So I got a single phase scroll compressor from the job today. (It’s scrap, we replaced with a new one)
Instead of throwing it away I brought it home because I’m curious. So when I set the multimeter to ohms and touch any two combinations from common, start, or run the numbers jump. I thought I wasn’t getting a good connection so I attached alligator clips from my leads to the terminals and the same thing. Any insight?
Yes they do Jump under certain conditions. Scrape the pine or clean with emery cloth. Alligator clips wiggled give a better reading with a standard OHM meter.
Question, is the ohms only jumping at first and then go to OL? Constantly jump? How about from terminals to casing of compressor?
It jumps normally from some high number to a lower number. I understand that’s because of the inrush of voltage the meter sends out. So after it settles from that it goes to another number and continues to drop and then back up to a different number.
It never goes to OL. It constantly jumps, yes. From terminals to casing is OL. (I scratched away through the paint to make sure I’m on the metal of the casing)
Yes they do Jump under certain conditions. Scrape the pine or clean with emery cloth. Alligator clips wiggled give a better reading with a standard OHM meter.
So I got a single phase scroll compressor from the job today. (It’s scrap, we replaced with a new one)
Instead of throwing it away I brought it home because I’m curious. So when I set the multimeter to ohms and touch any two combinations from common, start, or run the numbers jump. I thought I wasn’t getting a good connection so I attached alligator clips from my leads to the terminals and the same thing. Any insight?
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when you cranked up the new compressor was there any issues ? or did the replacing go smooth
So I got a single phase scroll compressor from the job today. (It’s scrap, we replaced with a new one)
Instead of throwing it away I brought it home because I’m curious. So when I set the multimeter to ohms and touch any two combinations from common, start, or run the numbers jump. I thought I wasn’t getting a good connection so I attached alligator clips from my leads to the terminals and the same thing. Any insight?
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My first inclination is the meter is either cheap, low battery, or set on the incorrect sensitivity level. My second inclination is who cares? The compressor is good or it's bad. Do you need to know anything more than that? It's not like you're going to re-wind the motor. Resistance is a great diagnostic tool, but you either have it or you don't. If the numbers don't add up then they don't add up. Your $200 Fluke meter isn't going to tell you anymore than good or bad and it doesn't have to. Let's face it. We don't get called out when things are working properly. Were you to megg an operating compressor and told the owner the tolerances are off...but the unit is still cooling, are they going to take your word and replace the compressor? My folks have a unit that eats capacitors annually. I talk to their hvac guy on the phone every spring. He says the megger says the compressor is bad. I tell him every year to replace the capacitors and leave it go. This is probably going on 8 years now.
Officially, Down for the count
YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET
I know enough to know, I don't know enough
Why is it that those who complain the most contribute the least? MONEY CAN'T BUY HAPPINESS. POVERTY CAN'T BUY ANYTHING
My first inclination is the meter is either cheap, low battery, or set on the incorrect sensitivity level. My second inclination is who cares? The compressor is good or it's bad. Do you need to know anything more than that? It's not like you're going to re-wind the motor. Resistance is a great diagnostic tool, but you either have it or you don't. If the numbers don't add up then they don't add up. Your $200 Fluke meter isn't going to tell you anymore than good or bad and it doesn't have to. Let's face it. We don't get called out when things are working properly. Were you to megg an operating compressor and told the owner the tolerances are off...but the unit is still cooling, are they going to take your word and replace the compressor? My folks have a unit that eats capacitors annually. I talk to their hvac guy on the phone every spring. He says the megger says the compressor is bad. I tell him every year to replace the capacitors and leave it go. This is probably going on 8 years now.
Changed the batteries and the numbers are holding steady now...
I’m doing this for personal growth and understanding. Ive learned a lot from this thread already.
Zero ohms would mean he is shorted to ground. With a typical multimeter he would want OL (no continuity). If he gets a megger he will need to learn how to use it. Not sure what good a megger is for residential work. If I was him I would invest in a good HVAC multi meter.
Zero ohms would mean he is shorted to ground. With a typical multimeter he would want OL (no continuity). If he gets a megger he will need to learn how to use it. Not sure what good a megger is for residential work. If I was him I would invest in a good HVAC multi meter.
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Originally Posted by Bruce Melton
