Plug and receptacle for motors

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conmgt

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2 Phase Philly
I am wiring a few woodworking machines. They have a variety of motor sizes and have power cords for ease of mobility. Each machine will have a dedicated breaker and single receptacle. I remember something in the code about a single receptacle's rating needing to match its breaker. For example...a 15A single receptacle is not permitted on a 20A circuit but a 15A duplex or a 20A single is. If I'm sizing my branch circuit conductors to 125% of the FLC and the breakers to 250%, what is the minimum size receptacle permitted? For example, one saw has a 10hp motor. The conductor will be rated for 30A and the breaker will be 60A. Does the receptacle need to be rated for 60A or 30A? I think 30A since the conductors are rated that. Any thoughts?
Also, on that saw there is a note from the manufacturer that says a 30A circuit is recommended but consult your electrician. It has a 10hp motor and a nameplate rating of 24A. Should I go with 24A x 250% = 60A or the 30A?
 
Re: Plug and receptacle for motors

Does the receptacle need to be rated for 60A or 30A? I think 30A since the conductors are rated that. Any thoughts?
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A single receptacle can be larger than the branch circuit it is connected to. Look at 210.21(B)(1):


210.21(B) Receptacles.
(1) Single Receptacle on an Individual Branch Circuit. A single receptacle installed on an individual branch circuit shall have an ampere rating not less than that of the branch circuit.
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Re: Plug and receptacle for motors

210.21 B 1 brings you to 430.81 C 1/3 hp. or less shall be permitted to have a attachment plug and receptacle as a means of control.
 
Re: Plug and receptacle for motors

Look at 430.108(f) you can have a plug on any HP with a HP rated plug and recptical. 1/3 or less in not requierd to have a HP rated plug or appliance or room AC.
 
Re: Plug and receptacle for motors

RUWired... The saw has a 10HP 208V 3ph motor. The nameplate says 24 amps.

So, match the wire with a 30A recept or the breaker with a 60A recept.
210. 21(B) only says "branch circuit".
 
Re: Plug and receptacle for motors

1.) 30 A receptacle
2.) Overcurrent sized per 430.52
3.) Overload sized per Part III of 430
 
Re: Plug and receptacle for motors

benaround... no starters. The machines have on/off switches and some come equipped with SJ cords w/o plug ends, just little crimp terminations. I'm thinking of calling recept manufacturers and talking to the techs.
 
Re: Plug and receptacle for motors

Dose the equipment come with a data plate? Is at a manufactured piece of equipment?
 
Re: Plug and receptacle for motors

Conmgt,bdarnell hit it right with his remarks.Cord and plug is ok as long as motor has thermal protection in the motor.
Rick
 
Re: Plug and receptacle for motors

430.108 (f) say to use a HP rated plug. 10 hp rated plug is 60amp at 240v How do you get around not haveing a cord and a recptical and branch circuit less than 60 amp
 
Re: Plug and receptacle for motors

Wyatt,Your right, looking at Dons hp rated receptacles chart, 60amp device is for 10hp 208 3phase motors.
Rick
 
Re: Plug and receptacle for motors

I think by picking the recptical option to hook up the machines. it forces you to match the recptical and branch circuit. I culd not find in 430 or 670 any thing that give any leway with 210.21(b)1.
 
Re: Plug and receptacle for motors

I culd not find in 430 or 670 any thing that give any leway with 210.21(b)1.
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What kind of leeway were you thinking of? 210.21(B)(1) permits the receptacle to be larger than the branch circuit.
 
Re: Plug and receptacle for motors

You are right it says not less than. I miss read so I guess a 60 amp recpt on a 30 branch circuit with a 60 ocpd is fine.
 
Re: Plug and receptacle for motors

conmgt,

The reason I asked about starters is concern for, loss of power and the ability of the motor to start without warning to the operator when the power is restored!

Wheather it is a major power outage or just a c.b. that needs to be reset,not too many people look to turn 'off' something that is not running.

I hope you consider this.

frank
 
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