question about 300ft long wiring run

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Hi, I have to install a very long wiring run to a compressor. Here's the criteria: 1. approx 300ft from my main panel to the compressor 2. 220V motor, 1 phase, operating at 11.2amps at 10psi/60Hz.
Questions: 1. is #10 AWG sufficient? If so, how can I be sure (where could I check in the NEC to confirm)? 2. do I need to do a voltage drop calculation? 3. Will my motor burn out because it's so far from the main panel? 4. what size breaker is required? 5. would you recommend anything else? (i.e. maybe lighting protection because it's so far from the main house??) All technical advice appreciated. Thanks Theodore
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On Mon, 20 Jul 2015 22:36:10 -0700 (PDT), snipped-for-privacy@yahoo.com wrote:

Buy a couple of transformers and do it at 480v.
Voltage drop will kill you if you just try to do it with more copper
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On Mon, 20 Jul 2015 22:36:10 -0700 (PDT), snipped-for-privacy@yahoo.com wrote:

Disregard my previous reply. I am sorry I misread your question I thought you were saying 3000 feet.
10ga at 300 feet will drop about 8v. If you start with a true 240v, you end up with 232 at FLA but the open question is whether you will have enough to deal with the locked rotor to start it. I have a 120v 1hp compressor and we couldn't get it to start reliably at 150' with a 10ga cord. You may end up with 8ga or larger to make this work. 8ga gets you 5v drop at 11a but we still need to know what LRA is to decide.
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I'm using #10 for 85 feet. That's works ok. Its even 120volt probably more current. Never measured. I don't know the hp rating of motor. It has a 3 hp equivalent rating. The compressor may have a breaker specified. That said, without calculation, your cutting it close.
Greg
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On 7/21/2015 12:36 AM, snipped-for-privacy@yahoo.com wrote:

Probably ought to consider what it is at 150 psi. http://www.electrician2.com/calculators/vd_calculator_initial.html
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Sorry, I should have mentioned: it's a compressor for a pond aerator, so I don't expect very high pressure/load at all. Looks like an 8V drop over 30 0ft using this calculator. Is that something to be concerned about? I wil l TRY to find the Locked Rotor Amperes by contacting the manufacturer, but not hopeful. Any other suggestions?
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On Tue, 21 Jul 2015 06:13:14 -0700 (PDT), snipped-for-privacy@yahoo.com wrote:

That is a big honking aerator. It sounds like 2HP or so. Are you sure you are not looking at the 120v FLA?
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snipped-for-privacy@yahoo.com wrote:

I may be way off base here, but have you looked into keeping the compressor close to the power source and running 300 feet of air line to the aerator?
This company says their aerators can be operated with 1,000 ft of air tubing.
http://tinyurl.com/pdc4wet
Jeff
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On Thu, 23 Jul 2015 15:19:36 -0400, Jeff Wisnia

You have problems with long air lines just like long electrical lines and the answer is the same, bigger pipe.
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Not practical in my case... i'm feeding 4 aerator heads from this one compr essor. That would be a lot of hose spidering off in many directions.
Besides, my calcs show the voltage drop to be very small; the running curre nt is 6amps meaning startup current is maybe 18amps (well within a 10awg br eaker's capacity), and (unless I'm missing something) no respondant has rai sed a serious technical concern.
-Theodore.
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On Tue, 21 Jul 2015 05:31:00 -0500, Home is where I hang my hat

The current draw will be less at the top of the pressure range than it is in the middle. I plotted the curve of my compressor and it is a bell curve. That may seem counter intuitive but the compressor is simply free spinning at the top of the pressure curve because it is not moving much air. An example is your vacuum cleaner. If you block the hose, the motor speeds up because the load drops.
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On 07/21/2015 12:36 AM, snipped-for-privacy@yahoo.com wrote:

Agree w/ gfretwell that seems like awful big load for an aerator; how about a link to the particular unit you're planning on?
Given the figures above, the motor-sizing table in my copy of Richter's Wiring Simplified shows a #6 for 350-400 ft run 240V 2 and 1-1/2 hp, respectively. That's based on a 1-1/2% drop calculation for motor vis a vis the nominal 2% considered "standard" for other non-motor loads.
If this really isn't hard-starting, #8 would be marginal at 230-280 ft max distance for the two motor ratings above.
W/O further details, looks like #6 to me although probably could get by w/ #8. #10 is definitely too small for that size motor load...
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On 07/21/2015 1:29 PM, dpb wrote: ...

at that distance.
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Manufacturer FINALLY got back to me this evening! It's 11.2 amps at 110V, so only 6 amps at 220V. That said, I used the above website to calculate the voltage drop at 8volts over 300LF. This is 3.5%, which I beleive is quite acceptable.
I think I'm good, yes?
(all technical opinions greatly appreciated, especially dissenting ones)
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On 07/21/2015 7:29 PM, snipped-for-privacy@yahoo.com wrote:

That makes a lot more sense on the motor size. Now the question is, is it a dual-voltage motor?

That's too much for a motor circuit if that's what you computed for the running voltage; you'll be way under that during starting.

The table again shows you can go 340-ft 240V for 1/2 hp w/ #10 but only 220-ft w/ #12 (which, w/o looking is what I'd guess the above voltage drop would be for).
I'm saying you need #10.
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This sounds like a 1HP motor so I would go after that in your table.,
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On 07/21/2015 9:02 PM, snipped-for-privacy@aol.com wrote:

Realistically, it's likely 3/4 hp; the table for it would be 240-ft for #10 so would also need #8 for 300 to be within the 1-1/2% drop range it uses.
Seeing the nameplate for OP's actual motor would certainly reduce the guesswork...
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On 07/22/2015 8:12 AM, dpb wrote:

As a last point (altho OP is likely long gone)...One can never go wrong going up a size and just a quick survey showed #8-2 UF is 1.80/ft whereas #10 is 1.60, 0.20/ft difference. That would translate into $60 for the run difference. Difference likely to be less than that in quantity but if have no use for the extra and don't want to go to the trouble of reselling the end, might choose to but the length needed...
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On Wednesday, July 22, 2015 at 10:34:15 AM UTC-4, dpb wrote:

This photo is the _same_ model that I have:
http://yabe.chudov.com/Gast-1423-103Q-G626X-Vacuum-Pump-GE-5KC48PN0202AX-AC-Motor-1-HP-13-A-18233/DSC_0031.JPG
It's a 1HP motor, but I can't understand much else from the sticker. Any additional advice or instruction appreciated. .
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On 07/22/2015 8:33 PM, snipped-for-privacy@yahoo.com wrote:

OK, thanks....if it's really 300-ft, I'd definitely run #8. Doesn't give LRA and I didn't try to find more detail spec's via the part no but can't go wrong by the larger size as noted above. If nothing else, it'll run a tad cooler and you won't need to worry about starting effort shortening life by being marginally under-voltage.
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