capsule pak question

[knthms]

I am a residential hvac installer and tech. who is crossing over to help a friend who owns a nursing home. They have a norlake capsule pack walk in freezer that they were told to replace as it couldn't be fixed. I told them I would check it out before spending the big bucks that they don't have. I arrived to find the 404a unit completly frosted up and initiated defrost. Nothing much happened except some frost melted at suction line at compressor. Compressor continued to run, evap. fans off, and frost started to form around solonoid wired into defrost timer. upon removing some ice arouns evap. I found that there were wires that appeared to go into evaporator for electric defrost. These were not getting hot. I had a doctors appt. that i was late for and am returning tomorrow. Plan to find out how defrost is terminanated and find some form of schematic. It's been fifteen years since I was in school and it is all a little fuzzy. Is this system hot gas defrost or electric or both. Why wouldn't hot gas bypass be hot enough? Owner was told compresssor was bad but it was running upon arrival! no bubbles in sight glass but with evap. iced over that doesn't tell me much!

Any help would be appreciated!!!!

[A1 Burt]

Do you have - AMP METTER - MANIFOLD GAGES -TEMP GAGE -
it sound's like you have a L-L-S-V- that is not closing allthe way ?
Is your temp controll stuck in the made possition ?
Did you front seat your suction valve to see if the compressor can pull a vacum and hold a vacum ?
Are the heater's working ? GOOD LUCK :cool:

[knthms]

was a pump down system, not hg bypass. call for defrost, llsv closes compressor not dropping out, and no electric defrost. Dual pressure not opening with low pressure; replaced!!!!!!

[jpsmith1cm]

Is LLSV leaking? See Al's comment on gauges.

Where does LPC cut out? Simply replacing a control means squat.

[A1 Burt]

KNTHMS you might need to do some testing for a few thing's to find where the system is failing need more infomation:cool: