One of the fastest growing tech channels on KZread. Keep it up!

Using the term perfect path to describe zero resistance is a great way to help visualize what's going on.... Love this channel

Sir I am very proud of you getting your channel.

Great video man, see you guy’s on Friday

Another great video guys!

i will be watching and liking all of your videos very on point!! subscribed!!

Great video for Sunday. Bert you're working hard on Sunday ^_^. Take a day off on Monday ^_^

On most of the old "pumpkin" style compressors the wiring diagram is on the black door that you took off to get to the wiring.

Leg to leg readings are still useful, just not for determining a short. If you have an open reading between run and common, there's still a problem.

@carloscervantes618

4 жыл бұрын

That's right, I always check leg to leg lol

@lupojacobo9892

4 жыл бұрын

I agree with and disagree with the teacher 👍🏽😁

@jfmc2581

4 жыл бұрын

Yeah but that wouldn't trip the breaker would it?

Very nice video

Great Video! Most of the time, yes short to ground agreed. I just thought I'd add that last year I had a compressor that was not shorted to ground and I had the correct resistance across each terminal, but the compressor still tripped the breaker IMMEDIATELY. No hum, no rattle, no sound whatsoever. I was a little nervous to change the compressor without understanding why it was tripping the breaker....Changed the compressor and it's operated excellent since then.... I don't consider myself an expert and I never understood why the old compressor tripped the breaker. Just thought I'd share this in case someone runs into the same situation.

@jonnymac31

4 жыл бұрын

What model meter were you using?

@guitarhvac

4 жыл бұрын

John McMaster Fluke 117 if I remember correctly.

@jonnymac31

4 жыл бұрын

@@guitarhvac got ya. I have seen guys using meters that don't have the range and will read OL so they think it's good. Lots of guys have the 902 where I work. It only goes to 10K.

@ForHim_orAgainstHim

4 жыл бұрын

guitarhvac Hey that’s a great concern you have brought to light from your experience! I had a similar experience where the 3 winding resistance measurements were right on. The hvac program I attended in the past had 4 compressors the professor had us troubleshoot. This one compressor, the windings ohmed out BUT we megaohmed it with a fluke and it was measuring a clean grounded condition ( compressor terminal to ground, not terminal to terminal). So even if a compressor ohms out on a ( start terminal to common + run terminal to common = start terminal to run terminal ) it can still be grounded. The best way to test a compressor’s electrical condition is with a good mega ohm meter.

@ForHim_orAgainstHim

4 жыл бұрын

guitarhvac My theory on why compressor can pass the ohm test but fail the mega ohm test is this: when testing for ohms the multimeter is only putting out an amount of voltage that will measure resistance in a load but will not pick up a short through the insulation of the internal windings due to the low amount of voltage. So we would need more voltage/ electrical pressure ( a LOT more!!) to be able to detect if there’s any breaks in the insulation. A megaohm meter puts out 500 or 1000 volts DC. We would put one lead onto ground and the other one on a terminal. The test will read O ohms if there’s a ground ( a leak through the insulation arching to another winding, the windings aren’t physically touching but the short is actually an arch to ground). If the windings are good, the tool will go up semi gradually to 0L because there is no where for the voltage to pass to due to no weak spots or breaks in the insulation. ( kind of like a standing nitrogen test on a system to see if there’s any leaks; you need a lot of pressure, at least 250psig, which is large amount of pressure to detect breaks in the refrigerant lines, coils, compressor or brazed connections.)

Great job explaining this! 👍🏼

Nice job and video

Love Bert, but needed that chart and translation at the end!

Like your plyers

very nice..

Thanks I learned something new

From what I have learn from your previous videos I would not unplug at the compressor first. I would trace wires to source and check there for proper readings or for indicators where to go next. If there is no shorts to chassis ground, no opens but compressor shows some resistance and wires check good. Then I would add a new capacitor and fire it up. If it doesn't turn on, compressor is bad if it has enough freon for it to turn on.

The meter he's referring to, the "MEGGA METER" is commonly called a Megger. Megger is a brand name but means a meter that can produce between 250 up to 1000 volts DC. The 9 volts produced by a typical digital ohm meter is often times not enough to detect a problem.

Are you shorted to ground or neutral ? It depends on local wiring code, if neutral and ground are tied together. Isolated grounding is better at protecting control circuity if a motor does short to ground.

Great info. like your videos wish i could enroll in your school. Too bad i live in Texas.

@EastDallasKicks

3 жыл бұрын

Same here

Great

Have you a link to the Copland flow chart?

If I come across a unit tripping breakers I go straight into disconnecting compressor then if it still goes off then on to condenser fan etc If stays on then I then get some readjngs off the compressor to put on my work report

Knowledgable video

Always check capacitor first

great video Bert. I need a meg ohmmeter . What do you guys use at Kalos ?

@TheWpruden

4 жыл бұрын

I purchased PCE ITM-20 multimeter. It has a built in insulation tester. 50v, 125v, 250v, 500v and 1000v. For $339.00 current price. It's ip67 rated!! Spot on with my fluke 87v on practically all readings!! It's better than spending $700.00 on that fluke 1587. Yes I know but flukes hold their accuracy. I just could not turn this down. My 87v is home on the shelf. I do carry my fluke fc 902. PCE Instruments are in Florida. I have a 2 year warranty. www.pce-instruments.com/us/index.htm?id=google-us&_artnr=5887877&_p=339&_pmode=0&_pbexkey=73&_date=20200203011856&_pbhash=cd6eb0ffc47108a0c322b7fef000a7d5c0aaea87e0dfac4522bc81d70a4b9148&gclid=CjwKCAiAyeTxBRBvEiwAuM8dnWqSt85vC-rLxya45-R3XGcFcz3WlHlWche3zn8_Sw7Vovoa7i2SQBoCqdcQAvD_BwE

informative

How do you feel about the high dollar fluke meters to check insulation, terminal connection to ground...?

@HVACS

4 жыл бұрын

i will try to answer these in Q/A video

My instructor said we should unplug the wires on the capacitor and contactor that go to the compressor and test for shorts there to the ground terminal. He said that way you isolate it and don't keep blowing fuses. Is there any downsides to doing it that way as opposed to taking off the condensing fan and testing from the compressor itself? Thanks for all these videos?

@HVACS

4 жыл бұрын

I will try to answer your question in Q/A video

So same goes with a car a/c clutch not engaging? It cold be a loose or bad dirty ground? Tried everything exect this I notice the ground on the a/c compressor is very dirty and greasy and the screw is loose also....If I clean and tighten it should my clutch engage? I already can jrump streight power from the relay and it comes on and blow cold...Replace relay switch with new one and replace high a/c switch too....Thinking I have a bad ground is what prevents the clutch from going on like a weak pour ground???? Any help please much appreciated.

motor windings if one winding shorts on the motor or transformer is bad even if the compressor checks and shows some resistance. The resistance you measure only proves that the windings are not open.

11:52 - Does that mean he made a 'common' mistake?

UEI for mega ohms works for me

hi to the author can you be still used a gas from grounded compressor? if recovered and filtered?

Hi some compressors has U V W terminal，is it the same way to test，thanks

If my breaker is not tripping and the unit appears to be functioning properly, is there still a possibility that I have a shorted compressor or did my technician measure incorrectly?

Cant find that megometer on amazon, can you put up a link plz

We're did you get that metter

Could someone explain how he used the mega here? Where did he attach the leads? What did he check with the hand meter while using it?

@captainmigs1655

3 жыл бұрын

I believe he had one lead on the dish charge line service valve where he cleaned it and then tested each leg on the compressor itself

So...the compressor has an internal short?

What if the ground in the disconnect is not connect will they shorten the circuit as well?

👍

Idk.... those windings definitely are common down here bro...

GEEZ , the guy helping me at AC place their place not open today or tomorrow AND I need to ask him again something . He said on blower motor if I disconect the cool terminal wire on circuit board and connect the bottom black wire to cool terminal that ( this is what I'm not sure what he said and needed to talk to him ) if it works ( or doesn't ) that means board is bad NOT the motor ?? OR is it the other way around ?? And yes replaced capacitor . Still the same barely running the blower not full speed and shuts down after a while with new capacitor

I got a grounded 2 year old carrier LG compressor today at work. what would cause a somewhat new compressor to short? I looked at the customers nest app and the system wasnt running long, like 40min to 2-3 hrs a day

@caru3257

2 жыл бұрын

I found one today. It blew the fuses at the breaker panel, 200 amps. Install procedures more likely, i.e. vacuum, not flowing nitrogen while brazing, bad capacitor, etc.

Plz to understand how to use compressor test meager meter

My compressor start and stop so i get error "overheat ".I measure resistance and its ok.

Can I buy a megometer at Secco?

I can't visualize how a system would operate with the compressor removed/isolated. When you reset the breaker where does all the vapor/oil go?

@maggotthemadman8142

2 жыл бұрын

Nevermind I was assuming isolating the compressor meant taking it right out of the system.... *doh!!* Still all piped in which makes a lot more sense.

Use continuity function carefully and know your meter. For example one meter I have will give reading and tone from 0 to 40 ohms, reading only from 41 to 300 ohm and infinity reading above 300 ohm. Can't hear the tone anyway so never use it.

First thing I do is meg all of the compressors and condenser fan motors. Use a Real megger.

The "megohmmeter" is really testing insulation resistance measured in megaohms. The "Hand meter" is high impedance so you'll never be able to get a good reading. You're dumping double the nominal voltage down it to check for electrical leaks is how I would explain it. I thought you blokes would of used similar terminology being wind plumbers?

I like the video, however don't agree with the first thing. Never reset a tripped breaker right away. I learned that the hard way on my very first summer as an apprentice. Damn thing blew the terminals right next to me. CHECK FOR SHORTS FIRST then you can go ahead & reset it.

Make sure your ohm meter is capable of reading millions of ohms. Some fluke clamp on meters only read in thousands of ohms.

Sooooo...you didn’t look at the capacitor first?? Seriously??

Just don’t see the reason of using the megger when your normal meter saw the short. I would understand it on long wire runs or going through something very high resistance. Just seems like a redundant check at that point. Thorough testing y’all are doing though, which is more then A LOT of techs from different companies I had to go behind. I swear, some people where blindfolds when they check this crap, they shouldn’t be allowed to touch the stuff.

It’s was Saturday and I was wiring in my generator for the hurricane that was coming the next day. I walk by the a/c and I hear a pop. The fan is running so I just keep going. A hurricane is coming. My wife comes out 10 minutes later and says there isn’t any cold air. GREAT. my unit has 2 large caps, I never knew why. One of them is clearly bad. I have 45 minutes to drive to the a/c store before they close. I take the part and he says he has it and it’s a hard start. Great, I install it and flip the switch on and it immediately smokes but the compressor does start.. it freaks me out so I pull the outside breaker. A/c or finish the generator ❓. I decide generator and call an a/c company. The guy checks and says the compressor is grounded. He DOESNT check with the wires off. He tries to sell me a 10k a/c, which nobody has because of COVID. I need a 4 ton. My wife tells a friend at church and he says don’t do anything I’ll send a friend. He comes and disconnects the wires and checks, it’s not grounded. He disconnects the relay and presses in the contractor, instant a/c. Knowledge is power which is why I watch these videos. This was the first time I didn’t fix it myself. Oh, the hurricane turned and missed us, but now the generator is wired up and ready for the next one. The a/c runs fine without the hard start. I don’t know why it was there.

Would the common terminal have continuity to ground normally? Or do u test all three to ground run , start and common to ground in looking for the short

Hey if y'all got extra tools (meggomeaters) send me one... ssx34, sman4'$, etc..... I got some cool stuff already so, any of those will be greatly appreciated... I like appion too.... i dont have anything appion....

Not a good idea to keep resetting the breaker. Should check for a ground before just resetting a breaker. This will create a worse burnout condition

Bk

Very confusing and disappointing video. In trying to isolate whether the short is in the wiring or the compressor … the field tester says “it’s very obvious now”. … without explaining what’s obvious, whether he had determined the short was in the wiring, or compressor.