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Answers to Electrical Questions About Installing a New Light Fixture, Installing a Sub Panel and Installing a Cooktop and Separate Wall Oven

August 16, 2009

Question mark Rita Rothfeld asks:
I want to install a ceiling fixture and when I removed the cap from the ceiling box, there were 4 wires in it. –a black, white, red and the ground wire. I’m not sure which wires to connect to the fixture. I know that i usually connect the white, black and ground wire get connected. The red wire is confusing me. Please help me, so I can hang the fixture properly.

You should be correct in assuming the black wire will be energized once the light switch is turned on. However, I recommend using some type of a voltage tester to determine which wire is energized once the light switch is turned on. Typically, when you find a black and red wire in a box it is prewired for a ceiling fan. This would allow you to switch the fan and light separately.


Rich asks:
I have a question about hooking up a sub panel breaker the main box has a 20 and a 30 amp switches I installed a sub panel to match but I am a little confused on how to make it work. Please Help.

When installing a sub-panel you need to connect 4 wires between your existing breaker box and new sub-panel. You need 2 – hot wires, 1 – neutral wire and 1 – ground wire. In your sub-panel the ground and neutral bars need to be separate and the neutral bar can’t be connected the the box. Connect the ground wire to the ground bar. Next connect the neutral wire to the neutral bar and finally connect the hot wires to the main lugs at the top of your sub-panel.

In your existing breaker box, connect the ground to the terminal where all of the existing ground wires are connected to. Now connect the neutral wire to the terminal where the other neutral wires are connected to. Depending upon how your electric system is wired, your ground and neutrals may be connected together in your existing breaker box. According to the National Electrical Code®, this is required at the first point of disconnect only. Finally, connect the 2 – hot wires to a double pole breaker.


Bob asks:
I am replacing an electric stove with a seperate rangetop and wall oven. Can I just split the exsting 220 line to feed both, or do I need to run a seperate 220 line to each?

You may use the existing 220V line to feed one and install a new 220V line to the other. Check the amperage requirements on each unit. Typically, these units require 30 amps. This means the you will need to change your existing circuit breaker to a smaller size.