Home>Discussions>ELECTRICAL & LIGHTING>Modern outlets and ligh switches on K&T?
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chaz7979
Modern outlets and ligh switches on K&T?

I would say that 90% of my house has updated romex wiring but there are still a couple of light switches and outlets using K&T. I just repainted the inside of the house and updated all the outlets and switches but I have left the old K&T switches/outlets alone because they just dont look the same... those 70 switches are gnarly looking. Anyway, my question is... can I put modern light switches and outlets on those old K&T wires? Do I need to do anything special to do that? Do I need special switches or plugs? Thanks in advance guys... I read all the K&T threads and I couldnt find one where this question was asked.

By the way... the casing around the K&T is in great shape... at least the wiring I can see :)

Re: Modern outlets and ligh switches on K&T?
chaz7979 wrote:

I would say that 90% of my house has updated romex wiring but there are still a couple of light switches and outlets using K&T. I just repainted the inside of the house and updated all the outlets and switches but I have left the old K&T switches/outlets alone because they just dont look the same... those 70 switches are gnarly looking. Anyway, my question is... can I put modern light switches and outlets on those old K&T wires? Do I need to do anything special to do that? Do I need special switches or plugs? Thanks in advance guys... I read all the K&T threads and I couldnt find one where this question was asked.

By the way... the casing around the K&T is in great shape... at least the wiring I can see :)

Becareful the more you disturb K&T the insulation becomes brittle and crumbles. So the more you move it around the worse it becomes.

Switches should be fine.
But outlets today have ground terminals and K&T doesn't use a grounding conductor. If you replace them I suggest a GFI and use the labels in the box that says no ground is present. For further protection replace that circuits breaker with a new AFCI circuit breaker. good luck

Fencepost
Re: Modern outlets and ligh switches on K&T?

As for the light switches, you should be able to use any light switch for a replacement.

It's good to hear that the insulation on the wires is in good shape. A lot of these installations aren't so lucky. If you do end up with some bad insulation, I recommend covering the wire with heat-shrink tubing if you can't replace the wire. Use a heat gun -- not a torch or lighter -- to set the tubing. You don't want to catch something on fire. It's a lot neater and works better than tape.

chaz7979
Re: Modern outlets and ligh switches on K&T?

So, I should be using those outlets that you see in kitchens and bathrooms anywhere in my house where K&T is running to the outlet?

Re: Modern outlets and ligh switches on K&T?
chaz7979 wrote:

So, I should be using those outlets that you see in kitchens and bathrooms anywhere in my house where K&T is running to the outlet?

correct the reason behind that is it will pick up a fault without a grounded outlet and trip the outlet.

kentvw
Re: Modern outlets and ligh switches on K&T?

Here's a great article regarding receptacle replacement on K&T.

http://ecmweb.com/mag/electric_replacing_wire_ungrounded/

b_r
Re: Modern outlets and ligh switches on K&T?
kentvw wrote:

Here's a great article regarding receptacle replacement on K&T.

http://ecmweb.com/mag/electric_replacing_wire_ungrounded/

There's a section in that article that talks about K&T and mentions nuisance tripping -- is this implying that if you have K&T that you should NOT use GFCI receptacles?

My house has lots of K&T and it's characterized, which I thought was typical, by the hots running off connecting outlets along one way and then the neutrals coming back along a totally different path. I think the article was alluding to this as being important.

What I have done in situations where I have replaced a K&T receptacle is to replace it with a new, 2-prong receptacle. As everybody will cite chapter & verse, Thou shalt not use a three prong receptacle. Like the OP, I'd be interested in knowing if putting a GFCI would be OK.

chaz7979
Re: Modern outlets and ligh switches on K&T?

1. They sell 2 prong receptacles?
2. Can I put K&T into a plastic new work box or does K&T have to go into a metal old work box?

chaz7979
Re: Modern outlets and ligh switches on K&T?

I noticed those 2 hole outlets at HD today... how do they even allow those things to be sold? I thought you had to have a ground??? :confused:

canuk
Re: Modern outlets and ligh switches on K&T?
Quote:

I thought you had to have a ground??? :confused:

The only way you can have grounded outlets is to run ground wiring to the 3 prong outlets from the breaker panel.

The 2 prong outlets are allowed to be used for homes without ungrounded wiring .... that system is grandfathered in if that type of wiring exists.

Fencepost
Re: Modern outlets and ligh switches on K&T?
chaz7979 wrote:

I noticed those 2 hole outlets at HD today... how do they even allow those things to be sold? I thought you had to have a ground??? :confused:

They are permitted "for replacement purposes only." They are not permitted in any installation where a circuit is being modified. If modification is necessary -- say, you add an outlet -- then the whole circuit must be brought up to code.

To have a single GFI protect an entire circuit (or any number of outlets downstream) you must ensure that you can hook up both the downstream hot and neutral wires to it, and that NO other circuits share the neutral. GFIs work by making sure the current flowing through the hot and neutral wires are equal. You can have nuisance tripping if you have weak insulation on your K&T that is "bleeding off" electricity. But this shouldn't be seen as a nuisance, it should be seen as a symptom of a big problem that needs to be addressed.

If you aren't sure that your neutral serves only one circuit, or if the hot and neutral run different paths, you can simply install a GFI at each location, connecting only the "line" side. This will then protect YOU from faulty equipment plugged directly into the GFI.

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