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Mike.duford

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I recently gained employment with new plumbing /heating company with a long and reputable history in a new town and i am now the only tech doing hvac work for them. Said company has a sister non profit that takes disabled vets on guided hunts and uses their own walk-in freezer to store the meat for processing. This freezer was previously dismantled and being prepped for relocation when the tech that was performing the work ceased employment with company, leaving the job in the middle undone with no notes or status recorded whatsoever!!

I will humbly state that my experience is primarily in residential and light commercial with very little to no experience with refrigeration!! This is all very new and have no one to approach or speak with in person, that being said i like to believe i have enough common sense and intelligence to self educate to some extent

Scenario-freezer is located i n back of warehouse with compressor located on top of freezer, absolute minimum length of line set is used at a total of no more than 7’ of 3/4” and 7’ of 3/8” line
The one bit of info i did receive was that the unit had a very small leak and had not been addressed

Copeland compressor model-EAVB-021E-CAV-800
SERIAL-14A65711R

The leak was located on one of the capillary tubes coming off of the low side. Now i am aware that i probably shopuld have replaced the capillary tube with brand new but instead was able to seal with a bit of welding( is this acceptable or bad practice)

After testing with nitrogen and confirming that the leak had been sealed i vacuumed it down to 563 microns.

Having no information of any kind for charging and proper pressure ratings i began to slowly add refrigerant until i started seeing positive results and was stoked when this freezer responded exceptionally and dropped to 22 degrees and was purring like a good Copeland kitty!!


Then all of a sudden the compressor stops all of a sudden but the inside fans continued to run as if under normal operation
I still have power to all places requiring it but compressor will not return to function

I am at a complete loss as to what it could be like i said this is very new to m,e and any positive feedback will be greatly appreciated
 
Few questions ....

Did you notice the sight glass on the side of compressor , that is for oil level , and was it half full of oil ?

Does the unit have a Freon sight glass in the liquid line ?

Did you check run and start caps ?

Does this unit have safeties .... like a High Pressure safety , and if so does it have a push button you can reset ?
 
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Its not welding its brazing!

What cap tube? In the condensing unit, evaporator, controls, x-valve?

NO, you can not just braze a Cap Tube. Score it and break in. cut a short piece of 1/4" tubing to use as a sleeve, insert both ends and pinch closed. Braze completely closed!

Where is this camp?
 
What were the operating pressures at the time you got it up and running good?

Are you certain it was not in defrost, Then again that may be why you were asked about the CF status when it died.

Did you measure the voltage at the compressor terminals?
 
Its not welding its brazing!

What cap tube? In the condensing unit, evaporator, controls, x-valve?

NO, you can not just braze a Cap Tube. Score it and break in. cut a short piece of 1/4" tubing to use as a sleeve, insert both ends and pinch closed. Braze completely closed!

Where is this camp?
He may be referring to the distributor tubes as cap tubes, for some reason this is a common misconception.

I've repaired distributor tubes that were damaged by control wiring rub-through ect. on the fly. But who hasn't.
 
Sounds like you were undercharged and over heated the compressor, what refrigerant, what are your pressures, does it have receiver and sight glass? Not to sound like a a$$ but we need as much info as possible we are not there. There is a sticky at the top of this thread. Please read and give us as much info as possible, and we will do our best to help get you in the right direction good luck
 
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He may be referring to the distributor tubes as cap tubes, for some reason this is a common misconception.

I've repaired distributor tubes that were damaged by control wiring rub-through ect. on the fly. But who hasn't.
I think we all have touched up a rub mark on cap tubes without splicing. In reality the braze is stronger than pipe according to Harris :cheers:
 
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I still have power to all places requiring it but compressor will not return to function
Are you sure you "have power to all places requiring it"? Is there actually 230V at the compressor terminals, or do you really have no idea and are just making up statements that aren't true?

Freezers are complicated. There's a lot to figure out for somebody who doesn't have any experience with working on them. Everybody has to start somewhere though.

Let's start with the basics. Most walk-in freezers work on the pump-down principal, with no direct wiring between the evaporator and the compressor.

When the defrost timer and thermostat are both calling for cooling, power will be sent to the indoor fans (which will themselves be controlled by their own little thermostat which allows for a delay for them to turn on after defrost) and the solenoid valve, which is turned on and off by the thermostat.

When the solenoid valve is energized to open, refrigerant pressure will start to increase up at the condensing unit. Then the low pressure switch at the condensing unit will "cut-in" and send power to either a compressor contactor or relay (or sometimes directly to the compressor if it's amp draw is small enough) to turn on the compressor and the condenser fans.

I usually start my diagnostics at the low pressure switch. If there's 230V across both wires, it means that the switch is open. That means that there isn't enough refrigerant pressure built up for the compressor to turn on (or perhaps that it's cap-tube is plugged up with whatever you thought you were "welding" with). You would then compare what the cut-in and cut-out settings are to what you are actually seeing on your low-side gauge, to see if the low pressure switch is actually doing it's job, or if it might be bad.

If the voltage across the low pressure switch wires is zero, and each of those wires to ground is 120V, then the switch is closed and trying to tell the compressor to turn on. If you follow the power from there and find that there's no high pressure switch or open compressor overload or anything else stopping the power from getting to the compressor, and you actually have 230V between C and R at the compressor terminals, then you might have a bad compressor.

Or it could be something going on with the starting components, but that's a whole 'nother complicated ball of crap to have to try to explain, so I'm leaving it at this for now?

So, is your pressure switch closed and do you actually have power going to the compressor and condenser fan motor?
 
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It could have went into defrost , and his evap fans wired wrong ....

Did the Condenser fan stop too ?
 
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What is your defrost timer set at? How many cycles (4-5x) a day at 30?45 minute Times…?

Are the defrost heat strips wired in correctly?

The cap tube I’m thinking you attempted to repair correctly is on the evap after the txv..

What temp is the cold control set at near the evap to open the LLV? Freezers are typically in the -10 to -5 sensed to see 0 degrees

What was the pressures /SH/SC you saw during charging it? (407c/R22/R404a))

The evap fans should be running unless it’s in defrost
 
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