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[email protected] krw@notreal.com is offline
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Default Help: New plug rating/size for air compressor?

On Sun, 11 Jun 2017 09:30:45 -0400, Jack wrote:

On 6/11/2017 8:23 AM, wrote:
On Sun, 11 Jun 2017 07:08:10 -0400, Jack wrote:

On 6/10/2017 6:30 PM, Michael wrote:
I need to replace the three prong plug on my air compressor. Before I head to Ace, can anyone tell me what size/rating plug I need? Here is a picture of the compressor.

https://ibb.co/h4LrTF

Much appreciated!
It says 15 amp but also says 2 hp. Normally, 2 hp motor would require
12 gauge wire, 20 amp plug and receptacle.


15A * 120V = 1800W
1HP = 746W ~ 2HP 1500W
Seems do-able on a 14ga cord (easily) and 15A plug.


Seems like it but it is not. Start up amps is a lot higher, and I've
yet to see a recommendation for 2hp shop motor run on 14 ga wire, or 15
amp fuse. Even fractional hp motors like washers, dryers, refrigerators
and so on should be run on 12 gauge, 20 amp circuits.


No, it's perfectly within the code. It would be better on a 20A
circuit (most NEMA 15-5Rs are on 20A circuits) but there is no need
for the cord to be 12A. It's overkill (though I'd probably do it).

My show vac says 5.5HP and it has a 16ga. cord and NEMA 5-15 plug. I
bet that keeps you up at night. ;-)


Doesn't keep me up a bit. I would love to see that 5.5hp motor drive a
24" planer, or his air compressor for that matter. Actually, I think a
2hp motor would normally require 10 ga wire, not 12.


The compressor isn't likely to actually require 2HP for long periods,
either.

A 5.5 hp motor would seldom be 120, but 220 or 3 phase. A 5.5 hp motor
would draw a lot of amps at startup, and running under load would not
last long on 16ga wiring, if at all. Your shop vac HP rating is, as you
well know, using methods that are meaningless when comparing motors and
work output.

My shop runs on 12 ga wire, and the only big motor is a 3hp and that
runs on 12 ga, 240 volt circuit.


Yikes! You didn't run 8GA wire! You slacker!