My beer's too warm!!!

[bob007]

my local has an issue with his cellar cooling that i had a look at today it has 2 evap running off a prestcold comp (semi hermetic), the cellar temp has been going up and is now at 21c, he used to have a local engineer look after his coolers ect.. but he has not been able to contact him for about a year( by the looks of some of the work he has done on his walk in freezer i think he has done a runner) so no one has worked on it for years , it had a leak on the l/p switch which has been repaired the pressures where- h/p =5.2 and the l/p =2.8 bar there was very little in the sight glass and the compressor was red hot it seemed the temp difference between the suction inlet and the discharge outlet was about 45c. After checking for more leaks i added some R134a till sight glass was full and cleaned a dirty condenser and fan after this compressor settled down in temp but still had a lack of cooling.
NOTE one evap tev is marked R12 the other R134a p/t chart indicated r134a this is why i added it.
here are some readings 1 hour after above work was done.

h/p-9.5 bar
condenser outlet temp-34
is this 3c sub cooling

l/p-4.1bar

now this is the interesting bit im getting two different readings of temp from both evaps suction 1-22c 2-25c the have equalizer lines on both. the tev's are just cool to touch no frosting ect as it was on first view.


is it overcharged?
is the suction valve faulty on comp?
is it a tev vault or both?

any ideas.

[paul thompson]

is compressor pumping

[bob007]

yes mate im going back tomoz will do a pump down on it., my concern is that it got so hot , maybe a valve is on the way out. i wanted to make sure i wasnt missing something. What did you think of them pressures.

[bob007]

While i thing about it on my gauges the needle on the LP was oscolating? could this indicate a comp fault? or faulty manifold.

[richelli]

Am I right in saying you have charged 134a because a pressure temp chart, came up with pressure which lead you to believe it has 134a in it. I would say you could have the wrong gas in. The guy before may have only had a 134a valve and used that as a get by.

Your head pressure also seems way to low. I would say the system was probably on r12, so you would need a drop in for r12 for instance R413a. Does it not say on the condensing unit anywhere what refrigerant is in there?

(This is all asuming as said above the comp isnt knackered)

[bob007]

Am I right in saying you have charged 134a because a pressure temp chart, came up with pressure which lead you to believe it has 134a in it. I would say you could have the wrong gas in. The guy before may have only had a 134a valve and used that as a get by.

Your head pressure also seems way to low. I would say the system was probably on r12, so you would need a drop in for r12 for instance R413a. Does it not say on the condensing unit anywhere what refrigerant is in there?

(This is all asuming as said above the comp isnt knackered)

their was not much gas to start with but the chart did lead me to 134 and the tev confirmed this to me(rightly or wrongly) either way their would be some sort of coolling wouldnt there?
their is no mention on the condenser of the type of refigerant.

[monkey spanners]

What oil is it running, mineral or poe?

What model is the compressor, a clue to its designed refrigerant usage would be in the model number.

How does the sight glass look now? Milky?

If there wasn't much refrigerant in there, why put it back in after you had recovered, fixed leak, leak tested the system with ofn and re charged?
You could have gone with a fresh charge and removed any possibility of previous bodging/hacking contaminating the new refrigerant.

[bob007]

What oil is it running, mineral or poe?

What model is the compressor, a clue to its designed refrigerant usage would be in the model number.

How does the sight glass look now? Milky?

If there wasn't much refrigerant in there, why put it back in after you had recovered, fixed leak, leak tested the system with ofn and re charged?
You could have gone with a fresh charge and removed any possibility of previous bodging/hacking contaminating the new refrigerant.

I have assumed its poe as its on 134, i havnt got the mod number with me will get it tomorrow. i should have started from scratch with the charge it might come back and bit me.
the sight glass is clear.


have you had needle on gauges oscilate before? by about 0.1-0.2bar eack way as the system is running.

[monkey spanners]

have you had needle on gauges oscilate before? by about 0.1-0.2bar eack way as the system is running.

I've got those oil filled gauges so the needles don't flutter, so i couldn't say what is normal. I'd try and see how good a vacuum it can pull (shut suction valve) and then turn it off and see if it hold, would expect at least 15"hg or -.5bar and to not rise up for a few minutes it the valves in the comp are good. Don't run the comp for too long in a vacuum.

An R134a txv will work ok with R12 or a drop in. They both run similar pressures. So you can't always tell just by looking at the txv.

Jon

[bob007]

if the comp is fine what else will cause them pressures and no cooling, wouldnt it take a large amount of contaminates to stop it cooling?

[bob007]

UPDATE- Have been to the account this morning and completed a compression test, took about 2 mins to get to atmos then pressure equilized with h/p at 5.5bar.
ITS KNACKERED!!!

The unit is a prestcold pk10x/0017 p-07 its dated 1997.
Ive had a look in the climate catalogand its on ester oil which indicates that it is r134a as R12 would be on mineral?
The account has asked me to give him a price for repair/replace.
would it be cheaper to replace the whole condenser unit?
I cant seem to see spares for this model but have seen a replacement for 1100 quid wow!!!

any advise??

[mad fridgie]

UPDATE- Have been to the account this morning and completed a compression test, took about 2 mins to get to atmos then pressure equilized with h/p at 5.5bar.
ITS KNACKERED!!!

The unit is a prestcold pk10x/0017 p-07 its dated 1997.
Ive had a look in the climate catalogand its on ester oil which indicates that it is r134a as R12 would be on mineral?
The account has asked me to give him a price for repair/replace.
would it be cheaper to replace the whole condenser unit?
I cant seem to see spares for this model but have seen a replacement for 1100 quid wow!!!

any advise??

13 years life, 1100 quid, less than 100 quid a year, less than 30pence aday, how much is a pint of beer? ask him what is profit margin is, a bet one pint aday would cover this!!!! what a bargin !!!!!, Bet you could not change a car engine for this,

[bob007]

13 years life, 1100 quid, less than 100 quid a year, less than 30pence aday, how much is a pint of beer? ask him what is profit margin is, a bet one pint aday would cover this!!!! what a bargin !!!!!, Bet you could not change a car engine for this,

Im sold haha, but would it be cheaper for a runof the mill condesing unit?

[mad fridgie]

Im sold haha, but would it be cheaper for a runof the mill condesing unit?

Sorry can not help on that one, we use dollars not quids.

[Gingerair]

Think the x in Prestcold model numbers signifies POE.
This however isn't an indication whether the units on a HFC or HCFC.
POE was used with their units for R22....but to be honest, am not sure about R134a, presume it would be the same though.
.....although i could be wrong...

Have you checked the unit for acidity ?
It may require a clean up whatever you decide to do..

[raz5]

Have a look at the beermaster range from climate, installed a few now and they do the job and give climate all the details of the cellar and they will source the size etc

[bob007]

Have a look at the beermaster range from climate, installed a few now and they do the job and give climate all the details of the cellar and they will source the size etc

Ive installed a few of these myself but was hoping to use the 2x searle evaps that are in the cellar.
maybe just use a compatible condensing unit running on 134a as account wants a low cost option!

[monkey spanners]

Cheapest thing would be a rebuilt compressor from some one like Aces or Preston or such, would be about half the price of new, or you can buy through climate centre.

Depends on the state of the condenser whether it is worth putting a new comp on, as an example of how long these things can run for if looked after the one on the farm i was at today was new in 1966 and still running.

[bob007]

Cheapest thing would be a rebuilt compressor from some one like Aces or Preston or such, would be about half the price of new, or you can buy through climate centre.

Depends on the state of the condenser whether it is worth putting a new comp on, as an example of how long these things can run for if looked after the one on the farm i was at today was new in 1966 and still running.

The one that is in is dated 1997 but by the looks of it has not been looked after, condenser looks ok after a clean up but if i fit a new comp it might put pressure on the older parts of the system( some corrosion an evap sides) and i know its near on impossible to repair leaks on them,have tried in the past.
Im concerned about fitting new comp and then having to go back all the time for other repairs, i might give him a quote for a new system and let him shop around.

[monkey spanners]

The one that is in is dated 1997 but by the looks of it has not been looked after, condenser looks ok after a clean up but if i fit a new comp it might put pressure on the older parts of the system( some corrosion an evap sides) and i know its near on impossible to repair leaks on them,have tried in the past.
Im concerned about fitting new comp and then having to go back all the time for other repairs, i might give him a quote for a new system and let him shop around.

Why not just give the customer a price for a replacement comp and for a replacement system. Then its their decision. That way if the evap goes pop in the future and they moan you can point out they were given the option of a new system and chose the cheaper option.

[bob007]

Why not just give the customer a price for a replacement comp and for a replacement system. Then its their decision. That way if the evap goes pop in the future and they moan you can point out they were given the option of a new system and chose the cheaper option.

Im going to ring round on monday to climate and es refrig see if i can get some prices for the comp.
Do you know of any more company that do refurb semi hermetic, prestcold ect...?

[monkey spanners]

Depends where you are in the uk but i expect they would get it delivered to you anyway.

http://www.acescomp.co.uk/

http://www.prestoncompressors.com/profile.htm

http://www.dowdingandmills.com/trade_news_05_nov_02.htm

I have used all os these and been happy with the compressors.
If you have a copy of the RAC year book there will be a list of rebuilders in there or look for ads in the free service engineer book that you can sometimes get at the wholesalers.

Jon

[bob007]

Depends where you are in the uk but i expect they would get it delivered to you anyway.

http://www.acescomp.co.uk/

http://www.prestoncompressors.com/profile.htm

http://www.dowdingandmills.com/trade_news_05_nov_02.htm

I have used all os these and been happy with the compressors.
If you have a copy of the RAC year book there will be a list of rebuilders in there or look for ads in the free service engineer book that you can sometimes get at the wholesalers.

Jon

Thanks for your help mate.
i will gve them a call.

[Reeferman27]

The one that is in is dated 1997 but by the looks of it has not been looked after, condenser looks ok after a clean up but if i fit a new comp it might put pressure on the older parts of the system( some corrosion an evap sides) and i know its near on impossible to repair leaks on them,have tried in the past.
Im concerned about fitting new comp and then having to go back all the time for other repairs, i might give him a quote for a new system and let him shop around.

How about doing a system strength test with OFN, 1.1 X HP setting or standing pressure of refrigerant @55C.

[WCC73]

Cheapest option would be to install a l'unite cond unit. I would prob think a 1 1/ horse. I think that's a Caj 4425yhr( off the top of me head, best check first)

[Electrocoolman]

With regards to your previous post on the same system.....I see you managed to buy some refrigerant...e bay?

[bob007]

With regards to your previous post on the same system.....I see you managed to buy some refrigerant...e bay?

Wasnt planning on going down that route, found myself a good supplier locally.