Combo Switch and Outlet Wiring in Bathrooms
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How to Identify the Electrical Wiring for a Combo Switch and Outlet: The sets of wires from two of the cables are spliced to each other which typically indicates that one cable is the power coming in. © By: Dave Rongey |
Wiring a Combo Switch and Outlet
Electrical Question: I have a house built in 1963, but the bathroom has been remodeled sometime since then.
I would like to place two switches:
- One has two single-pole switches to control a vanity light and an exhaust fan.
- The other is a switch and outlet combo, with the switch controlling an overhead light and the outlet is independent of the switch.
When I removed the old covers here is what I discovered:
- Four sets of Black and White wires running into the box for the 2 switches.
- Obviously 2 run to the devices, one comes from the power source.
What does the fourth one do?
- How do I tell which is the power source.
- And how do I tell which set of wires controls which device?
The combo box has three sets of wires:
- How do I tell which set controls the light,
- And which set controls the outlet and which is the power source?
This electrical question came from: Eve, a Homeowner from Dallas, Texas.
Dave’s Reply:
Thanks for your electrical question Eve.
Eve, this is a very good question.
Bathroom Circuit Wiring for Combo Switch and Outlet
Task: Identifying the Electrical Wiring
You may notice that in the Switch Box with the Four Cables.
- The sets of wires from two of the cables are spliced to each other which typically indicates that one cable is the power coming in.
- One is the power going out to supply power to another location, possibly another light switch box.
The other Switch Box with the Combo Outlet
- May be wired separately from the power source for the light switch.
- Or it may be sharing the power source.
- This will be noticed by observing the wiring and connections.
If the power for the outlet is shared with the power for the light switch then you will see the black wires from these devices spliced together or you will notice that the metal tab that connects the two portions of the outlet and the switch together on the brass screw side of the combo outlet switch. However, the power source for the outlet and the switch may be from separate sources which would be noticeable by observing the wiring.
Please Note:
Wiring sources and connections as mentioned above are best identified by an experienced licensed electrical contractor who understands electrical wiring and how to use a voltage tester to positively identify the circuit wiring.
More about Bathroom Wiring
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Fully Explained Photos and Wiring Diagrams for Bathroom Electrical Wiring with Code Requirements for most new or remodel projects.
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