What size wire for 5 HP motor?
- Thread starter dlundblad
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1 hp is about 750watts so 5hp is about 3750.
i assume 220v which means 17 amps. considering turn on surge current for most motorsi would run 10awg if that was feasable,
If you dont mind some sag 12awg is commonly used on 20amp circuits. 20amp breaker should be fine,
i assume 220v which means 17 amps. considering turn on surge current for most motorsi would run 10awg if that was feasable,
If you dont mind some sag 12awg is commonly used on 20amp circuits. 20amp breaker should be fine,
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What does the data plate on the motor say (FLA, full load amps)? 10 gauge is good for 30 amps, 12 gauge good for 20A-but bigger is always better.
Originally Posted by bullwinkle
What does the data plate on the motor say (FLA, full load amps)? 10 gauge is good for 30 amps, 12 gauge good for 20A-but bigger is always better.
THIS
What does the data plate on the motor say (FLA, full load amps)? 10 gauge is good for 30 amps, 12 gauge good for 20A-but bigger is always better.
THIS
Please remember this. (I'm talking single phase)
If you under size your circuit amp capability at starting your voltage will go low which only increases current. Your centrifugal start switch in your motor will see this elevated current and life will suffer.
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2019/09/full-84637-36471-image.jpg "[Linked Image]")
Here is the nameplate from my Quincy
If you under size your circuit amp capability at starting your voltage will go low which only increases current. Your centrifugal start switch in your motor will see this elevated current and life will suffer.
Here is the nameplate from my Quincy
If you are 30' from your load center (breaker box) to meet code you must use # 6 and a 50 amp breaker. My compressor is directly on the opposite side of the wall from my load center. I used #8 and a 40 amp breaker since the inspector was long gone. #10 is not big enough!
Originally Posted by P10crew
If you are 30' from your load center (breaker box) to meet code you must use # 6 and a 50 amp breaker. My compressor is directly on the opposite side of the wall from my load center. I used #8 and a 40 amp breaker since the inspector was long gone. #10 is not big enough!
Don't quote the code if you don't know the code. In your application you could have used #12 and a 60 amp breaker. That meets code. Your way meets code but is way overkill on wire.
I need to know the full load amps to tell you what size wire and breaker to use. Air compressors like to use goofy special duty motors that have odd amperage.
If you are 30' from your load center (breaker box) to meet code you must use # 6 and a 50 amp breaker. My compressor is directly on the opposite side of the wall from my load center. I used #8 and a 40 amp breaker since the inspector was long gone. #10 is not big enough!
Don't quote the code if you don't know the code. In your application you could have used #12 and a 60 amp breaker. That meets code. Your way meets code but is way overkill on wire.
I need to know the full load amps to tell you what size wire and breaker to use. Air compressors like to use goofy special duty motors that have odd amperage.
Originally Posted by P10crew
Hel wig I do know the code .
Like the back of my hand.
You are wrong. Read article 430. Common thing that trips up lots of electrician that don't deal with industrial.
Hel wig I do know the code .
Like the back of my hand.
You are wrong. Read article 430. Common thing that trips up lots of electrician that don't deal with industrial.
Last edited:
Originally Posted by bullwinkle
What does the data plate on the motor say (FLA, full load amps)? 10 gauge is good for 30 amps, 12 gauge good for 20A-but bigger is always better.
FLA makes sense. I was originally just looking for "amps."
It's 21.5 FLA's.
What does the data plate on the motor say (FLA, full load amps)? 10 gauge is good for 30 amps, 12 gauge good for 20A-but bigger is always better.
FLA makes sense. I was originally just looking for "amps."
It's 21.5 FLA's.
https://www.cableorganizer.com/images/cooper-bussmann/lps-rk-fuses/motor-circuit-sizing.pdf
Go down to single phase page 11?
I don't do internet pi$$ing match's
I'm out!
Go down to single phase page 11?
I don't do internet pi$$ing match's
I'm out!
Originally Posted by P10crew
https://www.cableorganizer.com/images/cooper-bussmann/lps-rk-fuses/motor-circuit-sizing.pdf
Go down to single phase page 11?
I don't do internet pi$$ing match's
I'm out!
That isn't the Nec and is misleading if you don't know what the notes mean. I don't want a [censored] match either but it is irritating when people think they know how to do what I do for a living and put incorrect information out there.
https://www.cableorganizer.com/images/cooper-bussmann/lps-rk-fuses/motor-circuit-sizing.pdf
Go down to single phase page 11?
I don't do internet pi$$ing match's
I'm out!
That isn't the Nec and is misleading if you don't know what the notes mean. I don't want a [censored] match either but it is irritating when people think they know how to do what I do for a living and put incorrect information out there.
Originally Posted by dlundblad
Originally Posted by bullwinkle
What does the data plate on the motor say (FLA, full load amps)? 10 gauge is good for 30 amps, 12 gauge good for 20A-but bigger is always better.
FLA makes sense. I was originally just looking for "amps."
It's 21.5 FLA's.
10 gauge will work, but due to the 30 foot run, I would probably use 8 gauge. And a 30 amp breaker with either one. Your amperage is similar to most of the single phase ice cream machines I install, and some of them have compressors that can pull 80 amps (for a brief instant) at start.
Originally Posted by bullwinkle
What does the data plate on the motor say (FLA, full load amps)? 10 gauge is good for 30 amps, 12 gauge good for 20A-but bigger is always better.
FLA makes sense. I was originally just looking for "amps."
It's 21.5 FLA's.
10 gauge will work, but due to the 30 foot run, I would probably use 8 gauge. And a 30 amp breaker with either one. Your amperage is similar to most of the single phase ice cream machines I install, and some of them have compressors that can pull 80 amps (for a brief instant) at start.
The issue is you don't know the starting amps required based on motor. I presume no soft start? You likely need a 60AMP circuit breaker for the start.
Originally Posted by P10crew
Please remember this. (I'm talking single phase)
If you under size your circuit amp capability at starting your voltage will go low which only increases current. Your centrifugal start switch in your motor will see this elevated current and life will suffer.
Here is the nameplate from my Quincy
Single phase 230 VAC 5 HP
FLA 28 amps # 10 AWG copper wire
60 amp Circuit Breaker
or
40 amp dual element time delay fuse
Please remember this. (I'm talking single phase)
If you under size your circuit amp capability at starting your voltage will go low which only increases current. Your centrifugal start switch in your motor will see this elevated current and life will suffer.
Here is the nameplate from my Quincy
Single phase 230 VAC 5 HP
FLA 28 amps # 10 AWG copper wire
60 amp Circuit Breaker
or
40 amp dual element time delay fuse
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