View Full Version : freezer low suction pressure
eyresy
29-04-2014, 07:01 PM
Hi I have a copeland scroll condensing unit running a freezer coldroom, the unit gets down to -21c in no time and sight glass full with the occasional bubble . The only worry I have is the suction pressure is about 4-6psi which to me is too low. Liquid pressure is 200psi it has a new drier exp valve and orifice. So no blockages. Any info would be great
Alex
frank
29-04-2014, 07:07 PM
Without knowing the refrigerant and suction pipe temperature we won't be able to comment
eyresy
29-04-2014, 07:42 PM
Sorry frank its on 404a I haven't taken a suction pipe temp
frank
29-04-2014, 08:12 PM
I've been working on a CO2 tank cooler today on 404a with a suction pressure of 5psig and a discharge pressure of 200 psig when I got there
Got the discharge pressure down to 105psig by deep cleaning the condenser then found that it was quite short of gas as the pipe temp was +7C.....didn't help that there was hardly any lagging on the pipe :p...oh ...and discovered that it had an R22 TEV :rolleyes:
Can you post a full set of system readings?
NewmanRef
29-04-2014, 08:24 PM
I've been working on a CO2 tank cooler today on 404a with a suction pressure of 5psig and a discharge pressure of 200 psig when I got there
Got the discharge pressure down to 105psig by deep cleaning the condenser then found that it was quite short of gas as the pipe temp was +7C.....didn't help that there was hardly any lagging on the pipe :p...oh ...and discovered that it had an R22 TEV :rolleyes:
Can you post a full set of system readings?
You weren't at a nationwide bank in reading were you?
eyresy
29-04-2014, 09:16 PM
Condensing unit about6 month old was on r22
cadwaladr
29-04-2014, 10:32 PM
Check the txv,put a 404a valve on if it has not got one already and check bulb contact on outlet.
frank
30-04-2014, 07:42 AM
You weren't at a nationwide bank in reading were you?
Do they have a 12tonne CO2 tank as well?
eyresy
30-04-2014, 03:53 PM
The valve is 404a and I checked the bulb which was sat on top of tue pipe so I moved it to the side which helped a little. Im gonna change the valve tomorrow and see if that helps. Cheers frank
monkey spanners
30-04-2014, 06:26 PM
Has it got the correct orifice in it? It would needed a bigger one than it had on R22.
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