The Great Plastic Emerson Capacitor Transplant

[JW]

Well, I got around to replacing the capacitor on the '81 Emerson this afternoon... the second successful mod on the fan (the first one being the Lasko blades, which are much better quality than the originals). There are some interesting results...

The original capacitor in the switch housing of the Emerson is a 5uf. First, I opened up the inside of the builder fan that came with the apartment, and looked at its capacitor. One wire leading out of it is labeled 5uf, another is labeled 6uf and the third has no label. Both labeled wires go into the pull chain. I left it in there.

Next, I cracked open the switch housing of the 4-blade Tyeb, to find out that it has THREE capacitors. Two of them are 7.5uf and one of them is a 12uf!!! These were wired in different series to the pullchain and up into the motor. I couldn't figure this one out, but I assume it accounts for the differences of speeds on forward and reverse (low reverse was faster than low forward, and high reverse was slower than high forward.)

I cut the capacitors out of the Tyeb (had to, since they were permanently crimped into place) and put the 7.5uf on the Emerson. The low speed went from about 65 RPM to around 80. There was little to no change in speed on medium, and definitely no change on high.

So I put in the 12uf. Again, an increase in speed on low, this time around 100 RPM, but again no change on medium or high. So apparently, the capacitor in the switch housing only controls the low speed.

In looking at the owners' manual, there isn't a capacitor at all in the 42" models, which were 2-speed. There is a "capacitor cover" in the motor housing in all the models, but this hooks up to the reverse switch which is in the faceplate. No rating is listed in the parts diagram for this piece.

I never understood Emerson's pathetically low speed in these year models, especially when medium and high are so close together. So I put the 7.5uf capacitor back in the switch housing for good, and now I have a fan that I can actually feel moving air on low.

Next mod might be using that 12uf capacitor and converting the sucker to 4 speed

[Deleted]

JW said:

The original capacitor in the switch housing of the Emerson is a 5uf.

The capacitor in the switch housing is only for the low speed of the fan. The motor has coils for two speeds (high and medium) and when low is selected the capacitor is introduced into the circuit to drop the medium speed to low. The "run" capacitor is in the motor housing. However I wouldnt change it's value much, the motor could overheat. Changing the low speed capacitor, on the other hand, wont damage anything as long as it still runs. So experiment away.

JW said:

Next, I cracked open the switch housing of the 4-blade Tyeb, to find out that it has THREE capacitors. Two of them are 7.5uf and one of them is a 12uf!!! These were wired in different series to the pullchain and up into the motor. I couldn't figure this one out, but I assume it accounts for the differences of speeds on forward and reverse (low reverse was faster than low forward, and high reverse was slower than high forward.)

.

Possible, but unlikely. More likely that one of them is the run capacitor, one is for medium speed, and the other is for low. The motor is likely one speed but has a smaller coil for reverse.

JW said:

I cut the capacitors out of the Tyeb (had to, since they were permanently crimped into place)

You can remove those crimped connectors without cutting anything. I use a pliers. Helpful when the leads are short as it is.

JW said:

In looking at the owners' manual, there isn't a capacitor at all in the 42" models, which were 2-speed.

There is, it's in the housing. There's no additional capacitor in the switch housing for low speed, the low speed is derived from the motor's coils. I usually add capacitor in the switch housing and make these fans three speed.

JW said:

I never understood Emerson's pathetically low speed in these year models, especially when medium and high are so close together. So I put the 7.5uf capacitor back in the switch housing for good, and now I have a fan that I can actually feel moving air on low.

I like fans with "pathetically slow" low speeds, for gentle circulation and for asthetics. That's why, as a child, I loved variable speed fans, they could go slower than other fans. I often tweak the low speed on my fans to be a slow as I can get and still have enough starting torque.

JW said:

Next mod might be using that 12uf capacitor and converting the sucker to 4 speed

If you can find a four-speed pullchain. Let me know if you do!

[JW]

I tried pliers on the crimps... wires didn't budge. I'm sure I could have gotten them off with more effort... but I knew I wasn't going to put all that stuff back together.

So is the capacitor in the "capacitor cover" (a plastic tube) similar to the one in the switch housing? I don't want to burn the fan up, but I would like to see if I could get the high speed up above 200.

I know the extremely slow low speeds are mainly for aesthetic purposes, it just seems odd that the low would be so slow, and the medium wouldn't be at least mid-range. Same way with the 90s model Originals, which were listed with speeds of 45/160/200.

[Deleted]

JW said:

I tried pliers on the crimps... wires didn't budge. I'm sure I could have gotten them off with more effort... but I knew I wasn't going to put all that stuff back together.

So is the capacitor in the "capacitor cover" (a plastic tube) similar to the one in the switch housing? I don't want to burn the fan up, but I would like to see if I could get the high speed up above 200.

I know the extremely slow low speeds are mainly for aesthetic purposes, it just seems odd that the low would be so slow, and the medium wouldn't be at least mid-range. Same way with the 90s model Originals, which were listed with speeds of 45/160/200.

I dont know what the capacitor cover you're describing looks like, but from the name, there's a very good chance there's a capacitor inside.

The older Emersons (with the plastic blades) had the oil-can capacitors, a silver can with two (sometimes three) wires connected to one end with spade crimp-on connectors. They were connected with a strap to one of the screws on the motor. I believe that both leads going to the capacitor were brown. Now your Emerson may have a different capacitor, being newer . . . I've never taken a wood-bladed Plastic Emerson apart. But it should be obvious once you open the housing, if not, follow any leads from the motor windings that do not go into the switch housing.

As for the speeds thing . . . I used to have a Fasco Charleston in my bedroom. I took it down. Reason? Low speed was fine, but the medium seemed like medium-low to me. I rarely use a fan on high when I'm sleeping, and the Fasco's medium wasnt enough on hot days. I like my medium speed to be 'high' without the helicopter/wind noise. Of course, seeing how slow I like my low speed, a fourth, medium-low speed would certainly be helpful, but I wouldnt use it much.