3 Door Freezer Trouble

[waz80]

Hi Guys

Im having a bit of trouble with a 3 door freezer with 2 evaporators either side of compressor, i recently done a compressor change, replaced the liquid line drier fitted and suction burnout drier. Suction pressures is 10 - 15 psi and head pressure at 250 psi with full sight glass cabinet will only reach -13 degrees. opened tx valve to try get suction pressure up but still help, checked for pressure drop over suction drier but pressures are the same.

[Rob White]

.

You don't state what refrigerant it is running on?

If it is a common one then the suction might need to be near
5 - 8 psi rather than 10 - 15 psi. Was the compressor a
like for like exchange or did you put a different type on?

Regards

Rob

.

[install monkey]

check your txv orifice gauze isnt clogged

[FEISTY]

Is the unit designed as a " standard " or " low temp " freezer? I have this discussion with many customers who purchase a FREEZER and expect it to hold ice cream rock hard. The unit has a design temp and that's what it's made to do. Equipment suppliers rarely ask a customer how they intend on using the unit and what they will keep in it. Your temps are fine for general food items and should keep ice cream at " thick soft " consistency or scoopable. You need 15 below or better to store rock hard. Also too long or too many defrost cycles will cause the temp to recover very slowly causing a warmer than expected cabinet. Hope this helps you. Follow up with how you fix the problem. Sharing success or even mistakes just helps all of us. Have a great day.

[mikeref]

10 to 15 Psi? Take the highest figure, convert for R134a = -9 ish degrees C evap so it isn't R134a.
R404 and R507 at 15 psi is around -29 degrees C at expansion to evap, too cold and not enough refrigerant feed. Superheat will be high.
Make sure you first check the evaporator isn't iced up then (As install Guru) says, check the orifice strainer is clean. If there is any discolouration on the orifice, ( Grey to black on the outlet,) then bin it.