Extension of circuit with no EQ ground

[Pizza]

I got a customer who wants another light opening in a room. However the only wiring method I would have to tap off of is Knob and Tube.
Can I tap off the old K&T?
I'm looking in 250.130 C in the 2011 code and don't see much about extending a circuit with no EQ ground.
Is there a better place in the code to look for my answer?:?
I thought I was sure that you could not extend a non grounded circuit

 

[Dennis Alwon]

You cannot extend a branch circuit that does not have an equipment ground. No compliantly anyway. Look ay 250.110

 

[brother]

I got a customer who wants another light opening in a room. However the only wiring method I would have to tap off of is Knob and Tube.
Can I tap off the old K&T?
I'm looking in 250.130 C in the 2011 code and don't see much about extending a circuit with no EQ ground.
Is there a better place in the code to look for my answer?:?
I thought I was sure that you could not extend a non grounded circuit

Well, like he said, I do not believe there is a 'compliant way' to 'extend' a circuit without a egc for a new light (even though I seen it done ALOT even with receptacles, but they at least put it on a gfci). I just know that if the outlet is 'existing' then you can put in a fixture without an egc as listed in NEC 2011 410.42 exceptions (ie gfci protection).

I was curious as to why the NEC would not allow the extension even with gfci protection, but they will allow a replacement with gfci protection in these old K&T houses. The end result is the same. Anyone care to explain??

 

[jaylectricity]

I was curious as to why the NEC would not allow the extension even with gfci protection, but they will allow a replacement with gfci protection in these old K&T houses. The end result is the same. Anyone care to explain??

Well in the first instance you are adding wiring that is not compliant.

In the second instance you are making an existing non-compliant installation a bit more compliant.

 

[SmithAndrewR]

Not worth the trouble

Not worth the trouble

Atricle 250.130 (c) does allow you to extend the circiut to the new light location but you would have to connect the EGC to one of the allowable points.

 

[gndrod]

Extended ckt

Extended ckt

I got a customer who wants another light opening in a room. However the only wiring method I would have to tap off of is Knob and Tube.
Can I tap off the old K&T?
I'm looking in 250.130 C in the 2011 code and don't see much about extending a circuit with no EQ ground.
Is there a better place in the code to look for my answer?:?
I thought I was sure that you could not extend a non grounded circuit

Not that I know of considering permitted changes, the best bet is to follow the local AHJ requirements that may have adopted (or not) a different rule to circuit extension. Possibilities for compliance to the latest NEC cycles are practically none when upgrading from a K&T extension.

At the best, installing an AFCI OCPD in a panel to protect K&T is limited to line-to-neutral appliance plug and cord arc safety providing there are no internal wiring connection anomalies in the old receptacle-switch circuit terminations and working parts. This can be most unlikely with old wiring devices but who knows until it is tried and accepted.

Extending the circuit with an AFCI receptacle without an EGC does not provide any ground fault protection from that BC but can still maintain a series or parallel ARC fault protection of that extension.

 

[Dennis Alwon]

Atricle 250.130 (c) does allow you to extend the circiut to the new light location but you would have to connect the EGC to one of the allowable points.

While I agree with you that would take almost as much work as getting a new circuit and you would then have to add AFCI to that circuit. I don't believe that is a good option.

 

[kwired]

Extending the circuit with an AFCI receptacle without an EGC does not provide any ground fault protection from that BC ...

Would you care to tell us why? No EGC means there will be no EGC as part of that circuit to fault to. Provide a ground from eleswhere and it will still trip if there is a fault to that ground. That is if an AFCI receptacle has same inherent GFCI as AFCI breakers have. I think there is at least one manufacturer that no longer has the GFCI component in their AFCI breakers (GE maybe).

 

[Pizza]

While I agree with you that would take almost as much work as getting a new circuit and you would then have to add AFCI to that circuit. I don't believe that is a good option.

Yes, and getting a new circuit up to the second floor would be very costly.

 

[Ponchik]

How about if you install AFCI breaker and install GFCI device at the location where you are going to extend it, without an EGC.