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garboy
21-08-2012, 09:06 PM
HI, I am involved in a site that has a Pqry 407c,unit connected to 8 indoors. Its been giving problems for a while. Basically about half of the units seem to work perfectly most of the time while the other half work for maybe 20 mins after doing a virgin re-start and the gradually the air off temp rises and rises. There is no leak on the system as i have carried out a pressure test. The unit never shows a fault but the compressor does not seem to ramp up, even though some of the indoors are well over their setpoint.
Could there be something wrong that the compressor is not ramping up?
I have checked all the addresses, b,c box etc and cant find anything wrong. Even if i turn off the 4 "good" units the cooling out of the other 4 is not good at all. Im 90% its not SOG but could be wrong
Any help will be greatly appreciated as im starting to look stupid in front of the client!
Thanks

install monkey
21-08-2012, 09:41 PM
read all the sensor values off the outdoor unit- could be a pressure transducer or sensor giving a rogue value but not actually indicating fault but just incase i found a service manual - 12 meg- struggling to upload it
http://www.mediafire.com/file/smt62uoq7mtq68p/PQH~RY-P200
does take a while to open but it worked ok

stufus
21-08-2012, 10:11 PM
There was a problem with the LP transducers on them units ,reading out of calibration ,causing the bypass to open to keep the back pressure up .
Turn everything to fan only and leave it for an hour , then use the dip switches or better still the maintenance tool to verify hp , lp and p1 , p3 are all reading the same value if one's out thats your problem.
Cheers
Stu

garboy
22-08-2012, 09:09 AM
I checked the lp and hp transducers with the maintenance tool, but they all seem ok, i have come across some of these having the lp put by 1 bar, but not this one!

garboy
22-08-2012, 09:11 AM
Thanks a million for the manual, should come in handy!