I installed a ceiling fan/light combo in my room. because of the location of the switches, the switch that controls the light is on one side of the room on circuit 1, and the switch that controls the fan is on the opposite side of the room on circuit 2. What is happening is that there is only 1 common (white) wire coming from the fan/light combo. My circuit breaker keeps tripping if the commons from circuit 1 and 2 are tied together on the one common from the fan/light. Is there a problem with my fan? Is there a problem with tying 2 commons together from 2 different circuits? Is it my fancy CB? (it's one of those new ones required in bedrooms can't remember the name right now). Thought about hooking up a normal CB tomorrow to see if that makes a difference. Any other suggestions?
the fan and light should be on the same.sounds like you wired the fan light itself wrong.
Sounds like the feeds are at the switches and the neutrals are carried through to the ceiling box.You have to determine which two are the switch legs(hot). When the switch is on check each pair of wires from the switches with a tester the hot ones are the feeds for the fan and light the remaining two are the neutrals. This is one possibility always check with a local electrician if your not sure. We have already established in the question that one switch operated the light and one operated the fan I cant see the use for a three way.
If you trip the breaker, test to see if there is power in what you think is circuit 2. If you do indeed have power still in circuit 2 then you are on two different circuits(duh, I know) But I agree this sounds more like a three way circuit where your previous light was controlled from two different switches. I think it is unlikely that your fan has a problem. I think it is more likely that if you have two circuits, one of them is feeding current back into the neutral bus. Edit: OKso you have a 3 way circuit. Now the question is did the electrician who wired the unit do the 3-way partially in 14/2 which he would then use a white as a hot? This is very common though very much frowned upon. Keep a close eye on this and if you find there is funny things happening then check the commons as they enter the box and see if any is hot when you turn on a switch. Code states that circuit neutrals have to be isolated to the neutral bar. No combining circuits.
The problem is you are sharing the neutral for two circuits. You cannot do this with arc fault breakers. Why you have power from two sources to control one ceiling fan is pretty strange. You can remove the arc faults and it will work although they are required by code and your wiring will still be incorrect. You have a parallel path on your neutral. My suggestion is to disconnect one of the wires going to the fan, delete it from the circuit, and run a new wire to the fan, from the same circuit.
