480 Volt plug on 208 Volt equipment

[Sharpie]

OK guys (and gals),

I've been asked to install a 208V, 20A, 3-PH receptacle for a chain hoist motor controller. The chain hoist controller says 208V on the name plate, but the plug on the controller is 480V 3-PH, 50A. (so is the recept for the chain hoist to plug into).

I plan to call the manufacturer to ask about this.

My question is: If the manufacturer of a piece of equipment tells you to use a plug that has the wrong rating on it, do you do it?

Thanks,

 

[pfalcon]

Short answer: NO! NO! NO!
Wiring the receptacle wrong for an application runs the risk of some other maintenance person pulling the plug and using it for his equipment. Wiring the plug wrong runs the risk of plugging to the wrong voltage with temporary wiring when the original plug is damaged.

Exactly what are we blowing up here?

Controller rating 208V, 20A with a 480V, 50A plug.
Old receptacle 480V, 50A?
What are we actually running on this circuit, is the cord set or the controller plate correct?

Replace old receptacle with new 208V, 20A receptacle?

Maybe he is asking to correct a violation by replacing the plug & receptacle with 208V, 20A?

 

[augie47]

It appears that 406.7 would identify this as a violation.

 

[Chenley]

I'd replace both the receptacle and plug also.

 

[wireguru]

what is the application and what kind of controller and motor(s) is it? Entertainment production types of chain hoist controllers use oddball connector configurations. Usually on these the power to the controller is via a 250v 3ph california special 50a twistlock, (or a 30a 3ph 250v 3p4w for smaller controllers) then the motors use a L16-20 for power to the motor -this is a 480v 3ph 20a 3pw4, and a L14-20 for the control (125/250v 20a 3p4w)


there is a code section -i dont remember what it is at the moment, which allows use of a non standard receptacle as long as its consistant across the facility, and the ratings of the receptacle are not less than what its supplied with. I have seen for example, hotels and convention halls using a 30a 3ph 347/600v 4p5w connector on a 120/208Y system to keep people from plugging in and using their power without paying the venue.

 

[iwire]

I am not sure any section prohibits using a high rated receptacle and plug.

I think 406.7 has to do with the construction of the parts, not the use of them.

I thinks it's bad design but not a violation.

 

[buzzbar]

I'm interested in this as well. It seems to me that as long as the receptacle rating is HIGHER than the device, it would be fine. As long as the OCD is correct. But I'm not sure.
406.7 doesn't apply here, I believe, because it refers to 'male' and 'female' devices being compatible.

 

[Pierre C Belarge]

I am not sure any section prohibits using a high rated receptacle and plug.

I think 406.7 has to do with the construction of the parts, not the use of them.

I thinks it's bad design but not a violation.

The section that Augie posted is interesting, when read for the way it is worded, and not for what we thought it may say. Whats that? Charlie's Rule


"...shall be constructed such that receptacle or cord connectors do not accept an attachment plug with a different voltage or current rating from that which it is intended."


The devices as per the OP are both of the same rating. The circuit supplying the equipment seems as per the OP to be correct.

It may not be a good design, but it seems to meet the mimimum code requirement.

 

[augie47]

I stand corrected,my reference did note construction (thanks, Bob)...so I'll take another shot,.,,since a motor is involved....how about 430.42(C) which states in part:
The rating of the attachment plug and receptacle shall determine the rating of the circuit to which the motor may be connected, as provided in Article 210.

(If there is only one voltage at the facility, I don't really see a problem, but the question is concerning if it's a violation)

 

[Cold Fusion]

I stand corrected,my reference did note construction (thanks, Bob)...so I'll take another shot,.,,since a motor is involved....how about 430.42(C) which states in part:
The rating of the attachment plug and receptacle shall determine the rating of the circuit to which the motor may be connected, as provided in Article 210. ...[/quote]
430.42 starts out with, "Motors on General Purpose Branch Circuits"
This does not appear to be a, "General Purpose Branch Circuits". 430.42 does not apply.

cf

 

[augie47]

correct (strike two for me today, I better quit posting).. apparently no Code violation.

 

[Cold Fusion]

...(strike two for me today, I better quit posting).. ...

Quit that
(either one - getting strikes, or quitting posting)

cf

 

[Sharpie]

There is both 480V and 208V available throughout the facility. They are now asking for my blessing on making an adapter cord that would take the 208 from a 208 Receptacle to a 480 connector on the cord.

I just don't like this whole thing (and really don't want to give my blessing).

But I'm not the AHJ.

 

[augie47]

I'm gunshy now , but, since you have both voltages on the premises, how about:
406.3(F) Noninterchangeable Types. Receptacles connected to circuits that have different voltages, frequencies, or types of current (ac or dc) on the same premises shall be of such design that the attachment plugs used on these circuits are not interchangeable.

 

[benaround]

Chris,

Have you asked them what they have against doing it right. They want your 'blessings'

because you better pray to God nothing ever happens.

 

[wireguru]

what is the application and what kind of controller and motor(s) is it? Entertainment production types of chain hoist controllers use oddball connector configurations. Usually on these the power to the controller is via a 250v 3ph california special 50a twistlock, (or a 30a 3ph 250v 3p4w for smaller controllers) then the motors use a L16-20 for power to the motor -this is a 480v 3ph 20a 3pw4, and a L14-20 for the control (125/250v 20a 3p4w)


there is a code section -i dont remember what it is at the moment, which allows use of a non standard receptacle as long as its consistant across the facility, and the ratings of the receptacle are not less than what its supplied with. I have seen for example, hotels and convention halls using a 30a 3ph 347/600v 4p5w connector on a 120/208Y system to keep people from plugging in and using their power without paying the venue.

im still curious what type of chain hoists and controller it is. 480v connectors are common between the chain hoists and controller on certain systems.

 

[Sharpie]

im still curious what type of chain hoists and controller it is. 480v connectors are common between the chain hoists and controller on certain systems.

It is theatrical. The motors have their own muti-pin specialty connectors. It is the power input that is the mismatched with the voltage and amperage.

I agree that in theater/production it can be it's own world, but I don't like being told by the manufacturer that it's the only plug/connector config. that they use and to just make it work.

I said no.

 

[M. D.]

It is theatrical. The motors have their own muti-pin specialty connectors. It is the power input that is the mismatched with the voltage and amperage.

I agree that in theater/production it can be it's own world, but I don't like being told by the manufacturer that it's the only plug/connector config. that they use and to just make it work.

I said no.

Good.......

 

[wireguru]

It is theatrical. The motors have their own muti-pin specialty connectors. It is the power input that is the mismatched with the voltage and amperage.

I agree that in theater/production it can be it's own world, but I don't like being told by the manufacturer that it's the only plug/connector config. that they use and to just make it work.

I said no.

ok that would be a 7 pin socapex connector. What brand motor controller? Motion Labs? Skjonberg? The standard for these motors is either the 7 pin socapex, or the combination of L16-20 for power and L14-20 for control. You may also run across CEE Form connectors on motors as well.

I agree it is odd the power to the controller is using a 480v connector -havent seen that before, just the 250v 3ph 3p4w 50a CS twistlock, or the 250v 3ph 30a 3p4w twistlock.

 

[zbang]

I agree it is odd the power to the controller is using a 480v connector -havent seen that before, just the 250v 3ph 3p4w 50a CS twistlock, or the 250v 3ph 30a 3p4w twistlock.

Definitely odd. Almost as if someone else put on the wrong connector earlier. I think the oddest connector I've seen on a (theatrical) motor controller was an L21-20 (or was it a -30?), and that's not that odd.