Horsepower Rated Receptacle Required?

[Mikeq1]

Hi,
I don't wire a lot of motors and haven't come across this situation before. I have a customer who wants a machine hooked up that has a 7 1/2 hp motor on it. They want to be able to move the machine at times and are wanting it installed with a cord and plug.
My question is, if I have a disconnect installed before the receptacle, do I need a horsepower rated plug and receptacle, or can I use a standard plug and receptacle? The only thing I've seen relating to this is 430.109 (F), which says that if the cord and plug is used as a disconnect, then it needs to be horsepower rated.
Thanks for the input.

 

[hbiss]

Don't think I have ever seen a horsepower rated receptacle. (I never looked though so I could be wrong.) I know there are horsepower rated switches.

In your case just use a receptacle suitable for the circuit.

-Hal

 

[petersonra]

https://hubbellcdn.com/specsheet/WIRING_HBL2310SW_spec.pdf

this one indicates it is rated for 1 HP.

 

[rbalex]

See Section 430.109(F) if you are using it as the disconnecting means.

 

[augie47]

How does one assure the cord and plug will not be used as a disconnecting means ?
Would singage advising to turn the switch off before unplugging suffice ?

 

[rbalex]

How does one assure the cord and plug will not be used as a disconnecting means ?
Would singage advising to turn the switch off before unplugging suffice ?

In light of Section 430.108, I would start by assuming that it is a disconnecting means; i.e., if you can disconnect it, it is​, even if it isn't the only means.

 

[augie47]

In light of Section 430.108, I would start by assuming that it is a disconnecting means; i.e., if you can disconnect it, it is​, even if it isn't the only means.

That would be my thoughts but I don't recall it being officially addressed.
"Cause Bob says so" is official enough for me.
With that in mind, here is a Hubbell HP chart.

https://ecatalog.hubbell-wiring.com/Press/pdfs/H5115.pdf

 

[hbiss]

(F) Cord-and-Plug-Connected Motors. For a cord and plug connected motor, a horsepower-rated attachment plug and receptacle, flanged surface inlet and cord connector, or attachment plug and cord connector having ratings no less than the motor ratings shall be permitted to serve as the disconnecting means.

This to me means that if you don't want to install a separate disconnect before the receptacle you can use a horsepower-rated plug/receptacle as the disconnect means instead.

Problem I see is that, if you look at that chart, there is nothing suitable for a 7-1/2 hp motor.

-Hal

 

[augie47]

(F) Cord-and-Plug-Connected Motors. For a cord and plug connected motor, a horsepower-rated attachment plug and receptacle, flanged surface inlet and cord connector, or attachment plug and cord connector having ratings no less than the motor ratings shall be permitted to serve as the disconnecting means.

This to me means that if you don't want to install a separate disconnect before the receptacle you can use a horsepower-rated plug/receptacle as the disconnect means instead.

Problem I see is that, if you look at that chart, there is nothing suitable for a 7-1/2 hp motor.

-Hal

There is a 10HP, is there not ?

 

[Joe Villani]

Hi,
I don't wire a lot of motors and haven't come across this situation before. I have a customer who wants a machine hooked up that has a 7 1/2 hp motor on it. They want to be able to move the machine at times and are wanting it installed with a cord and plug.
My question is, if I have a disconnect installed before the receptacle, do I need a horsepower rated plug and receptacle, or can I use a standard plug and receptacle? The only thing I've seen relating to this is 430.109 (F), which says that if the cord and plug is used as a disconnect, then it needs to be horsepower rated.
Thanks for the input.

Take a look at Meltric.

IMO this is your best solution

http://www.meltric.com

 

[rbalex]

That would be my thoughts but I don't recall it being officially addressed.
"Cause Bob says so" is official enough for me.
With that in mind, here is a Hubbell HP chart.

https://ecatalog.hubbell-wiring.com/Press/pdfs/H5115.pdf

I do appreciate the confidence but, "Cause Bob says so", is not now, never has been, and probably never will be a sufficient basis for accepting anything. At best it can be taken as authoritative depending on the subject matter. I hope I'm clear when I'm just offering an opinion.
​

Hal has a point of course; the combination of Sections 430.108 and 430.109(F) together do require a plug and receptacle to be rated for the hp actually used. The essence of 430.108 is all disconnecting means must meet Sections 430.109 and 430.110. If a cord and plug can disconnect a motor is must be rated for it and not every motor circuit has a suitable plug/receptacle combination available.

 

[ElectricMatt]

https://www.hubbell.com/hubbell/en/...evice-Accessories/HBLMITL/p/166138?PN=HBLMITL

This is what I often use in a situation like this. The MITL disconnect will not allow it to be unplugged without first turning off the disconnect. It is a little pricey probably around 350 for both receptacle and disconnect.


Sent from my iPhone using Tapatalk

 

[Jraef]

Up to about 1HP (varies by mfr), a standard receptacle/plug connection can be used so long as that device is marked/listed for that specific HP (or more) at your voltage. But I don’t think you will find that for 7-1/2HP. At that level, your choices are the type indicated abouve; the ones where the plug is mechanically interlocked with the motor rated disconnect switch so that you cannot pull it out under load, or those like the Meltric that have a set of contacts inside that are rated for disconnecting under load. Meltric used the be the only game in town for that option, but that’s no longer the case, Hubble has similar products now called their “Advantage” series.

 

[Mikeq1]

Great points all, thanks for the input. The Hubbell Switched Twist Lock that Electric Matt linked to is about the only thing I see available that would work in my situation.