404a walk in freezer need info

[texinport]

i have a walk in freezer i built 5 years ago it has worked fine all this time up tell 2 weeks ago it lost power on one side of the breaker. replaced the breaker and it worked fine for 2 weeks.
now it is still cooling and running for the most part the compressor starts up and a couple seconds later it shuts off the compressor. i got it to run fine by dropping the box temp at the thermostat to -20 to -10 it is keeping the box between -5 to 7 it ran like that working fine for 2 days now the compressor is turning on and right back off it runs for 30 sec to 3 min. it dos have a little ice buildup on the suc line for about 2 inches past the isolation at the compressor.
any info will help suc pre is 20psi liq line is 120psi ish going to recheck them today

[frostline]

Hi, what temp is the room at for your suction pressure? 137kpa pt's to about -27 sst..... thats quite low for temps of -5 to +7 on 404. Your head pressure is also very low.... you need to find out what is causing the comp to drop out. There are a number of things that can cause these issues and pressures so first find out what is cutting the comp out and you'll find the cause. Check the pressure switches, in particular the low pressure switch. Also check the compressor overload and the contactor thermal overload. Always look at the basics first! Safety protection systems, power supply and refrigerant volume. Does the comp check out electrically? How many amps is it drawing compared to its spec? I could go on all day but basically just find out WHAT is stopping the comp.

[texinport]

thanks for the info im thinking it had an ice plug and a little low on refer and was triping out the comp all the power is good that was my firs thought. i think its running ok now i run a 1 hour defrost timer last night and from what i see today is it is running ok now added some refer to it and reset the defrost timer too 5 hours at 30 min each they wear set at 15 min. today outside air was 56.3 suc at the comp 12psi liq line 190psi air in evap 15 and out 12 suc temp at comp 12 and liq temp 65. im going back today around 1pm to re check every thing any more input would help thanks

i have been out of the loop on hvac for 5 years this walkin was the last one i built