Factory/dealer screwup

[hillbilly1]

Customer bought a brand new 25 hp three phase 480 volt air compressor. Paid the distributor/dealer an extra $380 for them to convert it to 480. Has two different nameplates, one says 220 volt, while a sticker was added “440 volt”. Bumped it to check rotation, all good. Runs for two days, the electronic overload relay explodes. Salesman wants a picture of the starter to see if his guys actually converted it. Ok…then I seen how he could tell, they brought all of the motor leads to the bottom of the starter, where they split out the windings, and changed the taps, wrapping them in some tape. They forgot to change out the electronic overloads!

 

[petersonra]

They forgot to change out the electronic overloads!

Why would they care what voltage is used?

 

[Joethemechanic]

Just curious, is the dealer here in the USA?

Mitsubishi, Air compressors and Tuna all from one place lol

 

[LarryFine]

Why would they care what voltage is used?

Electronics, like in a GFCI.

 

[petersonra]

Electronics, like in a GFCI.

overload relays just do not normally care what the voltage is.

 

[hillbilly1]

overload relays just do not normally care what the voltage is.

These are powered off the line voltage, haven’t seen any like these before. Usually the electronic ones are powered by the current flowing through them. Apparently this is an issue with this manufacturer, they knew exactly what happened.

 

[hillbilly1]

Just curious, is the dealer here in the USA?

Mitsubishi, Air compressors and Tuna all from one place lol

Yes, it is a US dealer.

 

[hillbilly1]

Customer bought a brand new 25 hp three phase 480 volt air compressor. Paid the distributor/dealer an extra $380 for them to convert it to 480. Has two different nameplates, one says 220 volt, while a sticker was added “440 volt”. Bumped it to check rotation, all good. Runs for two days, the electronic overload relay explodes. Salesman wants a picture of the starter to see if his guys actually converted it. Ok…then I seen how he could tell, they brought all of the motor leads to the bottom of the starter, where they split out the windings, and changed the taps, wrapping them in some tape. They forgot to change out the electronic overloads!

Sorry, sticker says 460 volt!

 

[Joethemechanic]

Yes, it is a US dealer.

Everybody is turning over help so much that nobody has any experienced help anymore. Youthey send them into areas with wouldn't believe some of the maintenance guys I have to deal with. They don't know a delta from a Wye, couldn't do ohm's law on a single loop DC circuit and don't even begin to understand steam. But they get sent into places with 13.8 switchgear and to see what's wrong in a boiler house with four 500 HP boilers

 

[hillbilly1]

I’m going through all of it tomorrow before I re-energize it, including checking for any faults in the motors. Don’t like any boom-booms! LOL! Plant owner is nervous because we need the compressor working for the new machine he just dumped $300 grand into! (Just the machine alone, not counting the new 1600 amp service and all of the electrical to go with it)

 

[hillbilly1]

Sat down this morning and went over the wiring diagram, they don’t even know what they have. The component that blew up was a phase loss relay! Thought it didn’t make sense in the brief time I looked at it.

 

[Joethemechanic]

Sat down this morning and went over the wiring diagram, they don’t even know what they have. The component that blew up was a phase loss relay! Thought it didn’t make sense in the brief time I looked at it.

Because overloads weren't good enough I guess

 

[ptonsparky]

A phase loss relay for 240v certainly wouldn't like 480. Surprised it ran as long as it did.
Then again I've seen ice cube relays with contact ratings of 240v being used to switch 480 successfully for years.

 

[Joethemechanic]

A phase loss relay for 240v certainly wouldn't like 480. Surprised it ran as long as it did.
Then again I've seen ice cube relays with contact ratings of 240v being used to switch 480 successfully for years.

It really should stay closed unless you lose a phase or have somebody screws up the phase order, shouldn't it?

I could see it being useful for protecting mechanical equipment from reverse rotation. But we've run air compressors for half of forever with just overloads

 

[ptonsparky]

It really should stay closed unless you lose a phase or have somebody screws up the phase order, shouldn't it?

I could see it being useful for protecting mechanical equipment from reverse rotation. But we've run air compressors for half of forever with just overloads

It still needs to be applied within it's voltage range.

POCOs here used radio control to drop out the 480 volt to pump panel control. Occasional intermittent power cycling would cause a fuse to blow. I incorporated the time delay to restart of the PLM into the POCO control. Saved more than one high dollar motor. Added CC fusing and control contact damage disappeared as well.

The newer ones monitor over & under voltage along with phase loss.

 

[hillbilly1]

Pulled it out, and it actually was rated for 480. Temporarily bypassed, compressor is running like a charm again. Must have been defective. Burned off all three phase inputs, so it failed in a spectacular fashion.

 

[retirede]

Pulled it out, and it actually was rated for 480. Temporarily bypassed, compressor is running like a charm again. Must have been defective. Burned off all three phase inputs, so it failed in a spectacular fashion.

Probably had a latent defect that got exposed when connected to 480V.

 

[hillbilly1]

New plm, everything back on line now. We will see if this one lasts.

 

[Joethemechanic]

It still needs to be applied within it's voltage range.

POCOs here used radio control to drop out the 480 volt to pump panel control. Occasional intermittent power cycling would cause a fuse to blow. I incorporated the time delay to restart of the PLM into the POCO control. Saved more than one high dollar motor. Added CC fusing and control contact damage disappeared as well.

The newer ones monitor over & under voltage along with phase loss.

I was thinking it might be another layer of protection for these line shaft pumps. Most of them have a rachet assembly on the motor that locks the rotor if it tries to reverse rotation. If they turn backwards they unscrew the couplers on the line shaft and there is no getting them back together without pulling the pump. And they can be hundreds of feet deep'

I had to pull one in Fair Lawn NJ one time. Somehow somebody unscrewed the coupler at about 100 feet, and then let it run with the shaft whipping around until it broke the pipe and dropped 200 + feet of pump down a 400 foot well. What a nightmare it was to fish that out. I think it took me a week

Nobody noticed until the lady that lived near the pump station called up and said "That little building of yours has been making a terrible noise for over a month

 

[don_resqcapt19]

Because overloads weren't good enough I guess

They often are not good enough to prevent motor damage if the motor is running when you lose a phase. This is especially true when the motor is operated at its service factor horsepower....a practice done by some air compressor manufacturers to permit them to use a small motor than they really should.

However some newer electronic overloads have phase loss built in. If they installed a separate phase loss relay, I can only assume that their overloads do not have that function.