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Discussion Starter · #1 ·
Hello All, I am new to this forum and this may be a dumb question but here goes:
If I am wiring a 208 volt 3 phase piece of kitchen equipment that pulls 33 amps and will run more than 3 hours (continuously) I multiplied by 125% which is 41 amps so I sized my breaker to a 45 amp 3 pole and will be using 3 #8 copper THHN wires with a #10 green ground. The appliance came with no cord so I was going to use 8/3 with ground 4 wire SO cord on the equipment with a male plug. Can I mark the white wire in the SO cord blue for my 3rd phase? Also can I use a 125/250 volt 4-wire range cord with male range plug on it and a flush mount 4-wire range receptacle using the silver neutral terminal as my 3rd blue leg? I don't do much 3 phase work and may be looking at this all wrong. Is there a different type of cord with 3 colors and a green, no white, that I should be using? Do they make a 3 phase 4 wire receptacle and male plug just for such a 3 phase application? Hoping someone can set me straight. Thanks for any advice.
 

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Hello All, I am new to this forum and this may be a dumb question but here goes:
If I am wiring a 208 volt 3 phase piece of kitchen equipment that pulls 33 amps and will run more than 3 hours (continuously)
I doubt it meets the Article 100 definition of a continuous load.


I multiplied by 125% which is 41 amps so I sized my breaker to a 45 amp 3 pole and will be using 3 #8 copper THHN wires with a #10 green ground.
Sounds OK, but a 40 would be fine for the 33 amp unit.

The appliance came with no cord so I was going to use 8/3 with ground 4 wire SO cord on the equipment with a male plug.
Is the appliance listed for cord connection or is it set up for raceway like LFMC?


Can I mark the white wire in the SO cord blue for my 3rd phase?
Yes



Also can I use a 125/250 volt 4-wire range cord with male range plug on it and a flush mount 4-wire range receptacle using the silver neutral terminal as my 3rd blue leg?
No.

Is there a different type of cord with 3 colors and a green, no white, that I should be using?
I am sure it can be ordered but I have never seen it used.

Do they make a 3 phase 4 wire receptacle and male plug just for such a 3 phase application?
You bet they do.

It looks like you need a NEMA 15-50R and 15-50P

http://www.stayonline.com/detail.aspx?ID=4752

By the way, you can order the plug 'straight' or 'angle' you will probably want the angle.
 

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Electric Al
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I doubt it meets the Article 100 definition of a continuous load.




Sounds OK, but a 40 would be fine for the 33 amp unit.



Is the appliance listed for cord connection or is it set up for raceway like LFMC?




Yes





No.



I am sure it can be ordered but I have never seen it used.



You bet they do.

It looks like you need a NEMA 15-50R and 15-50P

http://www.stayonline.com/detail.aspx?ID=4752

By the way, you can order the plug 'straight' or 'angle' you will probably want the angle.
Pin and sleeve connectors work well, or twist- lock male and female cord ends.
 

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Discussion Starter · #4 ·
Part of this equipment is a steamer and stays on in a preheated mode so it is ready at all times to use so I figured it would be considered continuous operation? 33amps x 125% is 41amps and my next largest size breaker is 45.

The piece of equipment came with a cord connector on the back of it from the factory and my customer wants it to be able to be disconnected easily so they can move it out and clean behind it occasionally.

Is there a code article that would allow me to mark the white wire in the SO cable with blue and use it as a hot?

And thanks for the link to the male plug and flush receptacle. This is exactly what I needed.
 

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Electric Al
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Part of this equipment is a steamer and stays on in a preheated mode so it is ready at all times to use so I figured it would be considered continuous operation? 33amps x 125% is 41amps and my next largest size breaker is 45.

The piece of equipment came with a cord connector on the back of it from the factory and my customer wants it to be able to be disconnected easily so they can move it out and clean behind it occasionally.

Is there a code article that would allow me to mark the white wire in the SO cable with blue and use it as a hot?

And thanks for the link to the male plug and flush receptacle. This is exactly what I needed.
Try; elecDirect.com for pin and sleeve, many fast food places use them.
 

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Part of this equipment is a steamer and stays on in a preheated mode so it is ready at all times to use so I figured it would be considered continuous operation? 33amps x 125% is 41amps and my next largest size breaker is 45.
It does not matter if part it stays on or the switches stay on the unit it self will cycle.

You can certainly call it a continuous load if you want but it is not needed.

Continuous Load. A load where the maximum current is
expected to continue for 3 hours or more.
It will not remain at the maximum current for 3 hours.


The piece of equipment came with a cord connector on the back of it from the factory and my customer wants it to be able to be disconnected easily so they can move it out and clean behind it occasionally.
The fact it came with a cord connector certainly suggests it is listed for use with cord as directly required by 400.

400.7 Uses Permitted.
(A) Uses. Flexible cords and cables shall be used only for
the following:

(8) Appliances where the fastening means and mechanical
connections are specifically designed to permit
ready removal for maintenance and repair, and the
appliance is intended or identified for flexible cord
connection

Is there a code article that would allow me to mark the white wire in the SO cable with blue and use it as a hot?
200.7(C)(3)

And thanks for the link to the male plug and flush receptacle. This is exactly what I needed.
No problem.

You can buy a 15-50P and 15-50R from any device manufacturer or decent supply house.
 

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The Accidental Welder
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I agree with the info already given, and that it's not a continuous load. Just wanted to caution you that if it was indeed a continuous load, the flexible cord would need to be a #6 as a #8 SO with 3 current carrying conductors is only good for 35 Amps (see Table 400.5(A)).
 

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Discussion Starter · #9 ·
If the nameplate load is 33 amps and it is a non continuous load should it be a 35 amp 3 pole breaker with #8 wire to my receptacle and a #8-3 w/ground SO cord? Or should it be a 40 amp 3 pole breaker, #8 to my receptacle, and #6-3 SO cord? Thanks for the help
 

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Town Drunk
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Bob Badger said:
It looks like you need a NEMA 15-50R and 15-50P

http://www.stayonline.com/detail.aspx?ID=4752

By the way, you can order the plug 'straight' or 'angle' you will probably want the angle.
I agree the angle is the way to go - the straight plug will cause the unit to sit too far from the wall.
 

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Just throwing this out there for the OP. If you go the angle plug route make sure the receptacle is installed so that when the cord is plugged in the cord is pointing down not up.
 
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