 PM
If people are asking questions like this they should not be in the trade.

DJT
21-12-2007, 03:23 PM
No I am not refrigerant tech at all, far from it. I'm a maintenance electrician by trade but my freezer has just packed in. I posted a previous request for help but I was dragging it down into a "get ammunition because I'm being ripped off" debate (for which I apologise) The engineer took readings 2 days ago when he told me the compressor was working. Without retesting it he then told me yesterday it had failed. I have access to pressure gauges at work and just wanted to know/compare these readings to try and establish if the compressor was actually working or if there was a blockage etc. but I guess it's not that simple. (There was a reading of about 3PSI after re-gassing, when he started the compressor up it never altered and the temperature never changed.) I was told this was normal and the pressure would have actually gone up to 15-20PSI had the compressor been faulty.

I do understand that the pressure and temperature will vary throughout the system but as to what sort of readings to expect I have no idea. I would have expected a change in system pressure if the compressor was working, not if it wasn't, but as I said earlier I'm not a fridge engineer at all.

Anyway this is all irrelevant now as he has refunded most of the money for re-gassing as it wasn't that, and both of us are happy with the outcome. The freezer is being scrapped and we already have a new fridge and I've scrounged my Dad's old freezer as he doesn't use it now he's on his own.

Can I thank all of you who responded for my requests for help. I do appreciate the time you took in reading this and in posting replies.

taz24
21-12-2007, 07:29 PM
Can I thank all of you who responded for my requests for help. I do appreciate the time you took in reading this and in posting replies.


Hi DJT.

I understand your need to find a solution to your fridge freezer problem but I would not advise you of attempting to fit the gauges yourself.
You are not alowed to work with refrigerants unless you hold a safe gas handling qualification.

Most people on this forum I hope would not encourage you to do it and therfore I doubt anyone would give you the advice you need..

You are between a rock and a hard place but by asking us to help you, you are putting us in a position where we should not be.
I feel for your plight but you realy should let somone who knows what they are doing test the fridge.

To help you out I would look at it for you just to put your mind at ease and let you know what the problem is. Where are you?

taz

DJT
21-12-2007, 11:59 PM
As I said earlier I'm not in the trade, and the engineer has now refunded the majority of the money. I was attempting to check if what he had told me was correct. I also wanted to see if the pressure had changed from when he said the compressor was working, to when he said it had failed, but this isn't an issue any more.

For the record, although I have never worked on a refrigeration system I do work on high pressure hydraulics up to 6,000PSI, pneumatic systems of 90PSI and vacuum lifting equipment. I also work on HV equipment up to 11KV, right down to changing lamps and everything in between, including gas furnaces and burner systems. I was trained on these by Stordy but I'm not korgi registered either.

I do understand that you have to be careful telling people how to test systems in case something goes wrong though, especially where people now look for the slightest excuse to sue someone; and if people are asking basic questions should they really be messing in the first place.

Well it's all sorted out now anyway - the freezer is scrap and I won't be taking anything apart. I just want to thank you to all of those who helped me with this and my previous post, especially Taz for his offer to have a look at it.

Thread closed.