View Full Version : have CHAVS killed my compresssor???
totalacedude
19-12-2009, 02:07 PM
hi guys!
had my mum winge to me last night that the air con in her shop is not working! so today i went and had a look!
to my shock the outdoor unit which sits on a flat roof and is tied into the adjcent wall at the top had been forceabally pulled over!
the bad bit is my mum has been trying to run it on its side and the unit was coming up with compressor lock (which i now can understand why)
i have now stood it back up and tack welded the lid to the brackets, the pipes are totally fine surprisingly, i then re bent the metalwork and left for a few hours before power on.
The comp is not burnt out (used inductance meter to check all 3 phases) but still comes up with compressor lock, i can hear the pump try and come up to speed but trips after a few seconds, then tries a few more times then locks out with error.
What i want to ask you guys, is it worth leaving 24 or so hrs to see if it might be that the oil has drained into places it shouldnt, and what are the chances that it may ever live again!!
im asking cos im not a refrigeration engineer and seek the expertese of you guys.
cheers ian
multisync
19-12-2009, 03:35 PM
Almost certainly a stiffy. Leave it till tomorrow by all means but don't get your hopes up..
back2space
19-12-2009, 05:47 PM
BLoody chavs, what a disgrace they are!
If its the compressor thats gone its gonna be cheaper to buy a new outdoor unit really with a warranty!
Perhaps get a cage for the outdoor unit as well if its in access to chavs!
centrecipew
19-12-2009, 10:30 PM
Rather- Lets cage all the CHAVs instead!!!
taz24
20-12-2009, 02:44 AM
What are CHAVs ?
http://cornerstonegroup.files.wordpress.com/2007/05/chavs.jpg
taz.
^ Young layabouts with nothing else to do with their free time, after the dole money has been paid?
taz24
20-12-2009, 02:54 PM
^ Young layabouts with nothing else to do with their free time, after the dole money has been paid?
Oh yes :D
Cheers taz.
monkey spanners
20-12-2009, 04:41 PM
If its a heat pump unit, try and run it in the opposite mode to what it has been trying to work in eg. cooling instead of heating, hopefully this will get the oil back to the comp which is why its not working.
Still won't have done it any favours though...
totalacedude
20-12-2009, 05:03 PM
thanks guys!
yea if it is indeed knackered its going to be a new complete unit rather than compressor cos its now battered and bent, not much point spending out on it!
what ever the remerdy then yes i believe a cage is in order :mad:
i will try it in the other direction ie cooling and see what happens! but i dont hold out much hope!
another question guys?
would the pump be harmed if ran briefly in the other direction??
as i dont know how the compressors work if it has pulled oil up and hydroliced could it be driven opposite way to push oil back??
if so (as its an inverter) could i change 2 phases over and very briefly run it in in wrong direction and hopefully pushing the oil back!
is that possible as a very last resort? or will it just damage the compressor ??? (last resort = just before its condemmed any way)
just trying to cover any option
cheers guys
ian
nike123
20-12-2009, 05:11 PM
if so (as its an inverter) could i change 2 phases over and very briefly run it in in wrong direction and hopefully pushing the oil back!
is that possible as a very last resort? or will it just damage the compressor ??? (last resort = just before its condemmed any way)
just trying to cover any option
cheers guys
ian
Rotary and scroll compressors cannot work in wrong direction.
They don't pump in wrong direction.
Your best bet is to disconnect compressor from system, pour oil from discharge and try to blow it with dry nitrogen and than try to start it with keeping dry nitrogen supply at 5-10 bar.
taz24
20-12-2009, 11:03 PM
i will try it in the other direction ie cooling and see what happens! but i dont hold out much hope!
another question guys?
would the pump be harmed if ran briefly in the other direction??
as i dont know how the compressors work if it has
Don't confuse running the comp in the other direction and running the system in reverse.
The comp will always run in the same direction no mater what mode (heating or cooling) you have it on.
You will not be able to run the comp in reverse.
Cheers taz.
.
Don't confuse running the comp in the other direction and running the system in reverse.
The comp will always run in the same direction no mater what mode (heating or cooling) you have it on.
You will not be able to run the comp in reverse.
Cheers taz.
.
I'm sure when I was knee high to a grasshopper, I remember an engineer I was working with rewired the start and run capacitors on the compressor to give it a backwards kick.
Another trick he did was to temporarily connect another 240v supply to the compressor to give it a 480v single phase kick.
Don't suppose you can do this now with inverters..:eek:
Eggs
taz24
21-12-2009, 07:29 PM
I'm sure when I was knee high to a grasshopper, I remember an engineer I was working with rewired the start and run capacitors on the compressor to give it a backwards kick.
Another trick he did was to temporarily connect another 240v supply to the compressor to give it a 480v single phase kick.
Don't suppose you can do this now with inverters..:eek:
Eggs
You'r right Eggs the comp can be ran backwards if you know how, but it is not somthing I would recomend if you do not know what you are looking for.
Cheers ozone
.
Tell you what, when I think back on some of the tricks that fella pulled, jeeez it's a wonder he's still alive.
You should see how he recovers gas :eek::eek:
Butcher by name, Butcher by trade.
Merry Christmas
Eggs
totalacedude
22-12-2009, 12:44 PM
hi guys
right! at risking loads of ppl shouting 'COWBOY' at me here i go.... :)
i have solved this! proberbly by more luck than judgement!
bearing in mind im not an engineer, i looked at how scroll compressors actually work, now realised that what i think happened is that while the unit has been on its sidethe oil has drained to the scroll part.
as the unit is an inverter type and current limits (thus will not ripp the living $hite out of the compressor) i decided to turn off the conditioner and swap 2 phases over on the compressor.
i then ran conditioner till it kicked in the compressor and immidatally switched off! changed phases back ran it again and did this a few times and hey presto!!!!!
what i think has happened is it has picked up oil in the scroll and obv this wont compress!! (hydroliced)
running the compressor backwards has turned the scroll part inside it back just enough to expell the oil (a bit like squeezing a tube of toothpaste), and on the 3rd attempt it came to life and is now heating again!!!!
how lucky am i!!!!
this was a 'well its going to be scrapped' moment and thought what the hell ill try anything!
back2space
22-12-2009, 01:25 PM
I would perhaps run it in cooling for a while just to ensure all oil is out the way of the compressor...
Glad you have got it working and well done... seriously though what you have saved on a unit now invest in a cage for the outdoor unit as its not going to take much to bugger it up again...
monkey spanners
22-12-2009, 08:07 PM
Top bodging :D
Top bodging :D
On a serious note, Is it really bodging or are these skills now being lost to the new generation of parts swappers?
The first lesson I ever learned with fault finding non starting systems was to shove a screwdriver in the contractor and see if it runs, then work your way through the components using the "If in doubt, link it out" rule. Then you go through the whole system linking out components until bingo, the thing fired up. Probably not the safest way to do things, but it always found the problem.
Now it just seems to be swap the board, see if that does it.
Eggs
thebigcheese
28-12-2009, 03:29 PM
eggs i work for a smallish company (8 engineers) i was taught the link it out, its already broken method.
to be honest i dnt no how guys can call themselves engineers when they order all 3 boards and send the ones they dont need back
taz24
28-12-2009, 03:39 PM
hi guys
right! at risking loads of ppl shouting 'COWBOY' at me here i go.... :)
i have solved this! proberbly by more luck than judgement!
bearing in mind im not an engineer, i looked at how scroll compressors actually work, now realised that what i think happened is that while the unit has been on its sidethe oil has drained to the scroll part.
as the unit is an inverter type and current limits (thus will not ripp the living $hite out of the compressor) i decided to turn off the conditioner and swap 2 phases over on the compressor.
i then ran conditioner till it kicked in the compressor and immidatally switched off! changed phases back ran it again and did this a few times and hey presto!!!!!
what i think has happened is it has picked up oil in the scroll and obv this wont compress!! (hydroliced)
running the compressor backwards has turned the scroll part inside it back just enough to expell the oil (a bit like squeezing a tube of toothpaste), and on the 3rd attempt it came to life and is now heating again!!!!
how lucky am i!!!!
this was a 'well its going to be scrapped' moment and thought what the hell ill try anything!
If your a cowboy then your a good un :D,
In all honesty you have done only what most good engineers would of done.
at the end of the day the comp was not running and it is running now so well done.
taz.
Matt1982
13-01-2010, 08:06 PM
Hi guys. I am thinking of trying the same thing on a Mitsi puhzp6vha multi split tomorrow as the comp is seized. Does anyone know If I risk damaging the inverter board in doing so? Thanks
croc1774
14-01-2010, 12:24 PM
HI TAZ, are you sure this aint Hull football team :eek:
file:///C:/DOCUME%7E1/SHARON%7E1/LOCALS%7E1/Temp/moz-screenshot.png
fridge doctor
15-01-2010, 06:25 PM
Hi, what you did was quite in order. A few posts back someone said that it was possible to reverse a single phase compressor momentarily but they were not sure how. The answer is an 'ANNIE' which although I never owned one, I understand could often 'free off' stuck compressors by using it's own built in capacitors - I may be wrong here.
Certainly with 3 phase (which is what an inverter effectively is) changing any two phases will reverse the motor rotation. In the case of a 3 phase hermetic or semi-hermetic compressor it makes no difference at all which direction it runs, but as pointed out a scroll is completely different. If a mistake is made during wiring and the scroll runs in reverse believe me you will know it isn't right, but in the case of AC inverter compressors which might be described as demi 3 phase, there is no possibility of deviation from the manufacturers design because you are of course developing the demi 3 phase from a single phase supply, and so there is nothing to be reversed
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