Broken SS advice, possibly ceased compressor?

[Splave]

Continuity is the dot with sound wave like projections to the lower right hand corner. Make sure you're there when you check for continuity.

Yeah that's what I used. It beeps loud and shows those values

[Hondacity]

The Continuity test is the one on the lower right that looks like a dot with sound waves. The one just above it I believe is for microfarads, but give me a little bit to verify. Im a bit busy now, hehe.

ever heard of diodes?

[Stewie007]

ever heard of diodes?

Whatever, I was just telling him which one you use to test for continuity. And I didn't see a microfarad setting but wasn't sure what the symbol was. Go bash somewhere else.

Edit: I think its wonderful how you completely ignored my post just after that.

[Stewie007]

Yeah that's what I used. It beeps loud and shows those values

This really makes me wish I were right there to help you. I'm all over the place here because I'm not able to physically get my hands on the unit, hehe.

Anyways, if the compressor has a short circuit, the meter would show OL for Open Loop. The fact that you are getting readings shows that electricity is flowing, but its beeping because its below 120 Ohms (I am just assuming that the loud beep was a "buzz"). Take a look at the website below, its a good reference.

http://www.hobby-hour.com/electronic...multimeter.php

I know I am editing the hell out of my posts, but just bear with me. Still looks like a bad compressor.

[Splave]

thanks I will go ahead and get a new compressor ordered, ebay the best prices around? no junkyards really around here

[Hondacity]

runmc or sdumper might have some spares...

[Buckeye]

Just getting the compressor is the easy part.
It must be brazed back in, tripple vac'd and then charged with a load tester on it.
The Filter/Drier should also be replaced.

In fact if it was acid that destroyed the comp there is a good chance that stuff is all through the unit. I have no idea how to clean that stuff out, others might know if its even possible.

[runmc]

In fact if it was acid that destroyed the comp there is a good chance that stuff is all through the unit. I have no idea how to clean that stuff out, others might know if its even possible.

You are right on Bill. I had a compressor fail on a condensing unit about two weeks ago. The windings in the compressor had shorted and killed it. The A/C man put a new condensing unit in and added a filter/drier to the suction line as well as the liquid line to clean out contamination.

[Hondacity]

in short an hvac guy is needed + proper replacement parts

@ron

i thought you were hvac cert'd?

[Stewie007]

You are right on Bill. I had a compressor fail on a condensing unit about two weeks ago. The windings in the compressor had shorted and killed it. The A/C man put a new condensing unit in and added a filter/drier to the suction line as well as the liquid line to clean out contamination.

I second that.

Generally, the filter size should be one size up for your capacity rating. It will maximize the absorption of contaminants in the system. Depending on the severity of a burnout, the unit will have to be run and then checked for acid. If acid still remains, then the system has to be evacuated and the filters replaced again until there is no acid in the system. I am not completely familiar with the clean-up procedures before installing the new compressor. It may involve blowing the system out with compressed nitrogen.

[ZenEffect]

stewie, splave's about capacitor result, wouldnt that be a result of the cap slowly discarging into the meter? From what he is stating it starts at 0 then jumps to 20meg then lowers. sounds like the behavior you expected + slow discharge. i bet if there were a voltage reading, it would slowly decrease as well... like when you discharge a cap using a resistor.

the low impedience is telling me that the winding is shorted to ground somewhere. (same as with when you check a transformer on say like an amp... either the varnish on the windings goes bad and it shorts resulting in much lower impedience than expected, or it breaks and you get no reading)

hvac guy is only needed for filling and testing. the rest of the parts do not require a liscence. you can get a small nitrogen bottle at harborfreight for like $100 (i think its pre-filled too) to purge, you can use MAP gas to braze. then you need guages to pressure test, vaccume pump, refridgerents, schrader valve, etc.... mabye it is best to get a hvac guy to do it since there is no investment in tools... unless you want to venture into phase change cooler building (which im all for... another builder on the block would be awesome, this section has the most interesting pics anyways)

stewie, every time i replaced a compressor for a refridgerator, or ac unit, we would always purge the system with nitrogen. I believe its SOP for most places, but since ive only worked at 1 company doing it, im not 100% about it. purging also helps to remove any excess water vapor that could potentially block the cap line as well. as far as removing acid from the system... you got me but it seems to be a common enough problem that im sure there is a off the shelf solution of chemicals or something.

[Stewie007]

stewie, splave's about capacitor result, wouldnt that be a result of the cap slowly discarging into the meter? From what he is stating it starts at 0 then jumps to 20meg then lowers. sounds like the behavior you expected + slow discharge. i bet if there were a voltage reading, it would slowly decrease as well... like when you discharge a cap using a resistor.

The way it sounded to me, he tested his capacitor backwards. The jump to a higher voltage reading followed by a slow discharge seems to suggest that there was a little bit of energy still in the capacitor to start, and then the energy began to discharge. Since the circuit is one way as we know, it seemed logical to me that he might have had the leads reversed. He should have gotten a rise to infinity without any ability to discharge the energy. Otherwise, we know that the capacitor is bad. If he tested it with the leads in the correct place, then it is discharging as you said; that shouldn't happen, correct? Without a retest, I wasn't willing to rubber stamp it.

the low impedience is telling me that the winding is shorted to ground somewhere. (same as with when you check a transformer on say like an amp... either the varnish on the windings goes bad and it shorts resulting in much lower impedience than expected, or it breaks and you get no reading)

As far as the low resistance, I am definitely inclined to agree. I believe that moisture in the system eventually formed acid, which in conjunction with the oil formed a sludge and attacked the enamel and eventually shorted the windings. In his case he got a very low reading while testing resistance. However, not being a guru, I tend to question myself without being able to get my hands on the thing, hehe. I had the thought in the back of my mind that I was gonna be wrong. I suppose he could finalize the verification by touching the compressor casing and then each lead to the motor and if it beeps with any of them then he surely has a short to ground, which is what I would do in the event that I got funky readings whilst testing the leads. I forgot to suggest that..... having a hard time concentrating these days (long story)... hehe

stewie, every time i replaced a compressor for a refridgerator, or ac unit, we would always purge the system with nitrogen. I believe its SOP for most places, but since ive only worked at 1 company doing it, im not 100% about it. purging also helps to remove any excess water vapor that could potentially block the cap line as well. as far as removing acid from the system... you got me but it seems to be a common enough problem that im sure there is a off the shelf solution of chemicals or something.

If it isn't SOP it should be. Breaking a closed system with air would seem counter intuitive, but given what I've seen on the manufacturing side, people don't always follow standard procedure. Most of the modifications or repairs that I do are the result of defective compressors from a supplier or fractured tubing, so there isn't going to be any need for cleaning. My thoughts there come from many lengthy discussions with engineers and from research of such problems. There are methods of flushing the system, but I can't attest to their usefulness in this situation.

He probably doesn't want to spend the 100s of dollars on the equipment so paying somebody else to do it is probably a good idea... hehe. In this case, doing it yourself is generally much more expensive (unlike most car repairs). But we do it ourselves because we love building things and taking them apart... I don't know about you, but I can't be happy if I'm not at least designing a new system.... ^_^

[Stewie007]

http://www.uri.com/is-bin/INTERSHOP....0&OnlineFlag=1

This is a good example of a good FD to use for system cleanup after burnout.

[Splave]

Anyone able to fix this If I send to them seems all the local HVAC places are busy and or scared of the unit or should I just look to have a brand new one built

[Stewie007]

They won't remove the charge or recharge it? I would assume then that they are too busy. It wouldn't be very difficult to remove the charge and then recharge it based on the scale readings they took during evacuation (which you've got to do if you want to make sure you aren't overfilling the recovery cylinder).

You could do the work yourself with a few tools that come to think about it aren't that pricey. The nitrogen cylinders are available at HVAC stores and the 120 or so you pay for the cylinder is a deposit that you can get back when you return it (just keep the original receipt proving that you got it from them). If I had more time I could provide you with a step by step for replacing a compressor, of course if you don't mind waiting for a little bit I could do just that.

I've got a lot of experience replacing compressors (larger 25 ton scrolls and such, but still a similar process). In fact, your job is much easier.

The thing about building a system is that you can have control over how easily you can perform service. I've designed my water chiller with suction service valves that will allow me to change key components easily by isolating charge to the high side using a receiver and removing the components (flare fittings if they are too close to service valves). However, replacing a compressor is a lot easier, and you can take care to ensure proper clean-up with the appropriate tools.

That filter I showed you has a good acid absorption capability, but its less effective with moisture. Great for burnout cleanup, though. Its the carbon (charcoal core). As stated before you would also want to install a suction filter during cleanup. So after you run the unit for a while, the refrigerant would have to be recovered and the filter replaced (at this point the suction filter would probably be unnecessary), and the unit recharged.

The thing is, during all of this acid tests should be performed to determine just how many times you need to change the filter. For a small system one cleaning cycle is probably all that you need.

[ZenEffect]

Anyone able to fix this If I send to them seems all the local HVAC places are busy and or scared of the unit or should I just look to have a brand new one built

shipping to someone who is capable of performing the re-charge *more important than replacing the compressor, any hvac shop can do that* + cost of new compressor + shipping back is still less than the cost of a new one.

[Stewie007]

shipping to someone who is capable of performing the re-charge *more important than replacing the compressor, any hvac shop can do that* + cost of new compressor + shipping back is still less than the cost of a new one.

Unless the postal/fedes/ups people use it as a soccer ball! hehehehe

[Splave]

^ this, stewie do you have time to fix if i send to you

[runmc]

in short an hvac guy is needed + proper replacement parts

@ron

i thought you were hvac cert'd?

I have a Universal certifications which allows me to buy refrigerants and do hvac work but replacing the burnt out condensing unit was at one of my rent houses and I didn't have the time to fix it. The job had to be done right away. Sorry for the off topic Splave.

[Stewie007]

If I had time, I would. I've been itching to work on something.

[Splave]

this is the compressor
http://www.ra.danfoss.com/TechnicalI..._ed402o202.pdf

[Stewie007]

Resistance, auxiliary winding [Ohm] 3,20 Ohm
Resistance, main winding [Ohm] 0,60 Ohm

Retest and repost your resistance readings on your windings...... I'm just curious here...

[runmc]

Anyone able to fix this If I send to them seems all the local HVAC places are busy and or scared of the unit or should I just look to have a brand new one built

Here you are.

[Splave]

hehehe that looks "fixed" to me so excited bro thanks for the pic

[Splave]

Resistance, auxiliary winding [Ohm] 3,20 Ohm
Resistance, main winding [Ohm] 0,60 Ohm

Retest and repost your resistance readings on your windings...... I'm just curious here...

left side hovers around .5 ohms? and left 3.0 ohms?