How do I troubleshoot this fan?

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nealtw said:
You turn off power and check the continuity. but first you disconnect the wires so you don't get a back feed reading.
https://www.youtube.com/watch?v=HaIszMlrQNE
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That was a great video and doesn’t apply at all to what would be produced with 120V home wiring. The video produced an arc flash of 25,000 amps according to the title.

When you put a meter set to AC Volts and on a setting that has a range higher than the expected voltage across a hot point and say the ground wire there is no load in the circuit to regulate the current that is the worst case for potential arc flash as it will instantaneously draw as much as the transformer on the pole could provide in the case of a dead short. In the case of fuses they will heat and blow quickly in the case of a circuit breaker they will hopefully open. Huge inrush currents have been known to weld a breakers contact shut. With the fan wired into the circuit the fan is a load and would regulate the amount of current that could go thru the circuit to maybe 2 amps.

Say the failure wasn’t the switch and the fan had somehow developed a dead short inside it and removing the switch and touching the wires together would crowbar the circuit. Just as touching a jumper between the screws to test the switch. Doing the voltage tests will tell you the switch is bad or a bad connection as in the back stabs. You can then take the switch out and check it for continuity with a different setting on a multimeter and determine if it was good at the screws and not the back stabs or just buy a new switch and feel safe it won’t cause a dead short when you flip it on. My dad used to carry a 60w lightbulb with pig tails and clips. He would have taken the fan down as suggested and clipped the bulb on for a load that would both tell him the circuit worked and also regulate the current when putting the power back on.

Nothing wrong with having some load on a line IMO.
 
bud16415 said:
That was a great video and doesn’t apply at all to what would be produced with 120V home wiring. The video produced an arc flash of 25,000 amps according to the title.

When you put a meter set to AC Volts and on a setting that has a range higher than the expected voltage across a hot point and say the ground wire there is no load in the circuit to regulate the current that is the worst case for potential arc flash as it will instantaneously draw as much as the transformer on the pole could provide in the case of a dead short. In the case of fuses they will heat and blow quickly in the case of a circuit breaker they will hopefully open. Huge inrush currents have been known to weld a breakers contact shut. With the fan wired into the circuit the fan is a load and would regulate the amount of current that could go thru the circuit to maybe 2 amps.

Say the failure wasn’t the switch and the fan had somehow developed a dead short inside it and removing the switch and touching the wires together would crowbar the circuit. Just as touching a jumper between the screws to test the switch. Doing the voltage tests will tell you the switch is bad or a bad connection as in the back stabs. You can then take the switch out and check it for continuity with a different setting on a multimeter and determine if it was good at the screws and not the back stabs or just buy a new switch and feel safe it won’t cause a dead short when you flip it on. My dad used to carry a 60w lightbulb with pig tails and clips. He would have taken the fan down as suggested and clipped the bulb on for a load that would both tell him the circuit worked and also regulate the current when putting the power back on.

Nothing wrong with having some load on a line IMO.
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OK I will accept that argument but I have never seen that in instruction.

But to the other side of the problem. The OP was told to check the switch with out enough info and then then he took the fan apart, with power still on
and the switch was the problem.
No body explained to him why he would get 120 reading on one screw and something less on the other.

So as you suggested there was a dead short in the system, the breaker would already be tripped so jumping the wire would have no effect.
 
IMO when a breaker is activated in that manner after the problem is solved it wouldn’t be a bad idea to replace the breaker. In a second hand home you don’t get the history and anything is possible. The fan could have shorted and popped the breaker and did in the stab connections at the same time. The owner could have flipped the switch off reset the breaker and never turned it on again. You just don’t know. If I remember right the OP wasn’t even sure that was the switch in the beginning. I would have started at the switch and seeing only one set of wires coming in known the power came from the location of whatever it controlled. Checking the switch with a meter would have been all that was needed. Unless turning it on or replacing it popped the breaker again.
 
Having a meter in hand does not make an electrician, it's pretty clear that John does not have a full grasp on how this stuff works.

He was told to check the switch and the switch failed the test, no one told him to change the switch.
 
slownsteady said:
You guys are using the meter two different ways. Get it together.
Neal; where did you get that video? From the 1950's?
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Yep it was from the 50’s OHSA won’t let you ground out a 25,000 amp power source just to make a safety video these days.

Ahhh for the good ol days. :nono:
 
nealtw said:
Having a meter in hand does not make an electrician,
Click to expand...
Most of the builders here have an easy rider rifle rack with a 4 foot level hanging from it in their truck and that makes them a contractor.

I always figured a meter and a roll of black tape and you were good to go as an electrician. :hide:
 
bud16415 said:
Most of the builders here have an easy rider rifle rack with a 4 foot level hanging from it in their truck and that makes them a contractor.

I always figured a meter and a roll of black tape and you were good to go as an electrician. :hide:
Click to expand...

And a plumber knows that crap runs down hill and payday is every other friday
 
bud16415 said:
Not sure about Canada but here that’s only a union plumber. :eek:
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Used to take equipment into industrial plants and we had you use their sparky to wire us into a box, we used tell them we would turn on the breaker when we needed it so we could check there work,
They always knew the white went to neutral, with 3 wire 240, guess where they put the green:down:
 
Before reconnecting the fan, should I attach the two loose green wires to each other?
 
All of the ground wires should interconnect as well as any metal parts (junction box and fan housing). You can use the J-box as the common connector; i.e. all the bare wires are fastened to it. or you can get them all into a wire nut. Include a bare wire from the J-box if you choose to do it this way.
 
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