Wiring – Two Poles Three Black Wires and One White – Convert to 120 V Outlets

120-240vcircuit breakerwiring

I have a two pole breaker with three black wires and one white wire. The breaker is 50 amps. The three black wires are labeled "Load Power", and the white wire is labeled "Neutral".

Where an outlet used to be, there are three black wires and one green wire. This circuit used to power a hot tub.

Edit: Added photo of outlet box.

I no longer have the hot tub, and I would like to power regular 120 V (two or three prong outlets). Is it possible? How would I do the wiring?

If I cannot install regular 120 V outlets, what sort of outlet can I install? If it makes a difference, the outlet box is outdoors.

Best Answer

One of your three black wires is actually connected to the LOAD NEUTRAL terminal so you have two hots and one neutral. Unfortunately, whoever installed this used three black wires and apparently did not mark the neutral.

The wires can be used but you must replace the breaker. Putting a standard 15 or 20 amp outlet on a 50 amp breaker is highly dangerous and against code. You can use either a 240 volt (dual) 15 or 20 amp breaker with all three wires or cap off one of the hots and use a 120 volt (single) 15 or 20 amp breaker.

Two caveats: first, you need to identify the neutral wire and color the ends white, probably with white electrical tape. Second, the wire you have is too large diameter to connect to either the breaker or outlets. You’ll have to make pigtails using 12 AWG wire.

BTW, you currently have a GFCI breaker. You need GFCI protection on outdoor outlets. In my opinion, you’re better continuing to use a GFCI breaker since the outlet will be exposed to the weather and a GFCI outlet will have a short lifespan.

Understand the circuit

A standard duplex receptacle functions as both a receptacle, and as a junction. It allows you to connect cord-and-plug devices to the circuit, while at the same time allowing other hardwired devices to be connected to the circuit. Ground-fault circuit interrupter (GFCI) receptacles are similar, however, they offer ground-fault protection to all connected devices. To offer this protection, GFCI receptacles have two specific sides.

Line VS. Load

The Line side of a GFCI receptacle is where the feed line connects, to supply power to the device. The Load side of a GFCI receptacle is used to feed other devices, while offering them GFCI protection.

Find the line

Before you can figure out how to connect the device, you have to determine where the power is coming from, and where it's going to. To do this, you'll need a non-contact voltage detector, and a few twist-on wire connectors.

Turn off the circuit using the circuit breaker or fuse.
Verify the power is off using a non-contact voltage detector.
Remove all the wires from the receptacle, and place a twist-on wire connector on each wire individually.
Turn the power back on at the breaker/fuse.
Carefully, move the non-contact voltage detector near each wire.
When the meter lights up, mark the wire in some way.
Turn off the breaker/fuse again.

_{In this procedure, only one wire should make the meter light up. If more than one wire caused the meter to light, contact a local licensed Electrician.}

Now that you've located the ungrounded (hot) Line conductor, you'll have to also locate the Line grounded (neutral) conductor. To do this, simply follow the wire you marked in the previous step back to where it enters the box. You should notice that the wire is grouped with one to two other wires. The wire you found to be hot should be black, and it should be grouped with a white, and possibly uninsulated or green wire. These wires make up the Line feeder.

Hook it up

GFCI protection to downstream devices

Connect the black wire from the Line feeder to the brass screw terminal on the Line side of the GFCI receptacle (The receptacle should be clearly labeled LINE), the white wire from the Line feeder to the silver screw terminal on the Line side of the receptacle.
Next connect the black wire from the other group of wires to the brass screw terminal on the Load side of the GFCI receptacle, and the white wire to the silver screw terminal on the Load side of the GFCI receptacle.
Connect all the uninsulated/green wires together with an extra bit of uninsulated/green wire (about 6" long), using a twist-on wire connector or crimp connector.
Connect the other end of the extra bit of wire to the green (ground) screw terminal on the GFCI receptacle.

Once you restore the power to the circuit, all the devices downstream (on the Load side) from the GFCI receptacle will be GFCI protected. If this is not the desired outcome, please follow the steps below.

No GFCI protection to downstream device

Connect the black Line feeder to the other black wire and an extra bit of black wire (about 6" long), using a twist-on wire connector.
Connect the other end of the extra bit of wire to the brass screw terminal on the Line side of the GFCI receptacle.
Connect the white Line feeder to the other white wire and an extra bit of white wire (about 6" long), using a twist-on wire connector.
Connect the other end of the extra bit of wire to the silver screw terminal on the Line side of the GFCI receptacle.
Connect all the uninsulated/green wires together with an extra bit of uninsulated/green wire (about 6" long), using a twist-on wire connector or crimp connector.
Connect the other end of the extra bit of wire to the green (ground) screw terminal on the GFCI receptacle.
Leave the sticker covering the Load side terminals of the GFCI receptacle.

_{WARNING: If you lack the tools, knowledge, and/or confidence to complete this task, please do not hesitate to contact a local licensed Electrician.}

Electrical – Two white and two black wires in ceiling box

Alright there are two options.

1.Either your light was fed power from the panel (or a plug etc...) first.

The light switch box was fed power first and your light has two cables in it because it goes to another light after that one.

You need to first figure out where your strait hot power is coming in from. I understand that you believe you have found it. Just make sure to double check. Like you say use just a basic light switch (not that dimmer) and test for hot again. Is that wire you believed was hot , still hot when you have the switch in an up and down position? I will give you both options for wiring below. If there is power in both the up and down position of your light switch, than that is the hot power.

If the light was fed power first than here is how you connect the wires. Take your black (hot all the time wire) and marrett it onto the white of the opposite cable (that brings hot power down to your switch). On the same cable (the white you just used that goes to your switch) put the black wire onto the light (under the copper looking screw). Now you have one white wire left (it goes back to your panel somehow or another) so attach that to your silver coloured screw on your light. Done. You have a path, the hot going thru your switch, coming back to the light as switched power, going through your bulb and back to your panel.
If your hot wire feeds your light switch first. Heres how you wire it. Your switch box will be opened from testing and finding constant hot power in it so lets start there. Take your always hot black and put it on your light switch, than take the other black in that box and put it on the light switch. Take your white that is in the same cable as your always hot black and wire nut it with your other white. Now go up to your light box. Take the two blacks and wire nut them together with a pigtail. The pigtail will go to the copper coloured screw on your light. And take the whites and wire nut them together with a pigtail that you put on the silver looking screw on your light. Done. Power goes thru your switch, out of the switch to the light, thru the light and back on the white/neutral to the panel.

If you are using a light that you do not attach to screws you attach to wires, than the copper coloured screw is the equivalent of a black wire. And the silver coloured screw is the equivalent of a white wire. Your dimmer might be ruined but just try first with your basic switch and than add the dimmer in after to see if its ruined...

Have fun!