Receptacle Ratings

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augie47

augie47

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Tennessee
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State Electrical Inspector (Retired)
I inspect a facility that has 60 amp receptacles installed throughout the plant.
The recently added some 30 amp equipment and wired receptacles for that equipment. They elected (for durability) to use the same 60 amp plugs & receptacles.
I thought it was a violation of 406.3(F) however it not "different type current".
Any know of a Code Article that prohibits this ?
 
I did not explain completly (I see that now)...
The 60 amp receptacles installed for the 30 amp equipmemnt are protected by a 30 amp OCP device.
 
If I have a AC condensing unit, with a MOCP of say 35A, I would use a 60A rated disconnect. I don't see how this would be any different as long as the MOCP is in the panel and its not a fused disconnect.
 
my concern is with the "interchangabaility" ( as noted in 406,3)...
As set-up, the 30 amp equipment can be pliugged into the 60 amp protected plug.
 
If they changed the OCP really don't see a problem, but I'm sure some one will claim otherwise. I'm sure someone will say :"What if someone goes and change the breaker back to 60A? What if someone changed the breaker to 60 even with #10 wire and a 30A device?

augie47 said:
I did not explain completly (I see that now)...
The 60 amp receptacles installed for the 30 amp equipmemnt are protected by a 30 amp OCP device.
Click to expand...
 
augie47 said:
I did not explain completely (I see that now)...
The 60 amp receptacles installed for the 30 amp equipment are protected by a 30 amp OCP device.
Click to expand...

augie47 said:
my concern is with the "interchangeability" ( as noted in 406,3)...
As set-up, the 30 amp equipment can be plugged into the 60 amp protected plug.
Click to expand...

OK, so which is it? Is the OCPD 30 amps or 60 amps? These two statements seem to contradict each other.
 
infinity said:
OK, so which is it? Is the OCPD 30 amps or 60 amps? These two statements seem to contradict each other.
Click to expand...

They have numerous 60 amp receptacles supplied by 60 amp OCP devices with #6 wire. They are using the same receptacle (60 amp rating) and supplying them with 30 amp OCP devices on #10 wire for the 30 amp chargers.
 
augie47 said:
They have numerous 60 amp receptacles supplied by 60 amp OCP devices with #6 wire. They are using the same receptacle (60 amp rating) and supplying them with 30 amp OCP devices on #10 wire for the 30 amp chargers.
Click to expand...

Thanks for the clarification. ;)

I see no problem with either of those scenarios.
 
ceb58 said:
What about 406.7
Click to expand...

406.7 only requires the receptacle to not interchange with another voltage or current type, but 406.3(A) is the requirment your looking for:


(A) Grounding Type.​
​
​
​
​
Receptacles installed on 15- and 20-
ampere branch circuits shall be of the grounding type.
Grounding-type receptacles shall be installed only on circuits
of the voltage class and current for which they are
rated, except as provided in Table 210.21(B)(2) and Table
210.21(B)(3).​

Exception: Nongrounding-type receptacles installed in accordance​
with 406.3(D).
Click to expand...
 
hurk27 said:
406.7 only requires the receptacle to not interchange with another voltage or current type, but 406.3(A) is the requirment your looking for:
Click to expand...

Lets back up a little

They have numerous 60 amp receptacles supplied by 60 amp OCP devices with #6 wire. They are using the same receptacle (60 amp rating) and supplying them with 30 amp OCP devices on #10 wire for the 30 amp chargers.
Click to expand...

He is asking about 30 and 60 amp receptacles on 30 and 60 amp circuits.

406.7 states " plugs with a different voltage or current rating" to me that would be what is being discussed.
 
ceb58 said:
Lets back up a little



He is asking about 30 and 60 amp receptacles on 30 and 60 amp circuits.

406.7 states " plugs with a different voltage or current rating" to me that would be what is being discussed.
Click to expand...

No he is talking about 60 amp receptacles being used on 30 amp circuits, and the fact that the same 60 amp receptacles are being used on 60 amp circuits in the same building.

If you read 406.7 it has nothing to say about the rating of the circuit, only the rating of the receptacle and that it can not be compatible with plugs of a different rating,

Little Bill said:
He said they were 30A and 60A circuits/receptacles. Isn't this for 15/20A circuits?
Click to expand...

There is two complete sentences in 406.3(A) note the period between the word "type" and word "Grounding"

If we look at 210.21(B)(1) there is 2 exceptions for having a lower rated receptacle on a higher rating circuit, while the OP is speaking of the direct opposite, I can't find anything in the NEC that disallows the 60 amp receptacle on a 30 amp circuit except 406.3(A) second sentence?
 
Last edited:
infinity said:
Thanks for the clarification. ;)

I see no problem with either of those scenarios.
Click to expand...
So you see no problem in that someone can unplug the

[30 amp rated device re-fitted with a 60 amp plug]

from the

[30 amp OCP circuit with a 60 amp receptacle]

then plug the

[30 amp rated device re-fitted with a 60 amp plug]

into a

[60 amp OCP circuit with a 60 amp receptacle]

that is right next to it?

I see that as a problem.
 
mivey said:
So you see no problem in that someone can unplug the

[30 amp rated device re-fitted with a 60 amp plug]

from the

[30 amp OCP circuit with a 60 amp receptacle]

then plug the

[30 amp rated device re-fitted with a 60 amp plug]

into a

[60 amp OCP circuit with a 60 amp receptacle]

that is right next to it?

I see that as a problem.
Click to expand...

I meant from a code perspective. It's not a great design but code compliant nevertheless. The NEC is fine with it and so I can accept it.
 
Thanks guys.
Hurk, I can "read into" 406.3(A) and 406.7 that this would not be allowable and I apprecaite the link and input. I wish it were clearer. To that end, I have contacted a friend who is on CMP18 to see what he says.
(Kinda like going to the horse's mouth);)

I'll let you know his opinion.
 
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