Defective TXV causing compressor overload cycling ?
Can a bad TXV cause the compressor to cycle on overload ?
What would the pressures exhibit if it was the txv causing the problem?
I recommended to a friend to pull and weigh the charge and pull a vacuum and recharge, because its a completely new system, CU , Evap coil , Linesets and txv, all new.
I didnt do the install it was another friend of his.
This must be a tough one ? Nobody , not even the pro's on this forum can offer any insight on this problem ?
Mostly because you haven't given any real information about the problem.
Originally Posted by Bobe5531
Saturated suction temp
Saturated liquid line temp
Indoor ambient temps, Db and WB of return and supply
Delta across indoor coil
Outdoor ambient temp
Compressor amp draw
Condenser fan amp draw
Delta across outdoor coil
Evap above or below condenser, and how far
AHRI matched system or not
Good point . I dont have that data, yet. I guess I was just speaking in general terms as what a tech might see the system doing or not doing if there was a defective TXV.
Originally Posted by beenthere
A TXV can fail in more then one way. So there are several different symptoms you could see, depending on what is wrong with the TXV.
Apply for Pro membership. Lots of info in the Pro only forums.
I just saw a 40 ton RTU do this last Friday.
What "overload" is the compressor cycling on?
Does the condenser fan motor stop or start when the compressor cycles on the overload?
Is the amp draw exceeding the FLA rating?
Is the compressor shell temperature exceeding the maximum rating?
Originally Posted by Bobe5531
The conventional view serves to protect us from the painful job of thinking.
Assuming that you mean the internal overload/temperaure protection device is opening after a period of hour or hours running. If the expansion valve is causing this indirectly it is because the superheat is too high. The valve is not open enough to allow sufficient cooling refrigerant to the compressor. If it is a basic residential unit this will usually happen if the SH is over 20 degrees. I used to have a lot of this problem when I worked in the desert, not so much in a cooler climate.
Heres the only info I have on this one until I check it out myself :
Originally Posted by Poodle Head Mikey
All new evap coil linsets CU. Installed about 5 weeks ago and has had this problem from day one.
He claims that the comp is turning on and off on high pressure overload constantly. Sometimes it stays running for an extended period sometimes not. The guy is an electrician and claims that voltage is correct as well as amp draw. His buddy who installed it is supposedly 30 yr Hvac tech. The buddy suggests that it may be overcharged. He said he had two guys working on it at he same time.
I know this is very vague and can see why you guys would need much more data to make any suggestions of a solution. I will try and follow up as soon as I get more info.
Oh, cycling on high psi not compressor overload.