80% Rule

[Mike Furlan]

What do you do with a 1500 W, 120V (12.5A) electric heater with a 15A plug?

80% of 15A is 12A.

210.23(A)(1) The rating of any one cord-and-plug-connected utilization equipment not fastened in place shall not exceed 80 percent of the branch-circuit ampere rating.

This device will plug into a 15A outlet, but by code should not be allowed.

 

[iwire]

I would use the nameplate voltage of 125 volts.

1500/125=12 amps

 

[Dennis Alwon]

What do you do with a 1500 W, 120V (12.5A) electric heater with a 15A plug?

What can you do? If it is UL approved it isn't your problem because you have no control where someone will plug it in. 12.5 amps will probably work just fine.

The reality is most podco's, at least around here are closer to 125 volts so the load would be closer to 12 amps.

 

[Mike Furlan]

I would use the nameplate voltage of 125 volts.

1500/125=12 amps

That is what I was hoping.

However, nameplate voltage is 120V.

 

[iwire]

That is what I was hoping.

However, nameplate voltage is 120V.

Then I would forget about it and move on.:grin:

 

[crossman]

Oops, if it is a resistive heater, then raising the voltage also raises the amperage and the wattage. Better tell the AHJ that the voltage is only 115.

 

[Mike Furlan]

What can you do? If it is UL approved it isn't your problem because you have no control where someone will plug it in. 12.5 amps will probably work just fine.

The reality is most podco's, at least around here are closer to 125 volts so the load would be closer to 12 amps.

Ok, let me rephrase the question.

What would you say if somebody wanted you to approve the use of a 1500W, 120V device to be plugged into a 15A outlet?

Would you put your name on a document saying that this was OK?

 

[celtic]

What would you say if somebody wanted you to approve the use of a 1500W, 120V device to be plugged into a 15A outlet?

I'd say they were blow drying their hair :grin:

 

[cschmid]

my first question is..is it a 20 amp circuit just because it is 15amp outlet does not meen it is not number 12"s..change outlet approve and move on..15amp circuit say sorry I cant approve that and give explaination as to why..

 

[crossman]

I'm with Dennis with respect to the UL issue. If it is UL approved with a 15 amp cordcap, then it is beyond the electrician's responsibility.

 

[Mike Furlan]

my first question is..is it a 20 amp circuit just because it is 15amp outlet does not meen it is not number 12"s..change outlet approve and move on..15amp circuit say sorry I cant approve that and give explaination as to why..

I have to assume that a portable device will end of plugged into a 15A circuit, and will not be able to approve this equipment.

Thanks.

 

[Mike Furlan]

I'm with Dennis with respect to the UL issue. If it is UL approved with a 15 amp cordcap, then it is beyond the electrician's responsibility.

Yes, it would be beyond an electrician's responsibility.

But, and you had no way of knowing, this is a matter put before an electrical safety comittee.

 

[cschmid]

the portable heater you are talking about is designed to be on 15amp circuit and is UL approved for 15amp plug and circuit..my next question is it a ceramic heater for office help to have by desk? I would say okay but if it is a milk house heater with dual heating ranges and no tip over switch I would say no..but they must have tip over switch on them most new on\es do but old ones do not..

 

[suemarkp]

What do you do with a 1500 W, 120V (12.5A) electric heater with a 15A plug?

210.23(A)(1) The rating of any one cord-and-plug-connected utilization equipment not fastened in place shall not exceed 80 percent of the branch-circuit ampere rating.

Read the beginning of 210.23. The subrule (A) only applies if there are two or more outlets. An individual branch circuit can supply a full 15 amps. Seems kind of like a stupid rule, since you have no control of what will be plugged in in the future and homeowners don't read instructions that specify "plug this into a individual branch circuit".

 

[Mike Furlan]

the portable heater you are talking about is designed to be on 15amp circuit and is UL approved for 15amp plug and circuit..my next question is it a ceramic heater for office help to have by desk? I would say okay but if it is a milk house heater with dual heating ranges and no tip over switch I would say no..but they must have tip over switch on them most new on\es do but old ones do not..

It is a ceramic heater for office use.

And it could end up being a lot of them, hundreds.

 

[Mike Furlan]

Read the beginning of 210.23. The subrule (A) only applies if there are two or more outlets. An individual branch circuit can supply a full 15 amps. Seems kind of like a stupid rule, since you have no control of what will be plugged in in the future and homeowners don't read instructions that specify "plug this into a individual branch circuit".

Sorry, you couldn't have known from the information I gave, but this will not be used in a home.

It will be the first of many such heaters going into hundreds of offices.

The only control over what happens to them, is to not approve of their use in the first place.

 

[cschmid]

ahh now I see the concern..that could lead to tripping of breakers and unwanted down time..just say no..

 

[Mike Furlan]

ahh now I see the concern..that could lead to tripping of breakers and unwanted down time..just say no..

The main issue is that it seems to be a clear code violation.

But, why does UL give a listing to a device that will almost certainly be used in a way that violates the NEC?

Sure it could be plugged into a 20A circuit. Why not require a 20A plug on it to ensure that it was plugged into a 20A circuit?

 

[cschmid]

I look forward to someone that can answer that question..

 

[Dennis Alwon]

The main issue is that it seems to be a clear code violation.

I am not sure it is a violation if the nameplate is 125volts as Bob had suggested.

But, why does UL give a listing to a device that will almost certainly be used in a way that violates the NEC?

I often wondered why many light fixtures had a UL approval-- I will probably never know why.

I see no problem with it. We are splitting hairs with .5 amps and the voltages-- I don't see that as an issue but....
The reality is an office generally has 20 amp circuits, however to approve these heaters on that scale would be a mistake unless a separate cir (20amp) were run to each of the units.