Arc-Fault intent

[nietzj]

210.12 clearly states all 120 v single phase 15-20 amp loads need to be Arc-fault protected in a dwelling. So I have a situation in a Dorm, (Dwelling) and there is a 120 volt fan coil within the room which I have connected to an Arc-Fault breaker. Breaker has tripped many times and I'm planning to install dead-front devices and replace the Arc-fault breaker with a regular breaker. Not a great solution but it's code compliant. Just wondering if the code writers considered this situation. The fan coil is in the ceiling with guarded access for maintenance.

 

[petersonra]

I don't think a typical dorm is a dwelling.

Dwelling Unit. A single unit, providing complete and independent
living facilities for one or more persons, including
permanent provisions for living, sleeping, cooking, and sanitation.

 

[david luchini]

210.12(B) covers arc-fault requirements for Dormitory Units

 

[kwired]

I don't think a typical dorm is a dwelling.

Some are. But depending on which year of code applies, 210.12(C) includes most portions of dormitory units anyway.

 

[kwired]

210.12 clearly states all 120 v single phase 15-20 amp loads need to be Arc-fault protected in a dwelling. So I have a situation in a Dorm, (Dwelling) and there is a 120 volt fan coil within the room which I have connected to an Arc-Fault breaker. Breaker has tripped many times and I'm planning to install dead-front devices and replace the Arc-fault breaker with a regular breaker. Not a great solution but it's code compliant. Just wondering if the code writers considered this situation. The fan coil is in the ceiling with guarded access for maintenance.

Code writers never considered any inconveniences as a result of nuisance tripping in any AFCI requirements when composing final wording - ever.

A question though is since this is likely a small shaded pole motor - there is a chance that there is inductive kickback causing the tripping and not an actual arc fault or ground fault. If so is likely happening when the motor shuts off. If so you likely can install a snubber (resistor and capacitor in series connected across the switch) that will absorb the transient and that might solve your problem.

 

[eagleelec]

210.12 does not state "loads". It states outlets or devices. We then look at the definitions and find that a device is defined as "A unit of an electrical system, other than a conductor, that carries or controls electrical energy as its principal function." Outlets " A point on the wiring system at which current is taken to supply utilization equipment." In my opinion, your fan coil does not fit either of these definitions and therefore no AFCI protection is required.

 

[kwired]

210.12 does not state "loads". It states outlets or devices. We then look at the definitions and find that a device is defined as "A unit of an electrical system, other than a conductor, that carries or controls electrical energy as its principal function." Outlets " A point on the wiring system at which current is taken to supply utilization equipment." In my opinion, your fan coil does not fit either of these definitions and therefore no AFCI protection is required.

read your definition of outlet carefully again. The fan coil is utilization equipment, there is an outlet somewhere between that utilization equipment and the wiring system. Sometimes exact location of that point is debatable but there is an outlet somewhere there. Very possibly some devices involved as well. Does the unit have a switch or other control item? Probably.

 

[al hildenbrand]

210.12 does not state "loads". It states outlets or devices. We then look at the definitions and find that a device is defined as "A unit of an electrical system, other than a conductor, that carries or controls electrical energy as its principal function." Outlets " A point on the wiring system at which current is taken to supply utilization equipment." In my opinion, your fan coil does not fit either of these definitions and therefore no AFCI protection is required.

Welcome to the Forum. Going to the definition of Outlet for your first post is going straight to the deep end . . .

I agree with what you wrote: "your fan coil does not fit" the definition of Device or Outlet. That is because, as Kwired says: "The fan coil is Utilization Equipment." (another Article 100 Definition.) And whether the Utilization Equipment is hard wired, at a Lighting Outlet (Art. 100) or at a Receptacle Outlet (Art. 100), there is an "Outlet" at the point of connection to the Premises Wiring (System) (Art. 100).

 

[eagleelec]

I can agree with you to a point. If the unit is plugged in, yes. If the wiring hits a splice box on the load side or line side of the disconnect then to the equipment, yes. If the branch circuit passed through a disconnect switch then directly into the equipment, then i disagree. IMO if we interpret as you do then every 120v circuit in a residence would need to be AFCI protected. The other ingredient here is the utilization equipment is not within one of the described or similar rooms. It is above the ceiling.

This is a curiosity question. Do you AFCI protect a 120v boiler, furnace well pump, etc. in a residence that are not within the described or similar rooms?

 

[al hildenbrand]

1

 

[eagleelec]

So, by your thinking, a Branch Circuit supplying only recessed lighting that has no wall switch(es), but, rather, is controlled by an internet application IoT (Internet of Things) that directly addresses recessed bulbs from occupant cell phones, would never need AFCI protection in the Dormitory Unit designated rooms because the lights are above the ceiling.

This is do not agree with. IMO The recessed lighting fixture is part of the envelope of the room and and the socket is accessible to the occupant, therefore AFCI is needed. Hypothetical scenario here, I have a ceiling that is translucent and the light fixtures are mounted above the translucent material and the material is not removable. There is no control for the lighting within the space. Would the light fixtures need to be AFCI protected.

 

[retirede]

This is do not agree with. IMO The recessed lighting fixture is part of the envelope of the room and and the socket is accessible to the occupant, therefore AFCI is needed. Hypothetical scenario here, I have a ceiling that is translucent and the light fixtures are mounted above the translucent material and the material is not removable. There is no control for the lighting within the space. Would the light fixtures need to be AFCI protected.

“Socket accessible to the occupant” is irrelevant. AFCI are deployed to (supposedly) prevent fires due to wiring issues, not people protection.

 

[al hildenbrand]

This is do not agree with. IMO The recessed lighting fixture is part of the envelope of the room and the socket is accessible to the occupant, therefore AFCI is needed.

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The Opening Post tells us the 120 Volt Fan Coil is accessible from within the Dormitory Room for maintenance. As it is providing tempered air to the Dormitory, I am sure that the "Fan Coil Unit" is, at the duct grill, "part of the envelope of the room."

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Hypothetical scenario here, I have a ceiling that is translucent and the light fixtures are mounted above the translucent material and the material is not removable. There is no control for the lighting within the space. Would the light fixtures need to be AFCI protected.

While a hypothetical, this is not like the FCU "in the Dormitory Unit." It is rather like a Luminaire outside a fixed glass window.

 

[acrwc10]

I would be worried that taking the AFCI out may subject the installer to liability should a fire occur in that area. fire may consume the actual cause of a fire, leaving the installer trying to explain why there was no AFCI installed.

 

[jap]

there is a chance that there is inductive kickback causing the tripping and not an actual arc fault or ground fault. If so is likely happening when the motor shuts off. If so you likely can install a snubber (resistor and capacitor in series connected across the switch) that will absorb the transient and that might solve your problem.

Come on Kwired.......You don't really expect folks to have to go to that extent to keep an arc fault from tripping now do you???


JAP>