[quaker87]

Hey guys, i've used the "search" at the top and was able to get some information but I could use some more directed help with some directed questions I have:

I have approximately 40 ungrounded outlets being fed by knob and tube wiring. The inspector gave me the options of
1. go back to 2 prong outlets
2. go to all GFCI outlets
3. upgrade all my wiring

I'm leaning toward option #2 but have a few questions.

1. By going with 15 amp GFCI outlets for all my outlets with the "ungrounded" sticker, will they just trip if the load on them is too much?
I'm concerned about expensive electronics (led tv, ipad, etc) and in my extremely limited understanding of electrical it seems it would be safer using the GFCI (without a ground wire). Right now most of the electronics are on the same surge protector and doing okay.

2. would a 15amp gfci (ungrounded) being powered by knob and tube be strong enough for a smaller window a/c unit?

3. is there any reason to buy anything more powerful than 15amp gfci for common outlets? I ask because the hardward store has a great deal on them, $7.50 this week and i'm in the market for up to 40 of them...

 

[TarheelTerp]

I have approximately 40 ungrounded outlets being fed by knob and tube wiring. The inspector gave me the options of
1. go back to 2 prong outlets
2. go to all GFCI outlets
3. upgrade all my wiring

I'm leaning toward option #2 but have a few questions.

Do you still have the old 2 prong outlets that were taken out?

Restoring exactly what was there is the simplest and is adequate for almost all uses. For the 3 or 4 receptacles in the house where it will matter (or matter more)you could probably use more amps as well... add a few dedicated circuits for these as needed.

 

[quaker87]

unfortunately the old 2 prong outlets were thrown out years ago, so i'm really limited in my options and think the gfci outlets might be the way to go.

 

[joecaption]

All a GFI does is prevent you from getting shocked, the fuses protect the circut over loading.
Only need one GFI to protect any outlets that are down line from the first one. Trick is to figure out how the wires were run so you can find the first one in the circut.
Really pushing it trying to run an A/C or space heater on that old of wiring.

 

[Kyle_in_rure]

Also, keep in mind that many older outlet boxes are smaller-sized and may not accompany the larger GFCI outlets very well.

GFCI outlets do not necessarily trip in an overload, that is what fuses/breakers are used for. A GFCI outlet is designed to trip when there is uneven current on the conductors, which could lead to electric shock. They are safety devices. I personally feel (I may be wrong) that your electronics would not be much safer than they already are if they were on GFCI outlets.

And no, a window A/C does not usually need a special plug, unless the instructions say so. As long as it uses under 15 amps it will work fine on a regular outlet. The same goes for all of your household outlets.

I like TarheelTerp's idea of installing a couple of new dedicated circuits for your window A/Cs. Knob & tube may be okay, but once you add a load like that to a circuit with other appliances you can start blowing fuses and having other problems.

Older style two-wire receptacles are still sold at places like Lowe'/Home Depot, if you decide to go with that option.

 

[clydesdale]

GFCI outlets do not necessarily trip in an overload, that is what fuses/breakers are used for. A GFCI outlet is designed to trip when there is uneven current on the conductors, which could lead to electric shock. They are safety devices. I personally feel (I may be wrong) that your electronics would not be much safer than they already are if they were on GFCI outlets.

.

Most surge protectors I am aware of require a valid ground in order to protect your electronics. So you will be safer with the GFCI outlets but not your electronics.

 

[theatretch85]

I agree with the idea others have posted here to run dedicated circuits for the important things and high current draw (like a window A/C or a space heater). The knob and tube circuits could be protected with one GFCI (per circuit) at the main panel either with a standard GFCI outlet or a deadfront GFCI mounted right next to the panel. No need to change ALL the outlets on every circuit, and its a code compliant way to keep the grounded outlets on the ungrounded wiring.

 

[k_buz]

You will need tamper resistant GFI's as of the 2008 code cycle.

 

[NJMarine]

Some big box stores carry 2 prong recept. Also tamper resistant gfi may not be required if there is a rehab code being used in your area.
Replace with 2 prong outlets and if needed install new circuits where needed.

 

[AllanJ]

Going back to 2 prong receptacles will require undoing each outlet box, and having to unbend and rebend the wires in each box and may result in breaking of a wire. So I would favor installing "a bank of" "master" GFCI units (GFCI duplex receptacles okay), one for each circuit, in new boxes near the panel. There is the disadvantage of having to go down to the basement if a GFCI trips.

A GFCI unit provided more protection from electrocution than grounding of a circuit. Current code requires GFCI protection for many locations in the home but requires grounding of all wiring and receptacles.

A GFCI unit, with or without circuit grounding, does not by itself support surge protectors or provide surge protection. A surge protector will not perform its function without grounding.

 

[curiousB]

$7.50 this week and i'm in the market for up to 40 of them...

You don't need a GFCI for each location. Just one at the top of each circuit branch. That can't be more than 2-4 units. I like the suggestion of putting them all at the panel to feed the downstream wiring.