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Bath fan tripping the breaker

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Kat2014

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Installed new bath exhaust fans yesterday. First one was fine. Second one (identical) not so much. I turned the power back on and the fan and lights came on as normal, but when trying to turn the fan off, the breaker pops.
(There was a fan there before; this is a replacement - it was wimpy, but caused no electrical problems) I seemed to hear a sound from the actual wall switch as well as the breaker popping - I thought it might be arcing - a very old switch, so I swapped it out. Same problem.

I disconnected the wiring harness on the fan for now, so I can still have lights in the bathroom till I figure this out. There was a fan already in this location, and I doubt this one has a much higher electrical draw - not so much higher as to pop a breaker. I plug some high draw things into this circuit (hair dryer, etc) and there is no problem. Maybe I am looking at a problem with the fan itself?
 

Snoonyb

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Seperate the fan/light away from that circuit, to a light circuit.
 

Jeff Handy

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I have also installed bath exhaust fans that nuisance trip on a gfci, if that is what you really mean.
I think it is just an issue with electrical noise or surges as the motor is winding down.

Either replace the fan motor and hope it stops, or remove the fan from a source of gfci switched current.
 

afjes_2016

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If the breaker trips the exact moment you flip the switch to the "off" position then you more than likely missed wired something. A breaker tripping immediately indicates a dead short. If a breaker takes some time to trip then it more than likely indicates an overload on the circuit.

Check you wiring again. Look at the diagram of the unit that came with it. You must have wired something incorrectly.
 

Jeff Handy

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Is this tripping a gfci breaker, or a gfci outlet, a gfci switch, or a regular circuit breaker?

Please confirm.
 

Kat2014

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It trips the gfci outlet and a regular circuit breaker.
 

afjes_2016

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It trips the gfci outlet and a regular circuit breaker.
Please clarify: You state it trips the GFCI receptacle along with the regular breaker. When you say it trips the GFCI receptacle does it actually trip it or does the GFCI receptacle just not have power because the regular breaker trips. When you reset the breaker do you also have to reset the GFCI receptacle or does the receptacle have power without resetting it by pushing the reset button when you reset the breaker.

There is a difference between the GFCI tripping and having to reset it with the reset button and the GFCI losing power because the regular breaker trips.
 

Jeff Handy

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If the “regular circuit breaker” is an arc fault breaker, they are known for nuisance tripping.

Otherwise, I would replace the fan motor and see what happens.
 

Kat2014

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Yes, it "actually" trips the GFCI outlet and the regular circuit breaker at the box at the same instant.
I have to flip the breaker back on AND reset the GFCI outlet.
 

Kat2014

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The unit is brand new....I bought 2, and the other works fine. Is it common to get a lemon in high end bath fans?
 

afjes_2016

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Lets keep in mind everyone what the OP stated about the fan

"First one was fine. Second one (identical) not so much. I turned the power back on and the fan and lights came on as normal, but when trying to turn the fan off, the breaker pops." Which means the fan runs fine.

This occurs when the OP turns the fan off. So to me this states there is a mis-wire and causing a dead short. Would not matter what type of breaker the OP has installed. A dead short will trip a regular breaker, AFCI breaker, GFCI breaker or a dual function AFCI/GFCI breaker.

Kat2014 please confirm that the fan runs fine but when you go to shut the fan off (turn the switch to off) that is when the breaker trips. If this is the case that when you turn the fan off it trips the breaker you need to check how you wired it. Give us some details of the wiring because it is obvious that you did not wire something correctly when hooking it up.
 
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Kat2014

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I appreciate all the comments, but I cannot give further wiring details at the moment,. We have some storm damage from the system that came through on Thursday night, and I have my hands full taking care of that.

But yes, the fan runs fine, it trips everything when shutting it off. The switch has already been replaced, and I will check the wiring after I get the storm damage taken care of.
 

afjes_2016

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Swap the motors between fans, see if the problem moves with it.
Jeff Kat2014 said the fan runs fine. Read my reply above (post #15). It is when Kat turns the fan off that the breaker trips.
This clearly indicates that Kat2014 did not wire it correctly when hooking it up. There is no need to swap fans or anything else.
 

Jeff Handy

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The problem and diagnosis might be obvious to you, but others with experience have valid opinions and input.

No one appointed you king of the forum, we are free to suggest ideas that have worked for us in similar situations.
 

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