Walk in freezer tripping on over load

[Qamar]

I am working on walk in freezer R404A Air condesing unit ,it was short cycling for 5-10 seconds. The H.p was once 300psi, L.P was 0. upon playing W/ the dual pressure switch ,system would kick in, clean cond coil H.P drop to 200 Psi. Then I close liquid line service valve to pump down system it stops but when I open L.L service system dosent kick in. it only cycles for a few seconds. I changed start and the run capicator . which shorted out the start capicitor again L.P was 115# H.P was 200#.I lowered the S.P and changed the start capicator it still does the same thing. I put TXV bulb in ice cold water as box temp was over 80*. Any advice or assistance would be appreciated. thanks

[caheiman30]

I am working on walk in freezer R404A Air condesing unit ,it was short cycling for 5-10 seconds. The H.p was once 300psi, L.P was 0. upon playing W/ the dual pressure switch ,system would kick in, clean cond coil H.P drop to 200 Psi. Then I close liquid line service valve to pump down system it stops but when I open L.L service system dosent kick in. it only cycles for a few seconds. I changed start and the run capicator . which shorted out the start capicitor again L.P was 115# H.P was 200#.I lowered the S.P and changed the start capicator it still does the same thing. I put TXV bulb in ice cold water as box temp was over 80*. Any advice or assistance would be appreciated. thanks

I had one that was doing the same thing and I found that one of the fuses was bad, but that was on a MAC unit.

[rmuntz]

Your potential relay is faulty, contacts are stuck closed.
Start capacitors are not designed to remain in the circuit for any length of time, if they do they pop.

[ar_hvac_man]

The electrical issue needs to be addressed before you start jacking with the TEV

[socotech]

Liquid line solenoid valve leaking?

[Qamar]

I changed pot. relay and s/c before i turned on i checked l.p 140# and hp 220# decreased lp to 60# ran unit it ran for45 sec and then s/c pop out. changed s/c this time it ran longer than before i checked amps on run winding was11.1 amp and start was 9.1 and common7.6 all this time start winding stays in circuit h.p was 200 and l.p 0 .ohm s-c 3 r-c 1 r-s4