Author Topic: Cu-200 supercool super isn't any more  (Read 3969 times)

Alberg 35

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Cu-200 supercool super isn't any more
« on: December 29, 2012, 07:52:31 pm »
I evacuated the system to 30" for 2 hours than added 134a to 6# on the low side and still got 3 blinks.
It only seems to want to run when there is about 20 psi at 55deg ambient temp and it is cycled manually to a vacuum of 20".
Now I know this is wrong, trouble is I'm stumped as to why it won't behave as it should.
There was a leak in the evaporator while underway a while back from knocking ice off and it was sealed up with thickened epoxy.
The freezer continued to work for the last year. Than it stopped cooling.
Having now read all the post on this site and read the archives I'm still baffled.
Yes I mucked with it, yes I added refrigerant initially without proper gauges and yes I know that is ill advised.
So now I'm trying to do it right and get it running properly.
I wanted to flush the system but honestly I was unsure how to correctly do that, I also wanted to drain the compressor oil and add the correct amount of pag oil to the system but I couldn't figure out how to do that either.
A thought I had was I introduced to much oil to the system when I added freon with oil initially and that may be causing the 3 blinks?
Any advice would be greatly appreciated.

As a side note I did purchase both of your books, just waiting for them to arrive.

Richard

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Re: Cu-200 supercool super isn't any more
« Reply #1 on: January 03, 2013, 11:17:00 am »
I am also confused with conditions you report. First do not add PAG oil to compressor as it uses POE Ester oil. It should not need to have oil changed besides to remove oil means turning compressor upside down and removing lines and this will not drain oil from complete system.

This does not make sense: “It only seems to want to run when there is about 20 psi at 55deg ambient temp and it is cycled manually to a vacuum of 20".

Compressor will run even if there is no refrigerant in system. Too much refrigerant will result in high amperage stopping compressor and a three flash troubleshooting LED.

A vacuum of 20 inches would indicate not enough refrigerant or refrigerant flow blockage. With correct amount of refrigerant normally contaminants or ice will stop refrigerant flow only at capillary tube orifice and compressor will keep running.  If blockage is anywhere in evaporator or low side of system compressor will continue to run.

I assume from your report you added oil to compressor How much was added and was it PAG oil?

When complete system is at ambient cabin temperature what is temperature and suction low side pressure before starting compressor?

Alberg 35

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Re: Cu-200 supercool super isn't any more
« Reply #2 on: January 06, 2013, 05:36:58 pm »
Thanks for the reply,
I initially added car 134a (i know i shouldnt have now)that also had oil in the can so I'm assuming oil went in as well.  My thought on this was would to much oil cause the compressor to have to much pressure and not run. I thought perhaps a flush of the system would clear any a plug if there is one and allow me to add the correct amount of oil if it was over filled.
I did not manually add any oil directly.
Please remember I know I messed up by doing the above.

The ambiance temperature at that time was 55 deg were the compressor sits in the compartment below decks and by cycling it manually I mean turning the temp nob on and of forcing the compressor to cycle until there is a vaccume on the suction side, which is the main issue at hand.
Doing nothing but turning the unit on, the compressor shows 3 blinks regardless of the pressure in the system. (Blockage ?)

Right now tha ambiant temperature in the compressor compartment is 55deg, the cabin temp is 65deg and the cooler is open to the ambiant air. Low side pressure is currently 26psi.

I did try to get the compressor to run unimpeaded by opening the valves on my yellow jacket Titan manifold between the low and high side but the 3 blink issue persisted.

Alberg 35

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Re: Cu-200 supercool super isn't any more
« Reply #3 on: January 06, 2013, 06:37:27 pm »
Another thought I had was, perhaps I didn't leave the system under vacuum long enough?
I didn't use heat last time either.
Would it be beneficial to vacuum the system again for a longer period of time and also use heat on the filter dryer and condenser?
My thought is remaining water droplets possibly freezing and blocking the capillary.

Richard

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Re: Cu-200 supercool super isn't any more
« Reply #4 on: January 07, 2013, 12:00:39 pm »

ANSWER

Question is what is currently causing 3 LED flash signal? Is it:
Epoxy you used to repair hole in evaporator?
Because added too much oil?
Too much refrigerant?
Contaminated refrigerant?
Air in refrigerant?
Error in gauge reading?

What I do know is there are two of the above items producing present condition of low suction pressure and a 3 LED signal. The only time I have seen this condition is when refrigerant flow is blocked between compressor and condenser. This was a result of a newly soldered line between compressor and condenser. A blockage after condenser with no more than correct amount of pure refrigerant will not overload system causing a 3 LED signal. I can not see how there can be a large vacuum and LED signal at same time.

Opening hand valves could have sucked in air increasing high pressure and amperage making things even worse. If you had both high and low pressure gauges connected why haven’t you reported high pressures.

Options open to you are limited short of buying a new complete system. Repairs to evaporators are short lived. Replacing evaporator in system’s present condition would not be advisable. If you new you actually added oil and how much some can be removed through high pressure port with vacuum recovery pump.

If blockage is within compressor/condensing unit a test with gauge set can be done to eliminate this complete unit. Remove center yellow hose from gauge set and install a self sealing cap on center gauge port. With both gauge valves closed connect one hose to its respective pressure port. Crack both hand valves for 2 seconds to bleed air out of gauge set then connect other hose to system. Now open both hand valves and turn on compressor. If compressor does not run there is a blockage in compressor/condenser or a mechanical lockup of compressor.  If a mechanical condition does exist in compressor you could confirm this by removing refrigerant till pressure is below 10 pis and try to start compressor.

If compressor will run with little refrigerant in system run it on a refrigerant vacuum pump long enough to reach 100 microns of pressure and holding it for two hours or 30 1nches vacuum for more than fours while keeping complete system at around 100 degree F with a hair dryer. This means even evaporator.