Electric space heater requirements(210.23(A)(1)

[iwire]

That tld38 is correct in his assesment that it exceeds 80% is correct that it should be on a 20 amp circuit.

I agree and if I was hired or sent out to install a circuit for that unit I would run a 20.

On the other hand I would never even bring it up if not asked about it.

 

[Mgraw]

From the UL standard

"16.6 The current rating of the attachment plug shall not be less than 125 percent of the current rating of
the heater except that a 15-ampere attachment plug is acceptable for a heater rated at not more than
1500 watts at 120 volts, or 3000 watts at 240 volts, and a 20-ampere attachment plug is acceptable for a
heater rated at not more than 2000 watts at 120 volts or 4000 watts at 240 volts."

 

[tld38]

Thanks, you all are awesome. One thing i have learned for sure. That I still have so much to learn! And I will keep learning to the end as we all do. In part, due to the members contributions and experience available from this site. Thanks again!

 

[kwired]

Thanks kwired. So this portable heater would not meet the definition as defined in 210.23(A)(1)? And 210.21(B)(2) specifically states "shall not supply a total cord-and-plug- connected load in excess of the maximum specified in Table 210.21(B)(2)" Also, Article 90.5 clearly prohibits, or requires an action by the words "shall" or "shall not" An interesting note here: I will reference Mike Holts " Understanding the NEC, Volume 1, Articles 90-450. Please see pg.81 which shows a picture of my exact situation. Permissible loads for cord-and-plug-connected equipment not fastened in place section 210.23(A)(1). The only difference is that in my case, it is a portable electric heater instead of a drill press. If these code sections that I have cited don,t apply to my situation, then what do they apply to? I believe that as an electrician, I have an obligation to know what i,m talking about. I looked up this info, and told tenant that it would be an NEC violation to plug this heater in the 15 amp duplex receptacle in this area that is fed with 14 gauge wire, and on a 15 amp ckt which also has other receptacles and also some lights on the same ckt as well. If I,m wrong, please just help me understand why I am misinterpreting the code on this issue so that I can be a better informed electrician at the end of the day. Thanks again.

My point all along has been this is portable equipment, the original installer had no idea it would be used on the circuit and who is to blame for any code violations? I do not disagree with any of the code you have brought up. If I wire a new home and 6 months later the owner complains about tripping breakers because they have space heaters overloading circuits was it my fault I did not run a dedicated circuit to each heater location, especially if I did not know there would be such heaters in use?

I do realize your circuit is overloaded, and that proper overcurrent protection still protects the branch circuit wiring. When this becomes a problem for the owner, they call you and it is time for you to provide a solution. You have a few options, one of them being installing a new circuit to connect this heater to. This heater still has a plug that will plug into just about all the receptacles in the home though. Who is at fault if they forget to plug it into its dedicated outlet? This is not quite the same as a refrigerator or washer that pretty much has a dedicated place for the appliance.

Next homeowner may not use such a heater or may wish to use one at a different receptacle location. We can't cover all those what if's unless maybe we run a dedicated circuit to every outlet.

 

[tld38]

Good point kwired. Thank you. I understand. This is the only location in the house where this heater would be used because it is a sun porch area. I have advised owner that a 20 amp branch ckt should be installed at this location for serving this heater. What I like to do in these situations is determine the actual connected load to an existing ckt, then determine what appropriate action I may be able to take to decrease the load on the existing ckt. The original ckt. in place has no equipment ground, and whenever possible, I like to remedy that as well. Thanks again.

 

[suemarkp]

As far as the voltage rating on the appliance I would go to 110.4. The rating on the appliance is equal to or exceeds the branch circuit rating. I do not see how 125 volt rating on a appliance lowers the ampacity when used on a 120 volt rated branch circuit.

For a resistive load, its current draw will reduce as the applied voltage is reduced. Since they don't tell you the resistance of the heater, you'd have to work it backwards from the applied voltage and watts. Incandescent light bulbs are another area where you see this -- a 100W lamp with a 130V rating is dimmer than one with a 125V rating and both are dimmer than one with a 120V rating when each is used on a 120V circuit. But the 130V rated lamp will last the longest. None except the 120V lamp will draw 100W because the others were designed to be 100W at higher applied voltages.

Remember, this only works for resistive loads. Induction motors work backwards of this rule because they tend to do fixed work so their "resistance" varies.

As others have pointed out, the nameplate shows 120V and not 125V. It is some UL quirk that allows the 120V 1500W heater to use a 15A cord cap.

 

[david]

For a resistive load, its current draw will reduce as the applied voltage is reduced. Since they don't tell you the resistance of the heater, you'd have to work it backwards from the applied voltage and watts. Incandescent light bulbs are another area where you see this -- a 100W lamp with a 130V rating is dimmer than one with a 125V rating and both are dimmer than one with a 120V rating when each is used on a 120V circuit. But the 130V rated lamp will last the longest. None except the 120V lamp will draw 100W because the others were designed to be 100W at higher applied voltages.

Remember, this only works for resistive loads. Induction motors work backwards of this rule because they tend to do fixed work so their "resistance" varies.

The equipment voltage rating is different than saying 15 amps @ 120 volts. Equipment is required by 110.4 to have a rating equal to or greater than the branch circuit rating it is listed to be used on. Take receptacles that have a 125 volt rating designed to be used on a branch circuit rated at 120 volts.
If the appliance would have said 15 amps @ 125 volts than using the equipment on a 120 volt rated branch circuit result in a change in the circuits ampacity.
When looking at 125volt rated equipment make sure that the rating was intended to be used in the VA (wattage) calculations to determine the ampacity for an appliance.

I personally never seen a space heater with a 125 Volt rating. I looked at the one in the office bathroom here it has a 120 volt 60Hz 11 amps 1320 watts