So I installed a ceiling fan the other day...

Discussion in 'After Hours Lounge (Off Topic)' started by Jason Charlton, Sep 13, 2005.

  1. Jason Charlton

    Jason Charlton Ambassador

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    ... and was wondering what effect a lack of grounding would cause?

    When I took down the old fan, I noticed that there were only 2 wires (black and white) coming out of the conduit in the ceiling. There was no ground wire. In fact, the ground wire from the old fan was simply curled up and not connected to anything at all.

    Is there anything I can do to properly ground this, or will I have to live with the knowledge that it's not grounded and accept the annoying hum that results anytime the fan is on and I dim the lights?

    Is there a danger to the fan motor if it's not properly grounded?

    Thanks for any input you have.

    -Jason
     
  2. Marc_Sulinski

    Marc_Sulinski Supporting Actor

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    Generally, you want to run the ground wire to the metal bracket where you hang the fan. At least, this is what I did. There should be a (possibly green) screw on the bracket. Just attach the ground wire to this screw.

    Maybe someone on this board more experienced with electrical stuff can confirm this.
     
  3. Jeff Ulmer

    Jeff Ulmer Producer

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    If there is no ground wire servicing the box, attaching wires from the fan to the box don't do anything. I can't comment on whether a lack of ground will hurt the motor or not, but I don't think it is the cause of your hum. does this fan have lights, and if so what kind (halogen, incandescent), and what kind of dimmer are you using and what is it dimming?
     
  4. John Alvarez

    John Alvarez Screenwriter

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    The hum is not from the lack of graound. Grounding protects YOU and the motor from overloads.
     
  5. Jason Charlton

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    Thanks for the info... yes, the fan does have lights, three incandescent, 60W bulbs. If the fan is off, I can dim the lights without any noticeable hum. Only when adjusting the fan speed using the dimmer does the hum become louder (I'm pretty sure if the fan is on, the hum is always there, but barely audible if the dimmer is at max). The dimmer is the only thing running to the fan.

    Actually, I was half expecting to find two sets of wires running to the fan - one set from the dimmer (that would be hooked up to the light) and a second that bypasses the dimmer that would be hooked up to power the fan, regardless of whether or not the dimmer was "on".

    Could the hum be the result of both the light and fan being run from the same dimmer? Perhaps the wattage draw is too much for the dimmer to handle?

    -Jason
     
  6. Marc_Sulinski

    Marc_Sulinski Supporting Actor

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    What would cause the hum?
     
  7. Paul Padilla

    Paul Padilla Supporting Actor

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    If I read correctly the fan itself is on a "dimmer" to control the speed. That's where the hum would be coming from.

    Fan motors don't respond well to a variable switch like you would use to dim lights. All of the controls you'll find that are specifically for fans click from one speed to the next to avoid that problem. You can find switches at Home Depot, etc. with one slider to dim the lights and a regular 3 or 4 position speed control for the fan which fit into a single gang electrical box.
     
  8. Jason Charlton

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    OK - I'm starting to think that there isn't a simple solution for me in this case. It stands to reason that any "dual purpose" dimmer would require two sets of wires to run from the switch to the fan - one to control the fan motor and the other to control the lights (though perhaps they could share the same neutral, or white wire).

    I'll have to see if it's plausible to replace the dimmer and (if needed) route additional wires from the dimmer to the ceiling receptacle. When I installed the fan, I noticed that the wiring was inside conduit which may make feeding additional wiring possible with a snake or some such device, but since the fan is on the ground floor of a 2-story house, access from above is impossible.

    Thanks again for the input. I'll make a run to Home Depot sometime soon and see what dimmer options might work.

    -Jason
     
  9. Paul Padilla

    Paul Padilla Supporting Actor

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    Ceiling fans w/lights should have a single 3 conductor wire (Plus the ground) to accomodate the two devices. You're right...they will share the common neutral wire and have two leads to power the fan and the lights independently.

    The other thing you might be able to do if wiring isn't going to cooperate is get a remote control package. It will have a receiver that gets wired to the fan and the light inside the canopy. It is still gets wired to a switch but it only requires one lead. The remote receiver powers the light and the fan separately.
     
  10. Jeff Ulmer

    Jeff Ulmer Producer

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    As you have probably guessed, it is the light dimmer on the fan motor than is the problem. As has been said you need 3 conductor cable up there, or forget the dimmer. Does the fan have speed controls built in and a switch for the light (chains)?
     
  11. Mike Voigt

    Mike Voigt Supporting Actor

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    Some older designs use the conduit itself as a grounding system. There are clear problems with this - the conduit needs to be a complete circuit back to the ground rod, through all of the boxes - but it used to be installed a long time ago. These days it is 3-lead wire or, in this case, 4-lead wire (one neutral, 2 hot, one ground).

    Do your other receptacles/lights all have 3 lead wire running to them? If so, I'd get an electrician to wire it all up correctly, b/c somemone messed up.

    DON'T put a fan on a regular dimmer switch. It is not good for the fan motor.
     
  12. Marc_Sulinski

    Marc_Sulinski Supporting Actor

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    So if I have a fan that has the lights on a dimmer switch and the fan wire on a fan control switch, and I hear hum when the lights are on, what could that be? Is that just the dimmer introducing the hum?
     
  13. Ted Lee

    Ted Lee Lead Actor

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    as already mentioned, it's probably because the fan is on a dimmer. unfortunately, it sounds like you only have one set of wires going from the switch to the fan. so that means you only have one constant power source to control both the fan and/or lights.

    what i would do is simpy replace the dimmer switch with a regular switch ... then use the controls on the fan itself to control the lights (on/off) and fan (prolly a three-speed switch).

    the only way around this is to wire another line to the fan. then you can have one switch control the lights (dimmer) and another switch to control the fan (on/off).
     
  14. Marc_Sulinski

    Marc_Sulinski Supporting Actor

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    I was actually asking about a different setup, one where I have a fan control for the fan and a dimmer for the lights (with 2 different wires).
     
  15. Ted Lee

    Ted Lee Lead Actor

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    i was actually replying to the original poster. [​IMG]
     
  16. Jason Charlton

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    Thanks Ted, you pretty much summed up my options - wire a second line to control the lights and fan separately, or ditch the dimmer altogether.

    Hopefully, I'll be able to do option 1 in the very near future...
     
  17. Ted Lee

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