3-Phase plug / socket

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SteveM
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3-Phase plug / socket

Post by SteveM » Sun Apr 14, 2019 12:06 pm

I have a 3/4 hp 3-phase motor, and a static 3-phase converter.

I will eventually be building a rotary phase converter out of an old 1-1/2 hp 3-phase motor.

What is the "standard" 3-phase plug for this sort of application?

I understand that I could use anything I wanted and it wouldn't matter as long as it's all in my shop, but I'd like to have everything on whatever everyone else is (or is supposed to be) using.

Steve

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GlennW
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Re: 3-Phase plug / socket

Post by GlennW » Sun Apr 14, 2019 12:36 pm

I use L15-20P and L15-30P with the associated receptacles or cord caps.
Glenn

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Russ Hanscom
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Re: 3-Phase plug / socket

Post by Russ Hanscom » Sun Apr 14, 2019 1:21 pm

That is the correct call for 240V, 480 V takes L16 series.

There is usually in the NEC, national electric code, NFPA 70, tables that list all of the recommended plug/receptacle configurations.

Can also usually be found online by looking up a device manufacturer, Bryant, Hubble, … and checking their reference tables, or by visiting a local electrical supply store.

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SteveM
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Re: 3-Phase plug / socket

Post by SteveM » Sun Apr 14, 2019 7:18 pm

OK, thanks.

I need to test the motor and a friend is using L15-20 for his 3-phase outlet, so I'll be good with that.

Steve

Glenn Brooks
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Re: 3-Phase plug / socket

Post by Glenn Brooks » Thu May 02, 2019 11:01 pm

Steve, I always understood L15-20 denotes a 20 amp plug, on a 20 amp circuit. If this is correct, your circuit amperage will govern which style plug you will want to use. l15-30 for example, would be used in a 30 amp circuit. They have different receptical profiles to match the plug

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SteveM
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Re: 3-Phase plug / socket

Post by SteveM » Fri May 03, 2019 7:58 am

Glenn Brooks wrote:
Thu May 02, 2019 11:01 pm
Steve, I always understood L15-20 denotes a 20 amp plug, on a 20 amp circuit. If this is correct, your circuit amperage will govern which style plug you will want to use. l15-30 for example, would be used in a 30 amp circuit. They have different receptical profiles to match the plug
Yes, you are correct.

In my shop, this will be for individual machines with motors 1hp or less.

Engineers Toolbox says that a 3-phase 1hp motor at full load is only 3.6A
https://www.engineeringtoolbox.com/elct ... _1499.html
so the L15-20 will be more than enough.

If there is a smaller plug (rated for less current) then that would be fine as well.

I need to run 220 to the shop - right now, the only 220 outlet in the house is the dryer. I have a static converter, and I'll just rig that up with the proper plug and sockets, and eventually, I'll build a rotary converter out of the 3-phase motor I have.

Steve

Russ Hanscom
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Re: 3-Phase plug / socket

Post by Russ Hanscom » Fri May 03, 2019 8:17 am

For some period of time, my shop, welder included, shared a 220 V 40a amp circuit with a dryer. Never a problem as long as you remember who has priority and only run one thing at a time.

spro
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Re: 3-Phase plug / socket

Post by spro » Fri May 03, 2019 6:12 pm

A nice disconnect box with its own fuses is practically mandatory.

Glenn Brooks
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Re: 3-Phase plug / socket

Post by Glenn Brooks » Sat May 04, 2019 1:20 am

Should be more than enough... 220 amperage is normally half what you might see in a 110 v circuit. Although, some of the 220v 1 hp motors I researched online were rated at 12-15 amps! Not sure what their intended use was. Also unsure, actually don’t know how 3 Phase affects amperage. So Might be worth double checking your motor face plate as you plan out your electrical install. I ended up retro fitting my shop electrical circuits, (and sheet rock) 3 times before I finally got enuf circuits and outlets installed.

Glenn
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spro
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Re: 3-Phase plug / socket

Post by spro » Sat May 04, 2019 3:11 am

Disconnect boxes with a lever serve as a junction box. They are very important in isolating new work from older feeds. Troubleshooting requires narrowing any problem (unless you already know ) into sections. You don't want a latent issue coming to life when you're not there to see it.

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