How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Phil Your Own Question
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 8435
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
23932409
Type Your HVAC Question Here...
Phil is online now
A new question is answered every 9 seconds

I just installed a zr42k5epfv800 comp. in a customers heat

Customer Question

I just installed a zr42k5epfv800 comp. in a customers heat pump on Friday. After the vaccuume held for four hours I weighted the charge in. The comp. did not sound right and it would not pump. The charge leveled out on my gages and did not move. This is the second comp. I have installed in this same unit in a week. The first one shorted to ground in three days. I have installed a lot of comp. in my life time, this is the first time I have had this kind of problem. Am I over looking something. Does copland ship their comp with oil in them.
Submitted: 2 years ago.
Category: HVAC
Expert:  Phil replied 2 years ago.
Welcome! Your question will be answered in detail. UP to 48 hours step by step coaching on diagnosis & repairs $38 additional.
Copeland and all other mfgr ship their compressors with oil in them..
Tell me what you use for a vacuum gauge, we can go from there.
.
Customer: replied 2 years ago.
I used my standard vacuum pump and my standard a/c gages.
Expert:  Phil replied 2 years ago.
Hello again,
you really need a micron gauge to check vacuum and leaks properly by the pressure method. however what you are doing has worked for the previous 50 years. (soap bubbles combined with an electronic leak detector is best or a halide torch on refrigerants with chlorine atoms in them).
Minor leaks would not cause the problems you have seeing.
It is rare that a compressor is bad out of the box... however if you have been in the business a long time and you say the compressor didn't sound right, there very well may be a problem with it.... unless it is a 3 phase unit and it was running backwards. (those make very loud racheting noise in that case)
Lets make sure you are on 230v single phase or 230v 3 phase... and what phase the compressor is rated for.
We can go from there.
.
Customer: replied 2 years ago.
The data sheet that came with the comp. states that It is a 230 volt single phase comp.
Expert:  Phil replied 2 years ago.
Hello again,
You have quite an unusual situation there.... when you checked the grounded compressor, was that done with all of the wires disconnected from it? tell me where each probe of your meter was when you did that check... and if the read was the same as touching two test probes together or no, Please be as overly specific as you can.
tell me in great detail what you mean by 'the charge leveled out on my gages and did not move' please.
We can go from there.
Customer: replied 2 years ago.
The first comp. tripped the breaker after the second night, however there were storms in the area and the power to the house went off and on several times during the night. I placed my leads on each terminal to make sure there was not a short between the windings. I then checked each terminal to ground. I found the short between common and ground. After weighing in the charge and starting the unit my gages showed 100 psi on the high and low side.
Expert:  Phil replied 2 years ago.
Thanks, ***** ***** to be sure that when you did the electrical checks on the compressor, that all of the wires on the compressor were **removed..
if they were removed, then the compressor is burned out. Lightning strikes can cause such damage and also blow the run capacitor up.
-----------
If the 100 psig low and high side reads, occurred when the compressor was actually running, and you verified that by measuring amperage on the Common wire that runs to the compressor...then the compressor valves are bad ....or the reversing valve is stuck half way between heating and cooling mode... or you had left one or both of gauge valves open on your service gages when reading the gages (that bypasses the low side to the high side.)
-----------
Try operating the reversing valve by having someone else change the thermostat settings between heat and cool and setting the temperature to extremes in each case ..... as you stand by the unit and listen for the characteristic gushing sound as the 4 way valve reverses.
let the system run for 60 seconds before the thermostat is switched between heat and cool.
Tell me if there is a 5 minute time delay or not.
We can go from there.
Customer: replied 2 years ago.
There is a delay in starting, the comp. plug was removed and I took my readings from the comp. terminals. ON the second comp. my gages were closed. The comp will only run for about 30 seconds before turning off. I'm getting 223.6 volts to the comp. Its like the internal over load in opening. This may be a new problem. Yesterday it was not doing that.
Expert:  Phil replied 2 years ago.
Thanks
Use a clamp around type amp meter to check the amps on common to the compressor first, then start, then run... do that in the 30 seconds before it shuts off. There could be a failed connection at the plug in on the compressor.
I need the amp readings and the full load amp number from the unit name plate for the compressor (FLA or RLA, not LRA)
.
Customer: replied 2 years ago.
It's drawing 64.3 amp at start up on common and start, 5.1 on run. I checked the plug and it checked out all right. I ohm out the comp. and it shows a short between the windings. I wired the plug that attaches to the comp as follows start to l2, common to l1, and run to the herm side of cap. as it shows in the diagram. Did I do something to short this comp.
Expert:  Phil replied 2 years ago.
Thanks.
64 amps is locked rotor amps, indicating the compressor is mechanically frozen, or that its run capacitor is bad not connected.
I want to tell you something about brain function...if you use abreviations of any sort, even known abreviations. it causes the brain to abandon its linear thought process, a process needed, as it tries to decide what among many options an abreviation stands for.
It has to decide if 'comp' is short for compressor, or compare, or comprehensive or whatever... the more abreviations the more muddled it gets, even though you and I are fully aware of what 'comp' means here... it gets exponentially worse with the more abreviations used.
Compressor motor terminals are C, S and R... (common, start and run) I do not know what you mean be the |2, and |1 terms. I have not seen that so far in 51 years working on these units.
---------
For now to avoid confusion, I need the amperage reads on all three wires that run to the compressor when it tries to start, if there is no amp read on the start (S) terminal wire running to the run capacitor, we have a bad run capacitor.
Let me know, we can go from there.
.
Customer: replied 2 years ago.
start on the compressor is drawing 64.3 amps, common on the compressor is drawing 64.3 amps, run on the compressor is drawing 5.1 amps. The three wires coming from the compressor is wired as follows, start is wired to the line 2 side of the contactor, common is wired to the line 1 side of the contactor, and run is wired to the hermetic side of a dual capacitor. The capacitor has a rating of 55uf for the hermetic side and 5uf for the fan side. I have checked the capacitor and it is fine. Above you stated that start went to the run capacitor please verify this. The diagram shows run winding to go to the capacitor. The capacitor is also rated for 370 volts.
Expert:  Phil replied 2 years ago.
Thanks for the excellent detail.
The compressor is wired incorrectly.... the condenser fan may be wired incorrectly at this point also.
Line 1 runs directly to C on the compressor and also to the C terminal on the run capacitor.(not the herm terminal on the capacitor... C is the middle terminal on the capacitor.) Let that soak in for a while.
The Herm terminal on the capacitor runs to S on the compressor (that is the start winding in the compressor.
Line 2 on the contactor runs to R (run winding) on the compressor.
---------------
Attach a well focused, well lit photo of units wiring diagram, taken close up and straight on... using the 'attach files' link at the bottom left of your reply box, so that I can verify that.
We can go from there.
----------
Please rate my work so far, so that I can justify spending time above and beyond what is allowed for by a simple answer.
We are on the honor system here. If you need anything else, just let me know. You can continue asking follow-up questions at no additional charge.
Customer: replied 2 years ago.
Phil, I think you are right, I wired the run wire to the capacitor, I did so because of the color coded wiring diagram that is on the back of the plug. I believe that is why the first compressor shorted out. I will notify Emerson and let them know of the error. Thank you so much for all of your help and I will give you an excellent rating.
Expert:  Phil replied 2 years ago.
You are welcome, here is the ratings box!
.
Customer: replied 2 years ago.
Phil is the type of a/c tech we all strive to be. He helped me solve a problem that was a brain twister. Thank you just answer for having Phil as one of you experts.
Expert:  Phil replied 2 years ago.
Thanks, ***** ***** however you should still send me a photo of the wiring diagram so that I can mark it up if necessary.
When you replace the compressor capacitor or any other part you should always have an amp meter on it in order to detect any failure to start properly before it burns something up, it takes compressor 30 to 60 seconds to burn. so a 5 or 10 second trial (that we call a smoke test as an old joke) is what we do.
I begin any new part change with a one second smoke test, then if nothing blows up, a 5 second test, if that seems fine, then I turn it and run amperage and refrigerant pressure tests.
If you have any doubts about the correct wiring, send me the diagram, and I help you review it.
.