Reach in cooler issues

[nicksab]

hey everyone,

I am having issues with my display cooler

Symptoms: cooler not going any lower than 62F and txv valves /distributor icying upon both evaporators.

Measurements:

Refrigerant: R401A

suction line: 6 PSI @ 58F
liquid line : 90 PSI @ 80 F

according to R401A P/T chart,

superheat= 57F
subcooling= 5F

What s the cause of the problem? how can i fix it?

Thank you for your help

[simon@parker]

air on the evap ?
air off ?
air on condenser ?
air off ?
would also check before you do any major investigation work has any new ac been fitted ?
does unit have a night blind ?
if it does pull it down see if it works then 60% of calls i used to attend were nothing to do with refrigeration probs but store conditions and air flow :)

[Tayters]

Hi Nick,

From your figures subcooling normal/too low, superheat too high. System short of refrigerant.
Requires leak repair and recharge and make sure airflow through all coils (including condenser) is good.

Cheers,
Andy.

[texas64]

I agree with Tayters. You are undercharged. Ball park pressures are around 25 psi suction, 150 psi liquid if the unit is indoors with 75 - 80 degree Fahrenheit temp. Find the leak, repair, recharge.