I have my dads old compressor and lately it has been kicking off at the overload. I don’t know a lot about electrical diagnosis. If I reset it the compressor runs fine for a while it has a 5hp motor. Thanks for any help
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3 phase compressor trips overload
- Thread starter Eli D
- Start date
wyliesdiesels
Well-known member
in addition to the above, what voltage is the motor wired for? its a dual volt motor...
It trips intermittently, so far I haven’t noticed when other than when my tools quit working. Today it worked fine all day and didn’t trip. I will check voltages tomorrow.Is it tripping at re-start or while building pressure?
What's the actual voltage while running?
Put an ammeter on it.
What size overloads are in it?
If you remove the belt does it still trip? What is the current w/o belt?
220 vin addition to the above, what voltage is the motor wired for? its a dual volt motor...
Thanks for the help.
alfredeneuman
Well-known member
It clearly says 230/460 on the nameplate.It trips intermittently, so far I haven’t noticed when other than when my tools quit working. Today it worked fine all day and didn’t trip. I will check voltages tomorrow.
220 v
It's either a 208V(Wye) or a 240V(Delta) supply voltage. 230V is made for a 240 supply only.
If it were 208V it would be marked 200/230 (200V motors are made for a 208V system).
Do you have an ammeter/clamp-on?It trips intermittently, so far I haven’t noticed when other than when my tools quit working. Today it worked fine all day and didn’t trip. I will check voltages tomorrow.
Also after removing the belt, see how the motor spins. Any noise? gritty feel?
Do the temps climb around the output shaft after in runs for a while?
wyliesdiesels
Well-known member
lol i didnt want to be that guy but yeah, it would be 240v (230v) or 480v (460v)....
If it was 220V 3Ø the high leg would be 190V, but there is 220Y/127V......lol i didnt want to be that guy but yeah, it would be 240v (230v) or 480v (460v)....
alfredeneuman
Well-known member
But he's in Oregon, not Brazil, Aruba, or Suriname.but there is 220Y/127V.....
walta
Well-known member
Just to be clear are you saying the 50-amp breaker in the photo is tripping and the only load is the 14-amp motor?
Seems like if it was a motor problem the overload on the motor would trip long before a correctly sized breaker.
Is it possible someone install a replacement motor on this compressor without the required motor overload?
It also seems very likely that if enough power to trip a 50 amp breaker passed thru your motor the motor would have smoke pouring out of it and would never run again.
How sure are you that the screws holding the wires to the breaker are tight?
Walta
Seems like if it was a motor problem the overload on the motor would trip long before a correctly sized breaker.
Is it possible someone install a replacement motor on this compressor without the required motor overload?
It also seems very likely that if enough power to trip a 50 amp breaker passed thru your motor the motor would have smoke pouring out of it and would never run again.
How sure are you that the screws holding the wires to the breaker are tight?
Walta
There is no 50a cb. That is a definite purpose contactor above an o/l relay.Just to be clear are you saying the 50-amp breaker in the photo is tripping and the only load is the 14-amp motor?
Seems like if it was a motor problem the overload on the motor would trip long before a correctly sized breaker.
Is it possible someone install a replacement motor on this compressor without the required motor overload?
It also seems very likely that if enough power to trip a 50 amp breaker passed thru your motor the motor would have smoke pouring out of it and would never run again.
How sure are you that the screws holding the wires to the breaker are tight?
Walta
As best I can read the FLAs are 14.4A @ 230V.
The heaters are N42's. The N42's are supposedly rated for ~26.5 - 37.5a........way oversized.
You need to find out the overload relay part number. Then you'll know which table to use in this A-B heater chart.
https://rockwellautomation.custhelp.com/ci/okcsFattach/get/18673_4 Best I can guess you should have N35-N37's
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The use of 220V to refer to 240V is highly ignorant.But he's in Oregon, not Brazil, Aruba, or Suriname.
alfredeneuman
Well-known member
Especially when the nameplate says something completely different.