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

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tld38

Member
Location
Cleveland
Hello to all! I have always appreciated the great advice from members on this site. So let me thank all in advance. Tenant has space heater rated at 1500 w.@120V. Existing ckt is 15 amps. I informed homeowner that this heater requires a dedicated ckt, being that their are no plugs on a 20 amp ckt. My calc showed that heater exceeded permissable load by 60 watts. 1800x80%=1440 max watts. I assume from my calc that this heater would be allowed on a 20 amp ckt. 2400x80% =1920w., or 16 amps. One note from Mike Holts Understanding the NEC 2008 edition(Volume 1) Articles 90-450, Authors comment: UL and other testing labs list portable equipment ( such as hair dryers) up to 100% of the ckt rating. NEC is an installation standard,not a product standard, so it can,t prohibit this practice. There really is no way to limit the load to 80% of the branch ckt rating if testing labs permit equipment to be listed for 100% of the ckt rating. Any feedback on this authors comment is appreciated. Thanks again.
 

infinity

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Staff member
Location
New Jersey
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Journeyman Electrician
Another way to look at it is the heater load is 1500/120=12.5 amps. Since it needs to be considered a continuous load the branch circuit needs to be calculated at 125% so, 12.5 * 125% = 15.625 amps. That would be your minimum circuit ampacity which exceeds 15 amps.
 

iwire

Moderator
Staff member
Location
Massachusetts
I would bet the heater has a 15 amp male cord cap.

That being the case it is kind of pointless to worry about it, the heaters owner will move it about as needed and plug it in wherever.

I have one in my bedroom that is 12.5 amps and I plug it in to the same 15 amp circuit that powers the TV and lamps.
 

Mgraw

Senior Member
Location
Opelousas, Louisiana
Occupation
Electrician
"their are no plugs on a 20 amp ckt"
This was my clue to it being cord and plug but since I was not sure I used the word "If" just in case.
 

tld38

Member
Location
Cleveland
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Thanks to all of you. Let me re-clarify some things. This is a cord and plug connected portable heater with a built in blower that is UL listed, including a 15 amp cord cap. It is relatively new. Nameplate rating is 1500 W@120V. That is only info on nameplate. I should have stated that there are no 20 amp ckts available for plugs. only 15 amp. I,m assuming that if there were a 20 amp ckt , then there would be no issue since (2400x80%=1920W or 16 amps, and plugging this appliance into any plug on a 20 amp ckt would make this code compliant. That is not the case. In addition, this house was built in 1940 / knob and tube wiring. In addition, tenant is using a ground adapter since there is no ground. And this heater has a ground pin on the cord cap. I simply stated to the homeowner that this appliance requires a dedicated ckt because of the fact that 210.23 (A) (1) requires it bases on this particular situation. I do have a couple questions regarding replies to this thread. More than anything else, I want to be sure that I am understanding the codes intent here. To Mgraw,s reply: This is a 15 amp cord cap. My understanding of 210.23 (A) (1) is that this heater would be a code violation to use in this case because of the 1500 W rating on nameplate, and due to the fact that there are no 20 amp ckts. available. To iwire: Isn't anything over 12 amps a violation on a 15 amp ckt (1800x80%=1440W. or 12 amps regarding this particular discussion? To Infinity: Where in the code does it state that this heater needs to be considered a continuous load? I understand the calculation. And am sure that this heater would be plugged in for 3 hours or more on occasion, and if I ran a ckt, it would be a 20 amp ckt. Just some info about this call. Property owner called me to check out the situation at property address. Tenant stated that the cord was really warm at plug location. I verified that it was and assessed the situation. I stated that this appliance required a dedicated ckt., in this situation. Tenant stated that the owner should be responsible for this. Just so everyone understands, I don't care who pays. My #1 priority is Life and property protection for all concerned. I have seen consistent problems with these portable heaters over the years. Particularly in rental properties. Simply because of the fact that many people are just unaware of the potential dangers involved. And I overshoot when it comes to safety. I always try to reduce the load on the original house wiring whenever I can, including adding grounds where possible. I just want to be sure that my statement to tenant is correct in this situation. Thanks again for everyones imput. I,m always learning here.
 

kwired

Electron manager
Location
NE Nebraska
Thanks to all of you. Let me re-clarify some things. This is a cord and plug connected portable heater with a built in blower that is UL listed, including a 15 amp cord cap. It is relatively new. Nameplate rating is 1500 W@120V. That is only info on nameplate. I should have stated that there are no 20 amp ckts available for plugs. only 15 amp. I,m assuming that if there were a 20 amp ckt , then there would be no issue since (2400x80%=1920W or 16 amps, and plugging this appliance into any plug on a 20 amp ckt would make this code compliant. That is not the case. In addition, this house was built in 1940 / knob and tube wiring. In addition, tenant is using a ground adapter since there is no ground. And this heater has a ground pin on the cord cap. I simply stated to the homeowner that this appliance requires a dedicated ckt because of the fact that 210.23 (A) (1) requires it bases on this particular situation. I do have a couple questions regarding replies to this thread. More than anything else, I want to be sure that I am understanding the codes intent here. To Mgraw,s reply: This is a 15 amp cord cap. My understanding of 210.23 (A) (1) is that this heater would be a code violation to use in this case because of the 1500 W rating on nameplate, and due to the fact that there are no 20 amp ckts. available. To iwire: Isn't anything over 12 amps a violation on a 15 amp ckt (1800x80%=1440W. or 12 amps regarding this particular discussion? To Infinity: Where in the code does it state that this heater needs to be considered a continuous load? I understand the calculation. And am sure that this heater would be plugged in for 3 hours or more on occasion, and if I ran a ckt, it would be a 20 amp ckt. Just some info about this call. Property owner called me to check out the situation at property address. Tenant stated that the cord was really warm at plug location. I verified that it was and assessed the situation. I stated that this appliance required a dedicated ckt., in this situation. Tenant stated that the owner should be responsible for this. Just so everyone understands, I don't care who pays. My #1 priority is Life and property protection for all concerned. I have seen consistent problems with these portable heaters over the years. Particularly in rental properties. Simply because of the fact that many people are just unaware of the potential dangers involved. And I overshoot when it comes to safety. I always try to reduce the load on the original house wiring whenever I can, including adding grounds where possible. I just want to be sure that my statement to tenant is correct in this situation. Thanks again for everyones imput. I,m always learning here.

Where is code section - how about 210.19(A)(1):

(1) General. Branch-circuit conductors shall have an ampacity not less than the maximum load to be served. Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the minimum branch-circuit conductor size, before the application of any adjustment or correction factors, shall have an allowable ampacity not less than the noncontinuous load plus 125 percent of the continuous load.

Next question is determining if it is a continuous load or not. Being plugged in for more than three hours is not the determination, it is if the load is there for three hours or more. This being a thermostatically controlled unit - it may or may not be deemed a continuous load.

The fact that it has a 15 amp cord end and is (probably) a listed unit most likely means it is not deemed to be a continuous load otherwise it would have had a 20 amp end on the cord.

You can change the circuit to 20 amps, but I bet you notice little or no change in the operating temperature of the unit's supply cord.

I don't like these high wattage portable heaters myself, but there isn't a lot you can do about them. I would make sure there is at least a specification grade receptacle - the cheap grade receptacles don't seem to last very long with this kind of load plugged into them. There are other appliances that draw similar current, but generally not for such extended periods of time. Window A/C sometimes are just as bad because they can draw relatively high current for extended time also.
 

tld38

Member
Location
Cleveland
Thanks kwire. Sorry, by being plugged in for three hours, I actually meant that the unit would be on for three hours. So I am I correct in stating to tenant that this particular heater requires a dedicated ckt, in this particular circumstance regarding this post? Or let,s put it another way. Tenant can get a space heater not exceeding 1440 W. For in this particular situation, the 15 amp ckt, which these plugs are on is not adequate for this particular heaters demand according to 210.23 (A) (1) I just want to know if I'm right or wrong in referencing this code section as to why installing this heater on this particular ckt would be a violation. Thanks
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Thanks kwire. Sorry, by being plugged in for three hours, I actually meant that the unit would be on for three hours. So I am I correct in stating to tenant that this particular heater requires a dedicated ckt, in this particular circumstance regarding this post? Or let,s put it another way. Tenant can get a space heater not exceeding 1440 W. For in this particular situation, the 15 amp ckt, which these plugs are on is not adequate for this particular heaters demand according to 210.23 (A) (1) I just want to know if I'm right or wrong in referencing this code section as to why installing this heater on this particular ckt would be a violation. Thanks


This is a portable heater? Then IMO the NEC stops at the receptacle.
 

kwired

Electron manager
Location
NE Nebraska
Thanks kwire. Sorry, by being plugged in for three hours, I actually meant that the unit would be on for three hours. So I am I correct in stating to tenant that this particular heater requires a dedicated ckt, in this particular circumstance regarding this post? Or let,s put it another way. Tenant can get a space heater not exceeding 1440 W. For in this particular situation, the 15 amp ckt, which these plugs are on is not adequate for this particular heaters demand according to 210.23 (A) (1) I just want to know if I'm right or wrong in referencing this code section as to why installing this heater on this particular ckt would be a violation. Thanks

Like I said, I don't like these space heaters and think they are a fire hazard even if installed on a 20 amp circuit.

That said, I also think that if they indeed require a 20 amp circuit then they should come with a 20 amp plug. So they either do not follow codes, listing, or other requirements, or they are not considered a continuous load is the reasoning for a 15 amp plug.
 

tld38

Member
Location
Cleveland
Thanks. I'm simply stating to tenant that because this heater(1500 Watt) exceeds the max 1440W allowable rating on a 15 amp ckt/80%=1440W, that is applicable according to 210.23 (A) (1) that tenant must get a heater 1440 W or lower to make this code compliant in this situation, or better yet install a 20 amp ckt which would now have an equipment ground,and issue solved. Thanks so much for everyone's valuable input. I,m grateful.
 
requires a dedicated ckt because of the fact that 210.23 (A) (1) requires it bases on this particular situation.

Let's change the terms- the NEC does not define what a dedicated circuit is, or if it does, I can't find it, but most people think of it as a branch circuit used for (dedicated to) a single piece of equipment. In the case of the heater, it doesn't need a dedicated circuit in that sense, only access to a separate garden variety 20a branch circuit. If it were a bedroom, I wouldn't hesitate to put a reading lamp (50w) and alarm clock on the same circuit as the heater.

Beware of GFCI/AFCI requirements.

Also, please break up your posts into smaller paragraphs; makes it easier to read.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Thanks. I'm simply stating to tenant that because this heater(1500 Watt) exceeds the max 1440W allowable rating on a 15 amp ckt/80%=1440W, that is applicable according to 210.23 (A) (1) that tenant must get a heater 1440 W or lower to make this code compliant in this situation

I'm still not convinced with the information provided that this is applicable. Is this cord and plug heater fastened in place? If not, is there more than one receptacle on this 15 amp circuit?
 

kwired

Electron manager
Location
NE Nebraska
I'm still not convinced with the information provided that this is applicable. Is this cord and plug heater fastened in place? If not, is there more than one receptacle on this 15 amp circuit?

Same here. This is portable equipment. If it overloads a particular circuit the user will eventually learn not to run too much equipment on said circuit. Move it to another room and they may have no issue at all. Maybe they are only using it for a short time. Not quite same as it is for equipment that is fastened in place.
 
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