Is there a neutral in knob and tube?

The name knob and tube derive from the physical components of the system. Common features of knob and tube wiring are that it features a hot wire and a neutral wire with no third ground wire.

Can knob and tube wiring be used with circuit breakers?

Regardless of the wiring method, the breaker should be matched to the wire size. If the breaker is too big the wire could catch fire and cause a trip. The tube and knob cannot be used in thermal insulation.

How do I know if my knob and tube wiring is active?

Normally, spotting knob-and-tube wiring in your home is simple. Just go down to your basement, and take a look at the joists. Should you happen to see white ceramic knobs nailed to it with electrical wires snaking through them, then that means there is knob-and-wiring present in your home.

Can I grab a neutral from another circuit?

No, you can’t steal a neutral wire from another circuit. Each neutral wire is the return for the corresponding hot. If you “steal” a neutral from another circuit you run the risk of overloading that neutral wire (overheat, fire risk). Another issue might arise if the circuit later becomes a GFCI.

How do you tell the neutral from Hot on knob and tube?

Quote from the video:
Quote from Youtube video: Against neutral. If I touch this wire to the hot this should read to 120. Let's give it a go. So from this wire down through the floor which gratefully was opened. So that's pretty easy.

Which wire is the hot wire in knob and tube wiring?


Older homes with”knob and tube” (K&T) wiring only have a black “hot” wire and white “neutral” wire, without any ground wire. “This older type of wiring does not provide a ground for modern appliances, which can lead to damage to the appliance or even worse — injury or death,” says Dawson.

Can you ground a knob and tube outlet?

You cannot and should not install grounded electrical outlets on circuits where no ground path is actually present (such as knob and tube wiring). To provide a grounded outlet where no ground is present is dangerous.

What can I do with old knob and tube wiring?

If you have knob-and-tube wiring, most contractors will require you to have an electrician verify that it is not active. If it is active, you will need to have it replaced in order to insulate your home safely. When homes are rewired, electricians will often leave the old deactivated wiring behind.

Will GFCI work with knob and tube wiring?

Installing a GFCI breaker on a circuit containing knob and tube wiring, probably won’t provide any benefit. GFCI devices are designed to prevent electrocution, not to protect the wiring.

What if I don’t have a neutral wire?

Option 1 – Run a Neutral Wire

If you want to use smart switches and don’t have a neutral wire in your switch box, you can hire an electrician to run a neutral wire between the light fixture and the switch. You can also have an electrician rewire the switch and light fixture, which is potentially more expensive.

Why is there no neutral wire in my light switch?

Switches don’t get neutrals, they only want 2 wires: hot and switched-hot. Unless you’re dealing with a smartswitch, those take neutrals but there is still a switched hot to account for. And red is a common switched-hot color, but it would never, ever, ever, ever be used for neutral. Ever.

Can I use ground as neutral?

A ground is not a neutral period. The last thing you want is the chassis of your washer as a current carrying conductor. If your house has a bonded neutral and ground then it should be at only at one connector and that is your circuit breaker panel and nowhere else.

Can you touch knob and tube wiring?

The best way to handle knob and tube wiring is to get it replaced and updated with new, safe electrical in your home. DO NOT attempt to DIY any knob and tube wiring fixes or installs. Knob and tube electrical systems are at their highest risk of failure and fires when people attempt to fix it themselves.

How do you know which wire is hot on old wiring?

The black wire is the “hot” wire, it carries the electricity from the breaker panel into the switch or light source. The white wire is the “neutral” wire, it takes any unused electricity and current and sends it back to the breaker panel.

How can you tell which wire is hot and which is neutral?

Quote from the video:
Quote from Youtube video: If you don't get a voltage reading the wire is neutral. If you get a reading the wire is hot you can also use color coding to identify.

Why are there 2 black wires on light switch?

Black means hot, white signifies neutral, and green indicates ground. However, if you need to rewire a light switch or a plug socket, you may occasionally come across two black wires. It’s essential that you determine which black wire is hot before proceeding.

Why would my neutral wire be hot?

If the neutral is disconnected anywhere between the light bulb and the panel, then the neutral from the light to the point of the break in the neutral will become hot (and the device will be unpowered, because no current will be flowing through it). Look for a disconnected neutral.

What happens if you mix up hot and neutral wires?

This happens when the hot and neutral wires get flipped around at an outlet, or upstream from an outlet. Reversed polarity creates a potential shock hazard, but it’s usually an easy repair. Any $5 electrical tester will alert you to this condition, assuming you have a properly grounded three-prong outlet.

What will happen if live and neutral are reversed?

If your outlet’s polarity is reversed, it means that the neutral wire is connected to where the hot wire is supposed to be. This may not sound like a terrible thing, but it is. There is always electricity flowing out of an outlet with reversed polarity, even if an appliance is supposed to be off. Why is it dangerous?

Why would a neutral wire have voltage?

The voltage you are seeing on the neutral wire is conducting through that other load from the hot. Your voltage tester is detecting voltage without drawing current so the resistance of the other load is not seen. Try disconnecting/turning off all other loads on that circuit.