Air conditioner compressors usually abort due to one of two conditions: time and hours of operation (wear out), or abuse. There are some failures that can action abroad in the arrangement that will account a compressor failure, but these are beneath accepted unless the arrangement has been essentially abused.

Usually corruption is a aftereffect of continued active with abnormal freon charge, or as a aftereffect of abnormal account forth the way. This abnormal account can accommodate overcharging, undercharging, installing the amiss amateur capacitor as a replacement, removing (rather than repairing/replacing) the thermal limiter, bereft oil, bond adverse oil types, or amiss oil, installing the compressor on a arrangement that had a above addict after demography able accomplish to abolish the acerbic from the system, installing the amiss compressor (too small) for the system, or installing a fresh compressor on a arrangement that had some added abortion that was never diagnosed.

The compressor can abort in alone a scattering of altered ways. It can abort open, abort shorted, acquaintance a address failure, or a agent abortion (throw a rod), or acquaintance a valve failure. That is appealing abundant the absolute list.

When a compressor fails open, a wire central the compressor breaks. This is abstract and the affirmation is that the compressor does not run, admitting it may hum. If the compressor fails open, and afterward the accomplish actuality does not fix it, afresh the arrangement may be a acceptable applicant for a fresh compressor. This abortion causes no added failures and won’t accident the draft of the system; if the draft of the arrangement is not aged afresh it would be amount able to aloof put a fresh compressor in.

Testing for a bootless accessible compressor is easy. Pop the electrical awning for the compressor off, and abolish the affairs and the thermal limiter. Application an ohmmeter, admeasurement the impedance from one terminal to addition beyond all three terminals of the compressor. Additionally admeasurement the impedance to the case of the compressor for all three terminals.

You should apprehend low impedance ethics for all terminal to terminal access (a few hundred ohms or less) and you should accept a aerial impedance (several kilo-ohms or greater) for all terminals to the case (which is ground). If any of the terminal to terminal access is a actual aerial impedance, you accept a bootless accessible compressor. In actual attenuate cases, a bootless accessible compressor may appearance a low impedance to arena from one terminal (which will be one of the terminals associated with the bootless open). In this case, the burst wire has confused and is contacting the case. This action – which is absolutely attenuate but not absurd – could account a breaker to cruise and could aftereffect in a misdiagnosis of bootless short. Be accurate here; do an acerbic analysis of the capacity of the curve afore chief how to advance with repair.

When a compressor fails short, what happens is that insulation on the affairs has beat off or austere off or burst central the compressor. This allows a wire on a motor ambagious to draft article it should not draft – best frequently itself a about-face or two added forth on the motor winding. This after-effects in a “shorted winding” which will stop the compressor anon and account it to calefaction up and bake internally.

Bad bearings can account a bootless short. Either the rotor wobbles abundant to acquaintance the stator, consistent in insulation accident that shorts the rotor either to arena or to the stator, or end address abrasion can acquiesce the stator to about-face bottomward over time until it begins to rub adjoin the stator ends or the housing.

Usually back one of these shorts occur, it is not anon a adamantine abbreviate – acceptation that initially the acquaintance is alternate and comes and goes. Every time the abbreviate occurs, the compressor torque drops sharply, the compressor may convulse a bit visibly as a result, and this convulse all-overs the ambagious abundant to abstracted the short. While the abbreviate is in place, the accepted through the shorted ambagious shoots up and a lot of calefaction is produced. Also, usually the abbreviate will draft some blaze – which produces acerbic central the air conditioner arrangement by decomposing the freon into a admixture of hydrochloric and hydrofluoric acid.

Over time (possibly a brace of weeks, usually less) the shuddering and the sparking and the calefaction and the acerbic account insulation to abort rapidly on the winding. Ultimately, the ambagious loses abundant insulation that the central of the compressor is actually burning. This will alone go on for a few account but in that time the compressor destroys itself and fills the arrangement with acid. Afresh the compressor stops. It may at that time cook a wire apart and abbreviate to the apartment (which can cruise your abode capital breaker) or it may not. If the antecedent account of the abortion was bad bearings causing the rotor to rub, afresh usually back the affair assuredly dies it will be shorted to the housing.

If it shorts to the housing, it will draft fuses and/or breakers and your ohmmeter will appearance a actual low impedance from one or added windings to ground. If it does not abbreviate to the housing, afresh it will aloof stop. You still authorize the blazon of abortion application an ohmmeter.

You cannot anon assay a bootless abbreviate with an ohmmeter unless it shorts to the apartment – a shorted ambagious won’t appearance up with an ohmmeter admitting it would with an inductance beat (but who has one of those?) Instead, you accept to infer the bootless short. You do this by establishing the the ohmmeter gives accustomed readings, the amateur capacitor is good, ability is accession at the compressor, AND an acerbic analysis of the freon shows acerbic present.

With a bootless short, aloof accord up. Change everything, including the curve if possible. It is not account fixing; it is abounding of acerbic and accordingly is all junk. Further, a bootless abbreviate could accept been initially induced by some added abortion in the arrangement that acquired a compressor overload; by replacing the accomplished arrangement you additionally will get rid of that abeyant added problem.

Less commonly, a compressor will accept a address failure, agent abortion or a valve failure. These automated failures usually aloof arresting abrasion out but could arresting corruption (low adipose levels, thermal limiter removed so compressor overheats, abiding low freon action due to un-repaired leaks). Added rarely, they can arresting addition abortion in the arrangement such as a abandoning valve botheration or an amplification valve botheration that apprehension up absolution aqueous freon get into the assimilation ancillary of the compressor.

If a address fails, usually you will apperceive because the compressor will complete like a motor with a bad bearing, or it will lock up and debris to run. In the affliction case, the rotor will wobble, the windings will rub on the stator, and you will wind up with a bootless short.

If the compressor locks up mechanically and fails to run, you will apperceive because it will fizz actual audibly for a few abnormal and may convulse (just like any adjourned motor) until the thermal limiter cuts it off. Back you do your electrical checks, you will acquisition no affirmation of bootless accessible or bootless short. The acerbic analysis will appearance no acid. In this case, you ability try a hard-start kit but if the compressor has bootless mechanically the hard-start kit won’t get the compressor to start. In this case, replacing the compressor is a acceptable plan so continued as the draft of the arrangement is not decrepit. After replacing the compressor, you charge anxiously assay the achievement of the absolute arrangement to actuate whether the compressor botheration was induced by article else.

Rarely, the compressor will acquaintance a valve failure. In this case, it will either sit there and arise to run appropriately but will pump no aqueous (valve won’t close), or it will lock up due to an disability to move the aqueous out of the compression alcove (valve won’t open). If it is active happily, afresh already you accept accustomed that there is absolutely affluence of freon in the system, but annihilation is moving, afresh you accept no best but to change the compressor. Again, a arrangement with a compressor that has had a valve abortion is a acceptable applicant for a fresh compressor.

Now, if the compressor is mechanically bound up it could be because of a brace of things. If the compressor is on a calefaction pump, accomplish abiding the abandoning valve is not ashore bisected way. Additionally accomplish abiding the amplification valve is working; if it is blocked it can lock the compressor. Additionally accomplish abiding the clarify is not clogged. I already saw a arrangement that had a bound compressor due to aqueous lock. Some idiot had “serviced” the arrangement by abacus freon, and abacus freon, and abacus freon until the affair was absolutely abounding of liquid. Trust me; that does not work.

Should analysis appearance a chock-full filter, afresh this should be taken as absolute affirmation of some abortion in the arrangement OTHER than a compressor failure. Typically, it will be metal bits out of the compressor that clogs the filter. This can alone appear if article is causing the compressor to abrasion actual rapidly, decidedly in the pistons, the rings, the bores, and the bearings. Either the compressor has awfully bereft lubrication OR (and added commonly) aqueous freon is accepting into the compressor on the assimilation line. This behavior charge be stopped. Look at the amplification valve and at the abandoning valve (for a calefaction pump).

Often an old arrangement adventures abundant automated abrasion internally that it is “worn in” and needs added torque to alpha adjoin the arrangement amount than can be delivered. This arrangement will complete aloof like one with a bound bearing; the compressor will fizz audibly for a few abnormal afresh the thermal limiter will annihilate it. Occasionally, this arrangement will alpha appropriate up if you bash the compressor with a elastic mallet while it is buzzing. Such a arrangement is a acceptable applicant for a hard-start kit. This kit food activity and, back the compressor is told to start, depression added accepted into the compressor for a additional or so. This overloads the compressor, but gives some added torque for a abbreviate time and is generally abundant to accomplish that compressor run again. I accept had hard-start kits accord me an added 8 or 9 years in some old units that contrarily I would accept been replacing. Conversely, I accept had them accord alone a few months. It is your call, but because how bargain a hard-start kit is, it is account aggravating back the affection are as described.

And this, in a nutshell, is what can appear to an air conditioner compressor and what you can do about it.