Wire voltage rating?

I was just stealing some wire from a power adapter. The cable with two wires was rated at 300V, but the wires I've yanked out of there don't have anything printed on them. Does the additional insulation provided by the cable jacket make the difference here, or should I be safe using these wires at 110V?

That depends on where and how you want to use them.

They are probably OK for connections between components inside an appropriate enclosure, provided they are protected from abrasion and overheating.

They wouldn't be OK to run through a conduit or somewhere that they are exposed.

It's the neutral wire to my Love controller in my keezer. Will route between the pink foam board insulation and the wood.

I really can't advise you to use that wire in that application. It may or may not be suitable. Without markings there is no way to know.

You want something made for use as appliance wire.

Do you know the gauge of the wire? You need to be concerned with the current rating rather than the voltage rating.

It appears to be 18AWG, but current rating isn't really a concern, as this neutral wire is only powering the controller, not the freezer. I've got 14AWG 300V stuff powering the freezer. More than adequate. I just wanted to make sure the insulation it had on it wasn't going to break down at 110V since it didn't have the added cable jacket it came in. I'm going for it. I'm sure it's gonna be fine.

18awg is low voltage wiring..below 30 volts.

Its the type of wire used to connect your thermostat to your furnace. Not recommended for 110v. Unless otherwise printed on the insulation jacket.


14awg is rated for 15 amps..by code should only be subjected to 12 amps continuously.

Yellowirenut said:

18awg is low voltage wiring..below 30 volts.

Its the type of wire used to connect your thermostat to your furnace. Not recommended for 110v. Unless otherwise printed on the insulation jacket.


14awg is rated for 15 amps..by code should only be subjected to 12 amps continuously.

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The wire was in an overmolded cable rated for 300V. That's my overall question. What would you expect the wire inside this cable to be rated to? Also 300V? That's what I would expect, but I'm not sure. It's clearly not low-voltage wire.

And the NEC rates 14AWG for 25A with 90C insulation. Regardless, it's a chest freezer and is probably something like 5A.

The outer jacket on the cable is just for protection, not insulation purposes. I'd assume the wire is good for 300v but why risk it. Go buy yourself some 14awg wire. For the amount is sounds like you need it won't cost much.

There's a lot more to the NEC than that chart. In my 20yr electrical career 14awg is used for 15a circuits

Wire voltage rating has nothing to do with the conductor size or Gauge. The current draw in the circuit determines size.
Wire voltage rating is based on the insulation type and thickness. This is "generally" written on the insulation somewhere. If it is not, you have to assume it is rated for low voltage circuits.

kerklein2 said:

And the NEC rates 14AWG for 25A with 90C insulation. Regardless, it's a chest freezer and is probably something like 5A.

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This is true, but mandates a 15A overcurrent device.... The 25A can be used when applying the derating/etc rules. Still only available to supply 15A though.

What your describing is commonly called "lamp wire". Similar to: http://www.homedepot.com/p/t/202206...toreId=10051&N=5yc1v&R=202206453#.UUUHTVfwCF8


You probably shouldn't strip the jacket though, as its not intended to be... It will no longer meet code as it isn't marked (if thats a concern for you). Given the availability of proper wire, I wouldn't bother with it but its up to you.