troubleshooting 3phase compressor please help

[bubba_v2008]

i have this compressor a tecumseh AV190TT-045-S7

460V 3PHASE 60HZ
5 TON R22 compressor hermatic compressor

here is my question this is a replacement compressor installed a month ago everthing was done correctly to my knolage flush high acid filter drier and vaccum what its doing is nothing!!!!

ive checked the windings and none are open and none are grounded
ive got the correct voltage coming to the compressor each leg and leg to leg
ive tried to check the amp draw but its not pulling anything or even trying to come on ive never seen this before in my life

the only thing i could think of is on the windings from when i ohm ed each leg had the same continuity i believe it was around 4.3 i am kinda rusty to the hvac industry do to taking a different job but still should be able to figure this out they shouldnt have the same continuity should they???? or is that ok on 3phase im not real sure and anything would be appriatated

im 99% sure the compressor is bad but there is still that little bit bothering me

[aircent1]

Ohm phase to phase, 3ph. Should all be very near the same
Each leg at comp terminals to gnd, 0L at ALL phases.
If contactor is in ......line side to load side power is passing and compressor still is not running.
Compressor is bad.
Actually check while contactor is closed line and load sides to ensure power is passing.

Last thing to check, there's no internal overload.....see schmatic drwng.....
What type of unit??

[chill out hvac]

long story short, Feel the top of the compressor.. If its smoking hot its out on overload.. Leave it off overnight, start it up in the morning. If you have 460v on every combo going into the compressor, write up the compressor..

[bubba_v2008]

it is a carrier 10ton rooftop package unit when i ohmed phase to phase they were pretty close to the same and none were grounded and i had full power going to the unit with the contactors closed i just never seen one do that they usally hum or will have a winding open or somthing just figured it would alleast try with the windings good and power to the comp. thanks alot for the help just making sure im not crazy

[bubba_v2008]

yeah i know when a compressor is in overload it will have a open leg i belive common to start right?

[chill out hvac]

God only knows whats going on there, Some compressor just break internally and seize up.. If its not out on overload replace the compressor..

[bubba_v2008]

yeah thats all i could figure thanks for the help i just never seen one do that before so i figured i would check around on the internet and see if anyone else has

[XcelTech]

bubba add your email to your profile <but not on the forum page> and i will send you some info.

[bubba_v2008]

Doin it now thanks

[XcelTech]

You got mail

[bubba_v2008]

Thanks alot man

[captain123]

yeah i know when a compressor is in overload it will have a open leg i belive common to start right?
Three phase compressors don't have common, run or start windings, each winding has the same resistance, that's why the ohm readings should all be about the same and that's why there's no run or start cap.

[jpsmith1cm]

Where and when did you measure voltage?

3 phase is different.

I'm pretty sure the compressor is NOT bad.

[bubba_v2008]

Had to be bad I replaced compresser today and it's working fine

[frideman1]

let compressor cool down shut off overnight or disconnect from contactor and let condensor fans stay running. if nothing is open reverse polarity by switching 2 power leads it may start if it is stuck . then watch system maybe something else is going on .

[bubba_v2008]

I tried all of the above tried reversing polarity but it was not trying to do anything and was not in thermal overload I replaced compresser today and it was working fine so hada b the compressor I let it sit with the disconnect off all last night plugs it in this morning and nothing sweated in my new comp and everything else and it purred like a kitten

[timebuilder]

Hmm.

[timebuilder]

Had to be bad I replaced compresser today and it's working fine

Well, at least there is a happy ending.

[johnbeck1000]

I don't know if you can look at the old compressor but if your meter doesn't go above 999 ohms then you might have missed the short to ground and should use a better meter to see. The reason I know this is because it happened to me but I couldn't figure out why this compressor was having problems and then I went and grabbed my high end meter and it picked up a short to ground, I learned my lesson.

[chuckcrj]

Well, at least there is a happy ending.

Unless it fails again in a month....................

[timebuilder]

Unless it fails again in a month....................

Shhhh! :angel:

[maxster]

simple 3 phase check you want a dead short on the winding T1..T2...T3 at the compressor terminals or the bottom of the contactor and no shorts Ts to ground or copper lines this with disconnect off.if you have cold oil you can actually read a grounded winding to copper line warm it up and the ohms start to change to show open to ground

[bwd111]

Well, at least there is a happy ending.Why dont you ask him what the temp and pressure should be . :grin2::grin2::grin2::grin2::grin2::grin2::grin2:

[HvacCraftsman]

Was Voltage actually checked to the peckerhead of the compressor? Not underminding your Diagnosis but it's something that i've learned to check just to be sure.

[bubba_v2008]

Well thanks for everyone's help!!!!! I checked the voltage and it was correct I checked it again Friday with the new compressor and everything looks good thanks for all the help if I could I'd check the old compresser again but it was a warranty so it's gone now it very well could have been because I didn't use my fluke meter used the fieldpiece which usually works great I don't know but hopefully it last longer than a month this time lol or I need a find a different career

[hvactech80]

Three Phase Scrolls need to run in 1 certain Direction--Could be going the wrong way.