walk in freezer not going into defrost

[supertek65]

JP!!!!!!

JP mod!!!!!

can we do something for breast cancer on this site????????????????????????????????????????

[royd2]

thanks guys.I was lost. we fixed it. we changed the time clock and the contactor it was pitted pretty bad and we also changed the defrost terminaion switch unit running good for now

[royd2]

idk why he wanted to change the dt switch he didnt even test it but if it were bad it would not stop from defrosting would it ? it would just stop from terminating at temo right?

[ryan1088]

defrost timer de-energizes ll solenoid valve and then compressor will run until pressure switch opens.

Hold on a second, you do refer work too??

[supertek65]

LMAO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Hold on a second, you do refer work too??

[supertek65]

LMAO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Hold on a second, you do refer work too??

[2sac]

To the OP. Slow down. Read your wiring diagrams. They tell you everything you need to know.

[VTP99]

Hold on a second, you do refer work too??

Looks like he found the right defrost timer didn't he ? So I would have to say yes to some degree.

[VTP99]

idk why he wanted to change the dt switch he didnt even test it but if it were bad it would not stop from defrosting would it ? it would just stop from terminating at temo right?

It would not stop defrosting if the timer motor stopped while in defrost yes but most systems have a heater hi limit to stop a melt down form happening. Also if you fan delay/defrost termination failed in the termination mode, it would trigger the defrost solenoid taking it out of defrost mode as soon as it went in.

[ryan1088]

LMAO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I thought you were just a straw boss. Ha.

[Fridge Repairer]

im going to guess the unit your working on is a very old semi hermetic compressor with weak valves. Let us know what you find Roy

[royd2]

as it turned out we changed the defrost terminators and the contactors. i think the contactors were sticking keeping the compressor running when it should have shut off

[steve36558]

Well on some larger systems the heater won't energize till compressor shuts off. Heater relay off aux contacts on compressor contactor. Your post #13 is a good starting point to check.

[steve36558]

Guages and electric meter will tell your problem.

[timebuilder]

Guages and electric meter will tell your problem.

I think he fixed it...

as it turned out we changed the defrost terminators and the contactors. i think the contactors were sticking keeping the compressor running when it should have shut off

[uniservice]

So,,,,you changed the DFT, the contacter, and the time clock,,,,,,Which part was faulty, or were all three bad??? I'd have a hard time billing a customer for parts that weren't needed, or maybe that's just me,,,,,,,,

[timebuilder]

Naw, it's not just you.

[valdelocc]

I'd have a hard time billing a customer for parts that weren't needed, or maybe that's just me,,,,,,,,

I'd have a hard time billing some customers for parts that were needed

[VTP99]

Naw, it's not just you.

X3

[3rdlaw]

i have seen pump down systems that utilize a relay that is energized by out side of compressor contactor , this is done to prevent heaters from coming on during defrost , which creates high current draw and can cause breaker to trip on single units . as far as pump down goes . low psi control should be set at approx 5psi . As
others have mentioned use gauges to verify . the schematic supplied should help out ... if none available trace wires these systems are usually very simple .