Pressure variation

[properdouble]

Hi I have been working on the walk in fridge on Tuesday and after checking pressure on shrader valve gauge started to rising from 1.5 to 3 bars then stayed there for a minute just to drop to 1 bar and rised again up yo 2 bars then up to 3 basically the pressure gauge was playing around and didn't sabilize at all.what can be wrong in situation like this???
P;ease help Iam new to this job.

[sedgy]

Hi propper ,
are you saying whilst you had your vac pump on the psi raised?

[nike123]

Is this one compressor and one evaporator system or you have multiple evaporators on one compressor?

[properdouble]

Hi there was one evaporator and one compresor wich was outside basically it was annual service so i just connected gauge blue to check pressure and then this start happening after words.I started job this week person Iam learning off isn't much expirience too so we just connect gauge to shreder valve and that what start happening there was no vac as far as iam concerned at all.Iam confused cause I have no one who could explain anything to me realy .How do you check presssure on service properly. Plus fridge was not going down at all stayed about 5 6 degrees while set to 2 altough kitchen stuff all the time kept opening doors and also evaporator was a bit iced up so we deiced it with powertorch .Please help.

[Grizzly]

It sounds as if you are short cycling on LP.
You need to establish your operating pressures and temperatures.
Basically a blocked evaporator will drop the system LP like a stone.
Also the excessive ice build up on the evap will compound the situation.
Deice the evap,set the system to work and monitor your operating pressures and temps.
Your kitchen staff movements may well be an issue?
As each time they enter they will be adding moisture.
Are there curtain strips across the threshold?
Let us know how you get on.
Grizzly

[sedgy]

properdouble, all you are telling us is that you are not safe to work on your own , you connected the blue gauge that's the suction side, but where did you connect it too?
you say it was 56 degrees?
the unit has to run with your gauges on , in the right shrader points, blue to the suction red to the discharge and with all the valves closed on your gauges then with your compariter, with experiance you will be able to see what the fridge is doing

[Gary]

Pressure doesn't tell us anything if we don't know what refrigerant is in the system.

[Scramjetman]

There's some good reading around this forum - particularly in the Fundementals section which I think will be of benefit. You probably need to be doing a lot of reading and understanding or you may end up turning your plant (or someone else's) into a boat anchor. It's easy to do if you don't have enough knowledge.

[properdouble]

I meant 5 maybe 6 degrees not 56 .I have connected gauge blue to the law pressure shrader valve near compressor on the condensing unit.Fridge was working apart from iced up evaporator and pressure variation during the test.I just wanted ask what could be wrong what sort of remedial put in this case after service should it be :full leak check,faulty defrost probe as far as i remember there was no curtains.