basic electrical questions

Old 09-15-14, 09:38 AM
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basic electrical questions

haven't wired in over 20 years. I have 6 questions that need answers.

1)can a ceiling fan light combo be wired to a touch control dimmer switch? I already wired it to switch and it works. I just want to know if it's safe. When I touch the dimmer switch it dims light as will as controls fan speed.

2)Have 100A panel with 12 gage wire for lighting and outlet circuits. Family member had 15A breakers and 20A outlets she wanted wired. Is it necessary to put 20A breakers in due to 20A outlets and 12 gage wire or is 15A breaker sufficient and safe?

3)is it a common practice to put 2-12 gage wires together behind each other on an outlet. I was taught to pigtail! There not jab in's, they're actually hooked behind and wrapped around the screw!

4)There's a 15A breaker that kicks on/off AC fan motor with 12 gage wire. Should I switch it to 20 A breaker due to 12 gage wire or leave it at 15A. I checked disconnect and it's 2-30A fuses that go to AC unit.

5)existing wiring had double duplex box with 12 gage wire going to a garbage disposal switch on one side and 15A receptacle on other side. Family member will be putting in new disposal later so now there is none. She wants a 20A GFCI added to replace original outlet. How do I determine which connection is line and which is load? The original receptacle had wired black to outlet and they striped wire in middle and wrapped around switch screw in stead of pig tailing? I haven't got GFCI outlet to work yet, any suggestions?

6) What's the formula or way to determine panel load calculation? So I don't over load the 100A panel?

Last edited by ray2047; 09-15-14 at 11:08 AM. Reason: Formatting for readability.
Old 09-15-14, 01:50 PM
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Welcome to the forums! I'll attempt to answer as best I can.
1) Your ceiling fan may create too much induction for the touch control to function properly, and the switch may not be fan rated, so you'll need to check on that part.
2) It is not absolutely necessary to increase the breaker size. 12 gauge wire will handle up to 20 amp circuits. You can leave the 15 amp breaker, but be aware it will give false signals to others who may work on the circuit.
3) Not clear on the question. If you mean two wires under one Pigtailing is a good method of wiring receptacles, although receptacles have two sets of screws and can handle two cables' worth of wires at once.
4) What is the rating of the A/C fan motor? That will determine the ampacity of the breaker needed, and you can not exceed 20 amps.
5) Kitchens must have two separate 20 amp circuits, both protected via GFCI, for small appliances, or countertop use. Where is the receptacle in question? Under the sink? On GFCI receptacles, there usually clear markings on the back indicating LINE and LOAD terminals. By connecting directly to the hot (LINE) wire, the disposal was not GFCI protected, but if it was a GFCI for small appliances, it was incorrect.
6) Googling "load calculation" will bring up a bunch of sites. One I pulled up was this Residential Load Calculation Spreadsheet ~ Electrical Knowhow. It seems to have a formula worksheet that you can use.

Hang in there, as others will chime in with much more information.
Old 09-15-14, 07:52 PM
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6) What's the formula or way to determine panel load calculation? So I don't over load the 100A panel?
You're mostly concerned with large loads.
1) electric hot water
2) electric heating
3) electric cooking
4) Central air

If you use gas or propane for most of your appliances then 100A is fine.

I have natural gas that I use for heating, cooking and hot water. I have central air and a built in swimming pool. So my big loads are the central air and the pool pump. My 100A service is adequate for my loads.

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