0

So I just bought a new home and I am replacing some of the outdated ceiling fans. I have done this many times before. However in one room the fixture wasn’t working right. The bulbs kept burning out, so I bought a new fan. It is a single pole light switch for power on and off,(there is a second switch in the wall for a half hot outlet in the room), but the fan/light also has a remote. When I took the cover off there were two cables coming in--one three wire(B,W,G) and the other is a four wire (B,W,R,G).

The first thing I notice is that the ground wire from the fan bracket and down rod is not connected to the ground wires from the power supply. Instead they have both grounds coming from the cable twisted and then one loop going around a screw!

The wire configuration I don’t get it, is as follows.

Black wires from 4&3 wire are connected together.

The Neutral wires are connected together and then twisted with the wire from the remote receiver that says AC in N.

The red wire is connected to the receiver AC in L wire

On the output side of the receiver It is blue to blue, black to black and white to white back to the wiring harness from the unit.

Is this correct?

I’m installing a Merwry fan from Home Depot that also has a remote. Do I connect the wires in the same manor other than connecting the ground wire.

Thank you in advance for your help

2
  • The new fan you bought should have a wiring diagram on how it is connected up. Just guessing now, but usually with recent built houses, the three wire cable should be power from the panel and the four wire should go/come from the switch, black be live/hot and red be switched hot. Ground wire in cables usually not counted, known it is there. See the instructions for how the fan is connected to a switch.
    – crip659
    Dec 3 '21 at 14:05
  • Did you ever figure out why the bulbs were burning out? Were they incandescent bulbs and if so, do you own a voltmeter? Can you tell us about the wiring in the switch box? Dec 3 '21 at 18:15
0

Conventional US terminology is that a black/white/ground cable is referred to as a 2-wire or /2 and a black/white/red/ground cable is referred to as a 3-wire or /3. That is because grounds are always (in normal residential fixtures, switched, etc.) (a) always present (except in very old houses or metal conduit) and (b) always all connected together. Connected together should be either to a screw in a metal box, to a screw on a device or using a wire nut to connect 2 or more grounds together.

So you have a /2 and a /3. There are two reasons for a /3. One is to have two switched items (e.g., light and fan in the days before remotes) and the other is to include neutral. Based on your description, you have a single switched hot and you have neutral.

  • /2 = incoming from panel (or elsewhere in the circuit)

Black = hot, connected to the other hot White = neutral, connected to the other neutral and to the device (in this case, fan/light receiver "N")

  • /3 = switch

Black = hot, connected to the other hot White = neutral, connected to the other neutral and to the device (in this case, fan/light receiver "N") Red = switched hot, from the switch

Your current (pun intended, of course) switch does not use neutral. If you swap it for a timer/motion sensor/dimmer/smart switch/etc. then it may require neutral. If you open up the switch box, you should find the white wire capped with a wire nut and the black & red connected to the switch. If you ever decide to put in a smart/etc. switch, you MUST make sure it is compatible with a fan.

Replacement should be straightforward. I picked one Merwry fan with light/remote from Home Depot and the manual says:

Receiver to house supply wires electrical connections:

  • Connect the black (hot) wire from the ceiling to the black wire marked "AC in L" from the receiver (L).
  • Connect the white (neutral) wire from the ceiling to the white wire marked "AC in N" from the receiver (L).
  • If your outlet box (1) has a ground wire (green or bare copper), connect it to the fan ground wires; otherwise, connect the hanging ball (E) ground wire to the mounting bracket (B).

The only change is that you will use the red wire from the /3, not the black wire. The instructions really should not say "black wire" because while white is nearly universal for neutral (can also be gray, but that is relatively rare), the hot wire can be:

  • Black - standard for an old-style switch loop or for a simple panel->switch->fan installation
  • Red - standard for a newer switch loop (which you have) that includes neutral
  • Yellow, Blue or any other color except White, Grey or Green - unusual but legal and can happen in conduit very easily.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.