Compressor Cycling off.

[liftbear]

Hi,
I'm new to the forum, and was wondering if someone could offer me some tips/suggestions. I recently just installed a new compressor to a split system. As I'm charging the system it shuts off after about 2 minutes, and kicks back on after about 5 minutes. Why is this happening?

[Fridge_expert]

Hi,
I'm new to the forum, and was wondering if someone could offer me some tips/suggestions. I recently just installed a new compressor to a split system. As I'm charging the system it shuts off after about 2 minutes, and kicks back on after about 5 minutes. Why is this happening?

Is the equipment equipped with a low or high pressure switch? You could have put in too much refrigerant and it's cycling on the high pressure safety. Are there non condensables in the system (Some forget to release and evacuate the nitrogen charge after leak test)? Are the air handler and condenser fans running? This info is all important. The compressor could be cycling on internal overload too so could it be running too hot?

[liftbear]

I believe its cycling on internal overload, but i'm not sure why. The system needs about 5lbs 15oz. I have weighed in about 4lbs and 8ounces in so far. Definitely no nitrogen in the system, I ran a vacuum on the system for about 2 hours, and am putting in clean freon, not the original freon. All fans are also running.

[Fridge_expert]

I believe its cycling on internal overload, but i'm not sure why. The system needs about 5lbs 15oz. I have weighed in about 4lbs and 8ounces in so far. Definitely no nitrogen in the system, I ran a vacuum on the system for about 2 hours, and am putting in clean freon, not the original freon. All fans are also running.

What are the clearances of the unit, it needs to be so many inches away from the walls and obstructions and prevailing winds could affect head pressure too. Bad placement could have caused the initial compressor failure. Also, measure your voltage And amperage at the contactor, voltage should be within 5% of nameplate, Low voltage causes higher amperage And nuisance trips oF the Overload and possibly breaker.

[jvillehvac]

Did you replace the capacitor or check the old one?

[socotech]

What are your pressures when compressor/unit cuts off?

[socotech]

Did you replace liquid line drier? Does this unit have a txv?

[liftbear]

This Unit is at an apartment complex that has 9 other heatpumps setup the exact same way. Its about 2 feet away from the wall, and about 85 degrees outside no wind.
Originally when I came out to this unit. I had a blown fuse. I replaced fuse, then realized I still wasn't getting power to the system. So I checked breaker, and realized I had a bad breaker. I replaced breaker and then the system started working. About 10 minutes of running I heard a leak. The leak was coming from the compressor where the wires were connected. I assumed the fuse and breaker had gone bad due to the compressor going bad. So I did a complete compressor change out. During the charge of the new compressor, the compressor cuts off after only 2 minutes of running.

[liftbear]

Did you replace the capacitor or check the old one?

The old one still has the correct MFD

Did you replace liquid line drier? Does this unit have a txv?

Yes liquid line drier was replaced, and yes this unit has a txv.

Thank you for all the replies!

[Fridge_expert]

Did you replace liquid line drier? Does this unit have a txv?

Oh yes you can't forget this one! Restrictions Of any sort can cause high head pressure or compressor overheating.

[liftbear]

My head pressure is at 185psi when the compressor kicks on, but the compressor kicks off after only 2 minutes or less.

[liftbear]

The system needs about 5lbs 15oz. of R22. I have weighed in about 4lbs and 8ounces of R421 in so far.

[Fridge_expert]

The system needs about 5lbs 15oz. of R22. I have weighed in about 4lbs and 8ounces of R421 in so far.

You're using A different gas? O,,o

My fault..it's an r22 replacement

[liftbear]

You're using A different gas? O,,o

My fault..it's an r22 replacement

Yes its an r22 replacement and I made sure I ran a good vacuum also

[SBKold]

You got power problems id bet. What's the amp draw on common. Also common and run together and start only?

[Tommyz23]

Have you checked amp draw? If the other ones posts blew out, it sounds like it may have been running hot as well. Filter?

[liftbear]

Filters are clean. I will hop into the attic today and check how clean the coil is. But assuming all that is good and the amp draw is too high, what could possibly be causing it?

[socotech]

Does this compressor have the preformed terminal connector (as found on many copeland scrolls) or is it the type that you wire each lead individually?

If it is the preformed connector, look at your female spades closely. Sometimes they get loose and cause a bad terminal connection.

[liftbear]

Does this compressor have the preformed terminal connector (as found on many copeland scrolls) or is it the type that you wire each lead individually?

If it is the preformed connector, look at your female spades closely. Sometimes they get loose and cause a bad terminal connection.

Yes its a copeland that you just basically plug in. I'll check to make sure its not loose also. Thank you for the suggestion!

[socotech]

The old one still has the correct MFD

Yes liquid line drier was replaced, and yes this unit has a txv.

Thank you for all the replies!

Are you sure the compressor is even pumping for two minutes? You said MFD on capacitor is correct, but did you verify with a meter?