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What am I doing wrong??

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#21 ·
meoberry said:
I have had two different compressors on different units show to ground twice in the past and supposedly another company has come along and got it running.
How is this possible? Both compressors would blow a fuse as soon as power was applied. Both of them took the lowest setting on my ohm meter to even show the ground. I always check with all wires off the compressor to all three legs.:eek:
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I'll throw another possibility out there because it has happened to me. I once found a grounded compressor and quoted replacement. A few hours later the customer called in saying another company had gotten it running and was raising hell with the dispatcher. When the dispatcher called and told me I was just a couple streets over and drove back by the building only to find the company that supposedly got it running hoisting a compressor up the side of the building. I guess some people just like drama. Anyway, the justice in it all was about 12 years later we did several systems for a builder and guess who the owner of the house turned out to be? Yeah, that owner who called in. Maybe I was wrong, but I couldn't help but bring it up one day when I was over there for something. He turned white and then claimed he didn't remenber it....:D.
 
#22 ·
meoberry said:
Now that makes sense. Appreciate the input.
But I did find that this new meter has a higher ohm scale than any of my older ones did.
I went back to another compressor that showed had a slight ground and and installed a new fuse. Sure enough it fired up and started cooling. Shut down and tested again ground still there on the highest setting on meter. Found four blown fuses by disconnect. This is on the same condo and same floor about 6 doors down. Checked all connections from compressor to main breaker panel. I believe these compressors have a breakdown in the insulation on the windings. I am pretty sure that they where not vacuumed down. I used to work for the company that installed them and know from experience they do not use vacuum pumps.
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Not unusual for a compressor to run with a slight ground. I've seen them run showing 30 Mohm to ground many times, but always note that because they probably won't run long. Moisture in the system can cause those type of readings and also rainy and wet days can make our instruments show crazy readings. In the original post those were blowing a fuse immediately, so something bad was up. The mention of a meggar is a good idea, but you have to check the compressor and note the readings everytime you are out there in order for it to give you any real idea of what is taking place. Most times on smaller equipment the owner will opt to just let it run til it dies, but at least you can look like a genius when you predict it.
 
Discussion starter · #25 ·
heaterman said:
As a side note, I hate Edison based fuses as protection devises. No substitue for breakers.
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Ahmen. These condos where built about 6 years ago. I don't know who the electrical contractor was and don't wan't to know. But they installed over two thousand of them. I quit carrying the blasted things a couple of years ago. In fact I had to get our electrical supply house to special order me some they didn't even stock them anymore. I called 4 different supply houses trying to find them. I found two at a hardware store and they knew how hard they where to find they didn't even use vaseline.:eek:
 
Discussion starter · #26 ·
I finally figured out what is wrong after I condemned two contacors with bad coils after reading 30 volts at the coil. Called the place where I bought my meter 8 months ago and told them they could have it back.:mad:
 
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