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Electrical Installing ceiling fan/light where light fixture is now

  1. May 28, 2018 #1
    After getting through a heat wave this weekend I've decided it's time to look at getting a ceiling fan for our bedroom. Right now there is just a simple light fixture. When I talked to my dad about it, he had some comments that made me realize it's not a straight swap. My house is year 1922 btw.

    1. He said I have to install a new box in the ceiling to support the fan/light weight. This would require access from above. The attic has wood floor boards, but I'd hate to pull a few up if I can help it. Is there anything else I can safely do to keep the same box? A few videos mentioned using a brace with the current light box? Would finding a "lighter" fan/light be helpful?

    2. He said not to reuse the wiring. I'm actually not sure if the wiring is original or newer. The ceiling light is modern. So if the wiring is more modern then I can reuse right? If original from the 20s I need to rewire from the switch? I would hire and electrician then for all this then, but if I can get away with doing this all myself that would be great.
  2. jcsd
  3. May 28, 2018 #2


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    A typical ceiling fans weighs, IDK, about 10 to 15 pounds. All ceiling fans have at least a little wobble when they are running. So you need about a 10:1 static safety factor on the strength of the mounting to be safe. If you can grab the ceiling fan and lift yourself off the floor, then the mounting is strong enough. Generally, the box for a ceiling fan needs to be securely fastened to two adjacent joists, where a box used for lights is nailed to one joist.

    Copper wire lasts forever. If the insulation is cracked, it is failing and the wire needs to be replaced. Electrical connections are a failure point. Corrosion gets in there, resistance increases, it gets hot and starts a fire. I'd be much more concerned about old receptacles and switches than old wire.

    This is about safety. Does this mean that the thread needs to be locked? :smile:
  4. May 28, 2018 #3


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    One way to determine whether the wiring is original or not is if it has a ground wire in addition to the hot and neutral. A ground wire would mean it has been re-wired, since ground wires were not standard in the 20's. Do you have a fuse box or circuit-breaker box? Circuit-breakers are another indication that there has been some updating to the electrical wiring.
  5. May 28, 2018 #4
  6. May 28, 2018 #5


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    Okay, that's in your favor. Do you know if there is a ground-wire?. Another clue is what the wiring looks like. If it is something like this:
    With the wires grouped together inside a vinyl covering, then it was at least no older than the 60's.

    If rewiring is needed, just replacing the switch to light wiring won't cut it. A typical house circuit might look like this:
    Note that one cable supplies more than one light and a number of outlets. If, for example, your ceiling box is like the rightmost one in this diagram, the wiring between switch and box is just a small section of the wiring that has to carry the load.
  7. May 28, 2018 #6
    1st. He is right about support. My place used to be a hospital in the 1940's and I have replaced all lighting with ceiling fans with built in lighting. Cuz I live in the desert.

    My wiring and breaker panels are antique. But my place is supplied by a 3 phase 240 volt high leg Transformer on a pole. < one phase is 180v, hence the term high leg> .

    Me. I just hooked mine up. I used a clamp amp probe like so
    To check what amps were being pulled and compared that with the wire rating and breaker rating.

    I did not over think this. But dwellings are different from locale to locale. Just mentioning how I handled my installs. The mounting electrical box needs to be fastened with wood screws and look approx. like so. https://images-na.ssl-images-amazon.com/images/G/01/th/content_26/Q2_2011/c26-B000DCN8ZY-2-l.jpg
    The wood screws are the important ingredient. Not nails. If you can hang from the electrical box,. The ceiling fan can also.
  8. May 28, 2018 #7
    PS. If ground wire is absent. One can pull one to the panel. Through the whole building using a blow string through the attic. To pull the wire with the string later. Then do your hookups in the attic for just the ground < #12 wire size should suffice > . Then in the panel hook up the ground you just pulled and installed . Then run a like a #4 or #6 cable from the breaker panel to a grounding rod stuck into the ground outfdoors. With a grounding clamp attached to it.

    But being 1920's. I would not be suprised if your place was grandfather claused somehow to not need this. Grounds are there to trip GFI breakers. But a neutral < white wire > should work OK on older breaker panels.

    I'll probably catch flak on this forum for this. But I roll like I do and non of my places burn down. Or catch on fire. I own 2 residences and have rewired both of them.
    You roll like you wish to. I don't live in a what if state of mind.

    I don't leave frayed wires and burnt wire nuts alone. I fix that 1st before I do the above.
    Last edited: May 28, 2018
  9. May 28, 2018 #8


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    I would check if the circuit breaker sizes are correct for the wire sizes connected to them. It's entirely possible that somebody replaced an old 60 amp fuse box with a breaker panel, then installed breakers without regard to wire size.

    If the wiring is old, then have an electrician check for a common neutral. If you have common neutral wiring, then seriously (very seriously) consider replacing all of the wiring.
  10. May 28, 2018 #9

    jack action

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    You can use an "old work" hanger bar to replace your actual electric box with a new one, specifically designed for a ceiling fan. It is installed through the old outlet box hole. Example:


    As for the electrical portion, most fans I've seen require 50-60 W, i.e. the size of an extra small light bulb. Even with the light fixture, they are about 100-120 W total (about a 1 A current). That is certainly not a problem for typical wiring, even for the 1920's. If your wiring cannot support that current, it is most likely not safe for your current light fixture either.
  11. May 28, 2018 #10


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    Maybe. The light fixture should be attached to a junction box already and it may support the weight of the fan. It would be pretty unusual for it not to already have a junction box. The only way to know what you have is to take down the light fixture.
    It will not necessarily require access from above. You should know more when you take down the existing fixture...
    No, it's pretty much all or nothing. Either you could do pull-ups from one screw into a joist or there is nothing there but a bare wire and no junction box (which would be surprising).
    This is the potentially biggest problem. If the wiring is old, yes, I'd recommend replacing it, but I replaced a bathroom fan for an ex without replacing the knob-and-tube wiring (so just because you see a newer light, doesn't mean it is new wiring....). If you have to re-wire, that's a big expense and something you probably can't do yourself if you aren't near the panel.
  12. May 29, 2018 #11


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    I installed 2, both around 30 years ago. I tested the boxes by hanging my full weight from them.
    Like you, the first one I installed was in my bedroom. And being a new homeowner who knew nothing about ceiling fans, I opted for the cheap generic brand.
    BIG MISTAKE in the bedroom!
    It has a very annoying cyclic hum on medium speed, and wobbles A LOT on high speed.
    Needless to say, I never take it off slow speed. Although the box could support my full weight, I can only imagine that it would have shaken itself loose after 10 years and chopped my head off while I slept.

    I later bought a "Hunter" for my living room. No annoying hum, nor noticeable wobble at any speeds.

    I don't really know why you'd need new wiring, as long as it's not the "knob & tube" stuff Russ was discussing.
    But to be sure, like everyone else, I would have to look at it, to give an worthy opinion.

    One simple trick might be to open your circuit breaker box, and see if there's an inspection notice inside.
    I have one, and it lets me know that my "box" passed inspection back around 1971, about 20 years before I moved in.


    Though, upon my inspection, the wiring in the entire house was the original 1945 junk, which I promptly* replaced.

    *Ok, so it took me 5 years...... Long story, so I'll just leave it at that. :angel:
  13. May 29, 2018 #12


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    Just thought of something else.

    If you decide to take my advice and open the breaker box, take a picture.
    If you count the number of white plastic coated (neutral) vs un-coated (ground) wires on those two bottom bars, we might be able to determine how old the wiring is.


    I recommend taking a picture, as, like me, you might want to poke around inside the box to count things.
    There's 220 volts in there. Bad place to be poking around.

    ie. Do not stick your fingers inside the breaker box!
  14. Jun 2, 2018 #13

    jim hardy

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    Speak to the guys at local lumberyard. As @jack action said there are special boxes for fans. They're heavy and need robust support.

    Amen to "No El Cheapo" ceiling fans.
    Best ones i ever owned came from a lighting supply house, a pair of verdigris Emersons that cost about $200 each. I teased Fair Anne about 'overpriced corroded copper ' but first time i turned them on i ate my words. Quiet, smooth, no hum and absolutely no wobble.

    Now - if you want lights on it that are controlled by a separate switch in the wall,
    well that takes another wire or two.
  15. Jun 3, 2018 #14

    jim hardy

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    I always liked the 'old style' Hunters with soooo many poles in the motor, oil bath lubrication and weight probably forty pounds.
    I weighted the blades to arrest wobble. Left a pocket knife laying atop one for ten years and it never moved, found it covered in dust.
    I have to admit though, Fair Anne's high end Emersons outperformed them for absence of sound and wobble.
    Greg - Do some comparison shopping. Ask an electrician where's the best supply house in town.

    old jim
  16. Jun 4, 2018 #15


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    Maybe not. As I mentioned, it's been about 30 years since I installed my two fans.
    The following I just found seems to infer that remote technology may have solved the problem of not having to add an extra power line, and hence, reduced the cost.

    This Old House
    Wed, 12/24/2014
    BillyB1976; "Existing ceiling fan/light combo with only one hot wire?"

    HoustonRemodeler; "A remote control add on package is in your near future. The add on kits use the hot from the switch to power the remote. The remote control then can be installed over (covering) the wall switch so the wall switch stays in the on position, powering the light and fan separately through the remote."

    A. Spruce; "You need separate power leads, one for the fan, one for the light.."

    (edited for brevity)

    Seems to be a difference of opinion.
    This might require some more googling.

    Another option, as Old Jim and I seem to have both figured out that when you replace your lamp with a fan, it's kind of dark when you flip the switch, so you really do need a light switch, is to add a wall sconce near the original light switch. This would require minimal invasive surgery to your house.

    I kind of lazily rednecked this problem in my bedroom by adding a dollar store wall sconce hooked to an extension cord.
    That kind of bit me in the bum, when the rotary switches failed. Now I fumble around in the dark for a lamp on my dresser near the door.


    Best to do it right when you're young.
  17. Jun 4, 2018 #16

    jim hardy

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    Yep. But i do like your style.
    Those old Hunters had pretty good pull chain switches as i recall.
    On new installations i always pull a piece of three wire romex from switchbox to fan box . That gives you two hots, red and black, if you (or the next owner) want separate switches for fan and light.

    Does your PBS carry this show ?

  18. Jun 4, 2018 #17


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    It did. Haven't watched TV in about 12 years, so I'm not sure if "MY HERO!" is even still alive.

    google google google

  19. Jun 5, 2018 #18


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    Any progress? Pictures would be nice. :oldbiggrin:
  20. Jun 6, 2018 #19


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    If the fan starts to wobble, do not ignore it! A friend was part owner in a restaurant many years ago. One of the ceiling fans was wobbling and they rationalized "Oh, it's OK." Eventually the fan ended up on a table. Fortunately the table was empty when gravity took over, so only the fan, the scarred-up table, and a chair needed replacement. Oops!

    (I don't recall if there were any customers in there at the time.)
  21. Jun 14, 2018 #20


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    Reminds me of when my wife and I stayed at a place called "Pine Cone Cabins" in Julian, CA, about 14 years ago. The cabins were very rustic, with accoutrements consisting solely of a ceiling fan and a radio. The only v

    The ceiling fan was so wobbly we couldn't run it any faster than its slow speed. The screen door had screening only on the lower half, which I guess was intended to keep out wingless bugs that couldn't climb up to the open part of the screen door.

    Even though the cabin was situated at about 5000' in elevation, it was summer and still pretty hot. With only one window and a useless screen door, I decided to see if I could tweak the fan blades so it could run at a higher speed. Some of the blades were at different angles, and some were rotating in a different plane. After working on the fan for about a half-hour, I was able to get approximately the same angle on all blades, and to bend the brackets so that they mostly rotated in the same plane. It wasn't perfect, but we could at least run the fan at its medium speed, allowing us to sleep without being covered in sweat.
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