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Electrical Heater Double pole 20A breaker - AFCI or GFCI? No Neutral


Derstig's Avatar
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02-13-18, 06:43 PM   #1 (permalink)  
Electrical Heater Double pole 20A breaker - AFCI or GFCI? No Neutral

I have a 20A double pole breaker directly connecting to my electrical heater in our sunroom. There is no neutral wire. Questions:

- Does this breaker need AFCI and/or GFCI protection per NEC?
- If yes, can these breakers work without neutral wire by simply connecting the pigtail to bus bar?
- If yes, how can the breakerís protection feature work? I thought the point was to compare hot/neutral for a difference in amps?

Thanks

 
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02-13-18, 07:44 PM   #2 (permalink)  
240V circuits do not require GFCI or AFCI.

 
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02-14-18, 05:09 AM   #3 (permalink)  
Posted By: pattenp 240V circuits do not require GFCI or AFCI.
But surely there must be a reason why they make AFCI breakers? How can they work without neutral?

Also I dont see a gfci and afci dual function breaker thats 2 pole. The gfci ones are very old leading me to believe only afci is worth the money

 
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02-14-18, 06:36 AM   #4 (permalink)  
- If yes, how can the breaker’s protection feature work? I thought the point was to compare hot/neutral for a difference in amps?

In the general case, the GFI breaker looks at the difference of the TWO CURRENT CARRYING conductors. Doesn't matter if one or neither is grounded.

even more general; looks at the sum of ALL current carrying conductors and makes sure its zero. You can have a polyphase GFI breaker.

 
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02-14-18, 07:28 AM   #5 (permalink)  
Posted By: telecom guy - If yes, how can the breaker’s protection feature work? I thought the point was to compare hot/neutral for a difference in amps?

In the general case, the GFI breaker looks at the difference of the TWO CURRENT CARRYING conductors. Doesn't matter if one or neither is grounded.

even more general; looks at the sum of ALL current carrying conductors and makes sure its zero. You can have a polyphase GFI breaker.
Understood thanks. Why arent they required though? I thought afci was required everywhere.

 
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02-14-18, 09:04 AM   #6 (permalink)  
AFCI is only required for 15 and 20 amp 120 volt circuits.


All answers based on National Codes. Please check with your local building departments for local amendments.

 
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02-14-18, 09:36 AM   #7 (permalink)  
Posted By: pcboss AFCI is only required for 15 and 20 amp 120 volt circuits.
I understand its not required, but clearly for some reason there is a benefit for using one otherwise Siemens wouldnt make them In fact, for something that draws 20Amps over 240volts sometimes 4-5 hours at a time, I would say the insulation of that 12-2 romex is getting hammered compared to any other circuit in my house. Wouldnt you say its a good insurance to have?

 
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02-14-18, 11:21 AM   #8 (permalink)  
I can't think of a technical reason why 120 and not 240 get AFCIs. The AFCI actually started with the bedrooms, and has since expanded. But, yeah, 240 circuits are not immune to arcs. I would expect to see those come under code within the next couple revs.
Of course, the homes that benefit the most (old installs), have no legal incentive to upgrade.

I should also note here that AFCI's have had growing pains with falsing. Eaton, in particular had been highly sensitive to RFI. It's been a huge issue with radio operators and their neighbors.

 
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02-14-18, 01:35 PM   #9 (permalink)  
Posted By: telecom guy I can't think of a technical reason why 120 and not 240 get AFCIs. The AFCI actually started with the bedrooms, and has since expanded. But, yeah, 240 circuits are not immune to arcs. I would expect to see those come under code within the next couple revs.
Of course, the homes that benefit the most (old installs), have no legal incentive to upgrade.

I should also note here that AFCI's have had growing pains with falsing. Eaton, in particular had been highly sensitive to RFI. It's been a huge issue with radio operators and their neighbors.
Well, I like safety and I have no issues paying $88 Lets see how it goes

 
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02-14-18, 02:09 PM   #10 (permalink)  
AFCI is really there to protect arcing from cord or equipment that was plugged in the outlet. The reason why AFCI outlets can be used instead of breakers.
Having AFCI breakers will protect against arcing from the wires inside wall. However, this occurs rarely if the wiring is installed correctly to begin with.
Sames goes for GFCI. It is rare to get ground fault from wiring inside of the wall.

Since most 240V circuits are hardwired or just left plugged once it is plugged, there aren't much benefit from AFCI.
Also, all new portable AC (including window and through the wall. Both 120V and 240V) comes with ALCI instead, which works similar to GFCI.


If you want to install AFCI and GFCI on 240V circuit, you may. There is no need for neutral with 240V only circuit because current doesn't flow into neutral.
For 120V/240V circuit, such as range oven and dryer, you will need 2 pole breaker with neutral because current can flow into neutral as well. Regular 2 pole GFCI breaker will trip with these loads.

 
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02-14-18, 03:11 PM   #11 (permalink)  
Posted By: lambition AFCI is really there to protect arcing from cord or equipment that was plugged in the outlet. The reason why AFCI outlets can be used instead of breakers.
Having AFCI breakers will protect against arcing from the wires inside wall. However, this occurs rarely if the wiring is installed correctly to begin with.
Sames goes for GFCI. It is rare to get ground fault from wiring inside of the wall.

Since most 240V circuits are hardwired or just left plugged once it is plugged, there aren't much benefit from AFCI.
Also, all new portable AC (including window and through the wall. Both 120V and 240V) comes with ALCI instead, which works similar to GFCI.


If you want to install AFCI and GFCI on 240V circuit, you may. There is no need for neutral with 240V only circuit because current doesn't flow into neutral.
For 120V/240V circuit, such as range oven and dryer, you will need 2 pole breaker with neutral because current can flow into neutral as well. Regular 2 pole GFCI breaker will trip with these loads.
It looks like they dont make a dual function AFCI/GFCI 240volt breaker. Is that correct?

 
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02-14-18, 03:47 PM   #12 (permalink)  
It looks like they dont make a dual function AFCI/GFCI 240volt breaker. Is that correct?
I haven't seen one, and I did not fine any from a quick on-line search.
As far as I know GFCI is not required for any 240V circuit other than for spa or pool.

 
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02-14-18, 03:49 PM   #13 (permalink)  
Posted By: lambition I haven't seen one, and I did not fine any from a quick on-line search.
As far as I know GFCI is not required for any 240V circuit other than for spa or pool.
Got it thanks, I will go with AFCI only.

That being said, this baseboard is a few inches from the floor next to my desk. What if one day I accidentally poured water on it?

 
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02-14-18, 04:18 PM   #14 (permalink)  
It looks like they dont make a dual function AFCI/GFCI 240volt breaker. Is that correct?
That is correct. I just inquired about them and nobody makes a 2 pole AFCI/GFCI


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02-14-18, 04:24 PM   #15 (permalink)  
That being said, this baseboard is a few inches from the floor next to my desk. What if one day I accidentally poured water on it?
You will have to pour quiet a lot of water on exact spot to have a very distant possibility of electrocution.
Thermostat area is only place where water can come in contact with a uninsulated wire/connection. So, the water will have to enter thermostat or wire nut inside.
Even then, the current will flow through path of lowest resistance. That usually is grounded chassis or the other end of the pole.

 
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02-14-18, 05:04 PM   #16 (permalink)  
this baseboard is a few inches from the floor next to my desk. What if one day I accidentally poured water on it?
Fixed appliances are almost always a Class 1 device. Meaning the frame and all accessible conductive surfaces are grounded. So, even flooded, the case is still at ground potential. There may be some unwanted conduction going on inside, but the metal should all stay cold.

The big danger around water is the human skin becomes a lot more conductive when wet. Its the 9V battery on the tongue thing.

 
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02-14-18, 05:07 PM   #17 (permalink)  
The heater will get wet but will not become a hazard. It should be grounded.

 
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02-14-18, 06:20 PM   #18 (permalink)  
Got it, thanks guys. Much appreciated. I will just get the AFCI in there.

 
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