Original message
| Lancelot
 |  "Just to make sure"
, posted Thu 18 Sep 09:21  
Hi everyone, I was wondering what symptoms does a oversized compressor on a unit gives you? I have a 9000 btu water cooled unit and someone installed a 2 tons compressor in it. Both compressor and water cooled condensor are new, it's a package type unit, it broke down because of a condensor failure and when the guy put his gages on it, water was coming out of the lines ( oh that's bad news ) so he replace the condensor and compressor and he let me finish the job because he was goin on vacation...First of all, I would have never replace parts on a unit that had water in the system, I've done many vacuums and I couldn't pull lower than 1000 microns. I assumed the guy would've install the correct compressor but you know what they say about assuming? Should have checked it in the first place!!!
So finally, what are the symptoms in such a case!
Hope I've been clear in my post,
thanks guys
Pierre Paquin
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Replies:
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| Jojo98
| "Re(1):Just to make sure" , posted Thu 18 Sep 12:31:
I would be more concerned with the 1000 microns, you could still have water in the system. Was the system pressure checked with nitrogen?
I would think that the compressor will open on internal overload, because the A/C is going to try and move 2 tons of refrigerant through a 9000 btu line set, esentially dead-heading the compressor.
Basically it will not work for very long.
[this message was edited by Jojo98 on Thu 18 Sep 12:32] |
| | Lancelot
| "Re(2):Just to make sure" , posted Thu 18 Sep 12:46
Thanks for the fast reply friend, you are right about the 1000 microns, it is a major concern. I managed to make it work and although the water valve was open full stream, my high pressure was around 300psi with a low pressure of around 35 to 50psi with R-22 and yes I ran some nitrogen through the system to blow out the water, but as we all know it is very hard to dry out a system.
Thanks again
Pierre Paquin
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| | Schock Therapy
| "Re(3):Just to make sure" , posted Thu 25 Sep 21:41:
You are right in questioning repairs on a flooded w/c unit. You probably could have replaced the unit for less than repairing it. (even without the botched compressor replacement!) Having said that, you can get the moisture out of the system. I have used a Hot nitrogen purge. Make up a piece of copper tube to go between your nitrogen hose and the system, run the nitrogen slowly through the system while heating the copper with your torch. hot nitrogen will pick up more moisture than cool will. When you vacuum pump, change the oil frequently, and install an oversized filter/drier with flares so it can be changed out easily. (a moisture indicating sight glass is not a bad idea either.)
Your bigger problem is the oversized compressor. It will never work properly. Your head pressure is too high, and your suction is too low. You will have chronic freeze-up problems. You are going to have to put the correct compressor in if you don't want an endless string of call-backs.
Make sure you give your co-worker a smack for leaving you with his colossal screw-up!
It's only a shock if your not expecting it!
[this message was edited by Schock Therapy on Thu 25 Sep 21:44] |
| | Lancelot
| "Re(4):Just to make sure" , posted Fri 26 Sep 07:12
Thanks for the answer and thanks for the good idea with the heating of the nitro thing, I'm gonna try it if the problem happens another time. Finnaly I decided to buy a new system and save the parts that are recuperable and yes,I'm gonna smack my co-worker...and it's not the first time. We work in montreal, canada in a french speaking environment and we are french but I have the chance to speak and read english, my co-worker doesn't read english, heck I think he doesn't even read french for that matter ( just joking ) but he's not the guy who likes to read about the trade to get helpfull information. So his mistake was ASSUMING that the system was a two ton just by the size of it...so he forgot the main rule wich is: R.T.F.N. or Read The Freakin Nameplate...
I really do like this forum, I had quality replies, keep up the good work guys!!!
Thanks a million
Pierre Paquin
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