Knob + tube extention

[ike5547]

Knob & Tube isn't in 300.15. So I don't think 300.15(F) applies.

It is mentioned in the first sentence, but I'm not sure if or how it applies to the rest of the section.

300.15 Boxes, Conduit Bodies, or Fittings ?Where Required.
A box shall be installed at each outlet and switch
point for concealed knob-and-tube wiring.

 

[shepelec]

300.15 does mention k+t for switches and outlets but not specifically for splices unless you count "other" cables.

I have seen fittings like this for romex in existing installs from the 50s or 60s but nothing new.

 

[al hildenbrand]

As far as the original post is concerned, I generally continue on with the knob and tube wiring method as necessary, installing my own tubes, knobs, loom, etc., until I reach the the next available box. I do not transition to romex in the middle of an existing run. I have vintage electrical manuals as a guide for proper technique and I've seen, studied and observed a great deal of existing K&T installations in San Francisco.

Sometimes the transition to romex with the fitting is helpful.

I once had three sets of K&T threeway travellers exposed in a floor that was opened for the purpose of adding a built up microlam beam. The travellers had to be cut for the microlam. The new beam was thicker than any tube I had access to, so I transitioned from K&T to NM and back to K&T. The inspector and I spent awhile with our Code books out, and then the install was approved.

 

[shepelec]

picture didnt load on last post.

 

[ike5547]

300.15 does mention k+t for switches and outlets but not specifically for splices unless you count "other" cables.

I have seen fittings like this for romex in existing installs from the 50s or 60s but nothing new.

For the application of 300.15 (A) through (M) it says the following:

"Where the wiring method is..." and inserts a list of wiring methods none of which are K&T.

So, I'm now thinking that a fitting for transitioning from K&T doesn't need to be accessible.

 

[Jim W in Tampa]

Sometimes the transition to romex with the fitting is helpful.

I once had three sets of K&T threeway travellers exposed in a floor that was opened for the purpose of adding a built up microlam beam. The travellers had to be cut for the microlam. The new beam was thicker than any tube I had access to, so I transitioned from K&T to NM and back to K&T. The inspector and I spent awhile with our Code books out, and then the install was approved.

I would rather seen them made in a box even if not accesable. The inspector most likely didn't care for it but had no better solution so passed it.

Why is it that K& T can have splices out of boxes but we cant do it with romex ?

 

[al hildenbrand]

It is mentioned in the first sentence, but I'm not sure if or how it applies to the rest of the section.

The first sentence is complete, by itself . . . boxes are required at switches and outlets.

300.15 Boxes, Conduit Bodies, or Fittings ?Where Required.
A box shall be installed at each outlet and switch
point for concealed knob-and-tube wiring.

The list I highlight with red underlined italics in the third paragraph in the opening of 300.15 has the reference to (A) thru (M). That is, (A) thru (M) apply to the list in the third paragraph, IMO.

 

[al hildenbrand]

So, I'm now thinking that a fitting for transitioning from K&T doesn't need to be accessible.

I agree with you.

 

[al hildenbrand]

Why is it that K& T can have splices out of boxes but we cant do it with romex ?

Quite simply, that was, and is, the wiring method for K&T.

It is the glaring exception to the "all splices must be in a box" meme.

 

[shepelec]

Is it possible that 300.16 means you need to use a fitting for the K+T to transition to the other methods and the splices would still need to be in a box? Like plastic bushings for a 4" sqr?

Since the article is specifically about K+T and 300.15 says "listed for the method".

I'm just throwing out ideas.

 

[al hildenbrand]

Is it possible that 300.16 means you need to use a fitting for the K+T to transition to the other methods and the splices would still need to be in a box? . . .

I think the answer to this idea is in the "or" :

(A) Box, Conduit Body, or Fitting. A box, conduit body, or terminal fitting . . .

I can use a box, or a conduit body, or a fitting.

 

[ike5547]

I saw a job today where the EC soldered romex onto k+t, taped the joint and left in the ceiling to be covered with drywall.

It sounds like the installation you saw didn't use a box or fitting of any kind so you were right not to approve the installation. Probably didn't use proper supports either.

 

[juptonstone]

knob and tube extension...

knob and tube extension...

I used to live up north... ran into a lot of knob and tube. We were allowed to repair existing, but never add to or modify it. Any changes - whatsoever - require a new electrical system. We did lots of total renovations because of that! No-one can sell a house with knob and tube anymore! And I don't know about the rest of country, but in Florida, if you're doing renavations on a house older than (?) 1974 - not sure of the exact year, it has to do with lead paint.. if you disturb more than 6 sq. feet of wall, you need a certified hazmat team to do the demolition or you get fined $5000 per day until you are in compliance! These days I run from knob and tube... last quote I gave was $14,000... The owner ended up listing the house "as is".

 

[Jim W in Tampa]

I used to live up north... ran into a lot of knob and tube. We were allowed to repair existing, but never add to or modify it. Any changes - whatsoever - require a new electrical system. We did lots of total renovations because of that! No-one can sell a house with knob and tube anymore! And I don't know about the rest of country, but in Florida, if you're doing renavations on a house older than (?) 1974 - not sure of the exact year, it has to do with lead paint.. if you disturb more than 6 sq. feet of wall, you need a certified hazmat team to do the demolition or you get fined $5000 per day until you are in compliance! These days I run from knob and tube... last quote I gave was $14,000... The owner ended up listing the house "as is".

Thats a new one on me. When did this law pass ? I am sure many simply get around this the easy way of stay under the 6 and then next month start all over again.
I rather enjoyed doing some rewires of homes in the 20's. Often I do little or no damage. Yes it is very costly. Rough estimate is one device per hour for me and a good helper plus material so depending on size of job could easily hit $14,000

 

[al hildenbrand]

Thats a new one on me. When did this law pass ?

I think he's referring to the EPA Repair, Renovation and Painting (RRP) program.

 

[LEO2854]

I think he's referring to the EPA Repair, Renovation and Painting (RRP) program.

For massachusetts Click this link
..http://www.mass.gov/Eoca/docs/rrp_notice.pdf

 

[dhalleron]

Would this circuit addition also require arc fault protection?

Would this circuit addition also require arc fault protection?

I actually pulled my first ever permit for a job I am doing this weekend. I’ve been in the trade a long time, but not as my own boss. It’s just a part time gig I am doing on the side but legally this time.

Anyway I was talking to the inspector about a circuit I wanted to extend. He said they are enforcing 2008 NEC and the circuit would need arc fault protection if I add any new wiring to an existing circuit. Would this new wiring in your example need arc fault protection too?

I don’t know for sure, but I have been told arc fault breakers and old wiring doesn’t always mix very well.

 

[Jim W in Tampa]

I actually pulled my first ever permit for a job I am doing this weekend. I?ve been in the trade a long time, but not as my own boss. It?s just a part time gig I am doing on the side but legally this time.

Anyway I was talking to the inspector about a circuit I wanted to extend. He said they are enforcing 2008 NEC and the circuit would need arc fault protection if I add any new wiring to an existing circuit. Would this new wiring in your example need arc fault protection too?

I don?t know for sure, but I have been told arc fault breakers and old wiring doesn?t always mix very well.

This is what i don't like seeing. If customer has and old house and willing to try to remove some problems they get stopped because of issues like arc faults that might just push the cost too far so they end up doing nothing.

 

[al hildenbrand]

Anyway I was talking to the inspector about a circuit I wanted to extend. He said they are enforcing 2008 NEC and the circuit would need arc fault protection if I add any new wiring to an existing circuit. Would this new wiring in your example need arc fault protection too?

This is a jurisdictional thing, at this point, from what I know.

I work in multiple jurisdictions with multiple AHJs and one allows the extension of an existing circuit without AFCI and another requires it.

This is what i don't like seeing. If customer has and old house and willing to try to remove some problems they get stopped because of issues like arc faults that might just push the cost too far so they end up doing nothing.

I think you make an excellent point. The AHJ in my area that covers the greatest amount of Minnesota decided along that line using Annex H 80.9 and CMP statements in the 2008 ROP to reverse their stance requiring AFCI for any new outlet to requiring AFCI for new circuits if the existing panel, with available space, is compatible with one of the forms of AFCI breaker manufactured today.

 

[acrwc10]

Thats a new one on me. When did this law pass ? I am sure many simply get around this the easy way of stay under the 6 and then next month start all over again.
I rather enjoyed doing some rewires of homes in the 20's. Often I do little or no damage. Yes it is very costly. Rough estimate is one device per hour for me and a good helper plus material so depending on size of job could easily hit $14,000

Jim your older then I thought if you were rewiring homes in the 20's.:grin: That must make you about 110 years old by now.

I am working on an old house (87years old) right now and it is K&T, what gets me is the K&T is in bad shape and convincing the owners to spend the few extra dollars to update the 3 untouched rooms is like pulling teeth. They are willing to spend an extra $2500 to move the service 100 feet away so they don't see it, but spend the same money to possibly prevent a fire "crazy talk". So all I can do is cut it back as far as possible then Megger whats left, NM to J-boxes and put them on arc fault breakers. Judging by what I have pulled out already, I'm guessing the Megger test is going to show some faults where they enter the outlet boxes.