Ceiling Fan Blog Entry Part II – Mapping Those Switches

First Blog on this topic, see:

Repairing Ceiling Fans, some necessary points.

A home, from 1935, needing rewired for safety. We bought the house to live in, selling our previous house, that we also had rewired. The 1935 Home had 5 Modern Ceiling Fans, all mounted in unsafe ways. The Electrician Modernized the Wiring and Work Boxes for the Ceiling Fans. Since we moved in, 3 of the 5 Fans stopped working or were working poorly.

If repairing Fans, as you progress, take pictures with your Cellphone so you know where the wires go. Be sure the Images are clear, and show various angles of the things you are working on.

This is the last of the malfunctioning fans. WITH POWER TO THE CEILING FAN OFF, I Removed the Bulbs, the Glass Shades, and Removed the bottom cap of the Light Kit. The Fan Speed and separate Light Pull-Chain Switches are found within, as well as the Capacitor. I expected to find a bad capacitor, but physically, it was in good shape. I removed and tested it with a Multimeter that measures capacitance, and the values are off, but not significantly. I intend on replacing the capacitor when I have the chance, but it’s not the reason the fan wasn’t running.

My attention turned to the 3 Speed Fan Pull-Chain Switch, Off, High, Medium, and Low Speeds, and discovered it was not functioning correctly, the Chain Pull was not Indexing the Contact Hub in the Switch correctly or reliably. I needed to Map-Out the connections. The Switch has Terminals L, 1, 2, and 3.

Terminal 3 goes to the Motor, L comes from the Reversing Switch, and 1 and 2 are connected to the Capacitor. With the POWER OFF, I Removed the Switch Barrel Mounting Nut, pulled the switch down from where it was mounted. The Switch Connections are of the Quick Wire type, the wires are inserted and held connected by a Flat Spring Metal Tab. Insert a Cake Tester (that’s what I used), Thick Safety Pin (I also used this), or Similar slim metal object, along the wire into each terminal, it depresses the Tab, releasing the Wire, repeat for all 4 Terminals.

I tried Mapping the Switch with an Ohmmeter, but the contacts were not reliably being indexed. I suspected the Chain-Pull Drive on the switch, but it’s not malfunctioning. Likely the wear in the Base of the Switch for the Contact Hub (Cam) was permitting the HUB to be out of alignment of the Contact Wipes. So I took the switch apart, it was a little struggle, but I was successful.

Switch 1-1

Switch 1-2

Switch 1-3

Switch 1-4

The Contact Hub is Indexed 90 Degrees with each pull of the Chain (when it works correctly).

Contact Hub Bottom

Contact Hub Top

Improved Contact GIF

Terminal L is in the Upper Left Position, Terminal 1 in the Upper Right.

Terminal 3 is in the Lower Left Position, Terminal 2 in the Lower Right. 

In the Animation above (and other images in this Blog entry), Discerning Eyes might notice that Contact 3 (or other contact) is Pulled Away from the Hub in certain frames. Either the Hub is not Centered, or a Wire needs to be Landed under the Flat-Spring for Terminal 3 to Put more Tension on the Contact Arm. When Mapping the Switch with it disassembled, just pay attention whether the Metal on the Hub is there (Connection) or if the Plastic is under the Contact Arm (No Connection). Doing this by Ohmmeter, Insert Open-Ended Wires into the Spring Clips, you can actually use them for taking the Resistance Measurements (Continuity).

Rotating the Contact Hub by hand, I was able to Map-Out the Switch, as follows:

L+1+2 = Off

L+1+2+3 = High Speed

L+2+3 = Medium Speed

L+1+3 = Low Speed

L is from the Reversing Switch. 3 Goes to the Motor.


With Contact 3 not having Continuity to Contact L, either by Looking at it from a Disassembled Switch, or using an Ohmmeter for Continuity, Proceed as Follows:

Either Pull the Chain to Turn the Contact Hub in the correct direction, or see which way the Hub is Rotated if the Switch was still assembled, and manually turn the Hub 90° for each speed and off (i.e. 4 times on a 3 Speed Switch including Off) . It seems to me that, in use, the Contact Hub shouldn’t rotate backwards, but Disassembled and Loose, it may, so use care to turn it the correct way :

• If 3 has no contact, the Fan is Off, no Power to the Motor. Look at the rows of numbers above, only one doesn’t have a number 3.

Turn the Contact Hub 90° for High Speed, with L connected to 1, 2, and 3. (Both Capacitors Connected)

Turn the Contact Hub 90° for Medium Speed, L connected to 2 and 3 (Connects Only One Capacitor)

Turn the Contact Hub 90° for Low Speed, L connected to 1 and 3. (Connects Only Other Capacitor)

And the Next 90° Turn returns to Off (No connection to 3). 

A1

B


When I started the project of Repairing the Ceiling Fans, I ordered 2 Switches from Amazon, works on Most 3 Speed Fans, except mine, apparently. The Amazon Ad was truthful, it included the Drawing I needed to see if it would work with my Fan, but I didn’t understand this Mapping.

The First Fan I repaired had a good capacitor, but the Speed Selector Switch had a broken Mounting Barrel, but functioned electrically (In Use, you couldn’t pull the chain though, it would catch in the Mounting Hole on the fan). I was able to use an Ohmmeter to Map it out, and purchased 2 of the correct switches from Ceiling Fan Parts

The Second Fan repaired, the switch was OK, but for Shitz and Giggles, I decided to Map it out, and guess what, it was like the switches I ordered from Amazon. So, since I had a new switch already, I used one of those 2 and replaced the original switch (and I had to order a replacement Capacitor from Ceiling Fan Parts since the one in it was burned up and melted somewhat).

The Third Fan – I had ordered 2 Pull-Chain 3 Speed Ceiling Fan Switches from Ceiling Fan Parts and only used 1 to repair the First Fan. So I had a spare. After Mapping it out, it was identical to the switch I needed for my Bedroom Fan, so that was put to good use.

Ceiling Fan Parts maps it as follows –

Remember the Motor Lead is 3

L is the Power from the Reverse Switch

They don’t Map the Off Position:

OFF

ON 3+L+1+2

ON 3+L+2

ON 3+L+1

and below is how I mapped it, repeated from above:

L+1+2 = Off

L+1+2+3 = High Speed

L+2+3 = Medium Speed

L+1+3 = Low Speed

So, they are the same. The Off Position has no connection to Terminal 3, i.e. the Motor Connection.


With the New Switch installed, I carefully reassembled the Ceiling Fan, making sure electrical connections are made well, not exposing strands of wire, and not pinched during reassembly, and with the Ceiling Fan Light Kit closed up and secured, replaced the glass shades, the lightbulbs, and powered the fan and put it through it’s paces. After over a year of not working right, all 3 fans have been returned to service.


Author: Dr-Artaud

A Doctor that is not a Doctor, but named after a character in the movie "No Such Thing", as is the Avatar.

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