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Hazo
Participant

Join Date: Jul 2011
Posts: 4

1/3 HP Motor

07/28/2011 6:30 PM

I have two 1/3 HP motor's in parallel, 480V, 3 ph, I can not run both at some time with out getting an overload. When I run one seperately, I am drawing 6-7 A no load.

My power supply is coming in on a 1000' of #12, my thoughts are to much V drop but calcs show to be with in 10%.

Any Ideas?
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Tornado
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#1

Re: 1/3 HP Motor

07/29/2011 1:25 AM

That doesn't compute; a 1/3 hp motor on 480/3 should draw about 0.8A full load current. It also sounds as though the two motors are paralleled onto one overload device, which would not normally be correct.

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Hazo
Participant

Join Date: Jul 2011
Posts: 4
#3
In reply to #1

Re: 1/3 HP Motor

08/01/2011 8:30 AM

Yes, they are paralleled, but with two overload devices. The motors are rated for 6 amps, I believe they typically run w/ load around 2 A, but not for certain.
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Hazo
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Join Date: Jul 2011
Posts: 4
#5
In reply to #1

Re: 1/3 HP Motor

08/01/2011 9:23 AM

I appologize, with further research I find you are correct. My FLA is 0.85A. I was mis informed, this is a hand me down project and information is proving more than difficult to come by. The tech said when running one motor they read 6-7 A. and I am now wondering if they only isolated one motor and possibly that motor has a short?
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lyn
Guru

Join Date: Oct 2008
Posts: 42355
Good Answers: 1693
#2

Re: 1/3 HP Motor

07/29/2011 11:29 AM

How hot does that 1000' of # 12 wire get? Can you hold it in your hand?

I'm with Tornado on this one.
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Hazo
Participant

Join Date: Jul 2011
Posts: 4
#4
In reply to #2

Re: 1/3 HP Motor

08/01/2011 9:06 AM

Its not melting, Its warm. The motor's run around 2 amps under load.
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