Emerson 26646 question

[Trevor Andersen]

So I've mostly finished up the work on this but wanted to make sure the operating specs are correct.  It runs at 1.41A, 117V, 118W on high.  On medium it is 1.38A, 116.5W. On low it is 1.36A, 116W. Are these numbers close to correct or not? I couldn't find any posts on the old forum detailing it for this model and I am uncertain what models are comparable to use. 

[Lawrence Smith]

Like I mentioned On Facebook, those are high, 12” Emerson fans run 1amp or less in the 21-29 series. It’s the same as an oscillator version 27646, you might have it mis-wired at the switch 

[Stan Adams]

Way too high, as Lawrence said, a general rule of thumb on a 12" fan is in the 60 watts range.

[Tristan Crider]

Search the old forum for correct wiring diagrams. 

[Patrick Ray]

Here's a drawing by John McComas. Did you take any head wire readings? 

Edited May 19, 2022 by Patrick Ray

[Trevor Andersen]

2 hours ago, Patrick Ray said:

Here's a drawing by John McComas. Did you take any head wire readings? 

 

Yes. I have 114.7, 93.1 and 21.6.

I am thinking it must be a bad speed coil. I tried swapping all the wire combinations and running it. The readings on the kill-a-watt don't change. It's running at around 1.39 amps regardless of wire placement. 

 

Edit: Actually I found 2 combos of wire placement that got the amps down to .87 but the fan needed help starting to spin and was really underpowered. The watts also remained high but less at around 85-90w

Edited May 19, 2022 by Trevor Andersen

[Trevor Andersen]

I just tested the speed coil by putting one lead on the meter from wire from the coil and each of the speed contacts. High was 0 ohms, medium was 2.2 and low was 3.0. That seems expected if I am testing it correctly. 

[Trevor Andersen]

Could this high amperage/wattage be caused by some contact between wires in the stator intermingling from the aux common main? If so I will soak it all in Sprayon and see if I can fix it. I just figured with the leads giving me a clear high medium and low ohms reading it meant the segments were sufficiently insulated. 

[Thomas Newcity]

3 hours ago, Trevor Andersen said:

I just tested the speed coil by putting one lead on the meter from wire from the coil and each of the speed contacts. High was 0 ohms, medium was 2.2 and low was 3.0. That seems expected if I am testing it correctly. 

From the flying wire on top of the coil to each of the contacts, there should be resistance.  Your choke is either shorted out or you are on the wrong wire.  From the High contact to the flying wire on top is the phase shift winding for the starting and should be showing a resistance of 6 or 7 ohms.  

Edited May 19, 2022 by Thomas Newcity

[Trevor Andersen]

2 hours ago, Thomas Newcity said:

From the flying wire on top of the coil to each of the contacts, there should be resistance.  Your choke is either shorted out or you are on the wrong wire.  From the High contact to the flying wire on top is the phase shift winding for the starting and should be showing a resistance of 6 or 7 ohms.  

Thank you for the info. I will try comparing different wires. This fan looks like it has been tinkered with quite a bit so it's possible someone resoldered the wrong leads from the choke coil to the switch.

Edited May 19, 2022 by Trevor Andersen

[Thomas Newcity]

1 hour ago, Trevor Andersen said:

Thank you for the info. I will try comparing different wires. This fan looks like it has been tinkered with quite a bit so it's possible someone resoldered the wrong leads from the choke coil to the switch.

Trevor, If you have the time, please post a pic or two of that speed control.  

[Trevor Andersen]

Well looks like I will be varnishing and wrapping the coil and ultrasonic cleaning the lamenations. Some of the coils were showing conductivity and not insulated any longer.

Edited May 19, 2022 by Trevor Andersen

[Trevor Andersen]

3 minutes ago, Thomas Newcity said:

Trevor, If you have the time, please post a pic or two of that speed control.  

I already disconnected the coil. Looks like a hairline crack forming in the plate so I'll reinforce that while I'm at it. 

[Trevor Andersen]

Oh I just noticed my switch is for a 24646... is that the problem? 

[Mark Olson]

At this point, you are in too deep to save the coil. It must be rewound. Count the turns between every tap and make a new coil.

If need be, put it all in a box and send it to me and I will rewind it, or perhaps some other member here would be willing to do so. Just don't destroy the coil any further unless you are confident. They can be hand wound, I have done that. You need new magnet wire of the same caliber,or gauge, as the old wire. Wind the new wire around a form of the same dimension as the inside of the old coil. Bring the speed taps out at the appropriate turns count (you must count the turns of the old coil).

[Trevor Andersen]

14 minutes ago, Mark Olson said:

At this point, you are in too deep to save the coil. It must be rewound. Count the turns between every tap and make a new coil.

If need be, put it all in a box and send it to me and I will rewind it, or perhaps some other member here would be willing to do so. Just don't destroy the coil any further unless you are confident. They can be hand wound, I have done that. You need new magnet wire of the same caliber,or gauge, as the old wire. Wind the new wire around a form of the same dimension as the inside of the old coil. Bring the speed taps out at the appropriate turns count (you must count the turns of the old coil).

I might have to rewind it. Haven't done a choke coil before just a few 2 and 4 pole motors. I think I have the right wire left over but will have to check with the micrometer. I'm trying to varnish it and bake it on my bench power supply once first and see what readings I get. If it can be fixed that way it only loses me a little time. But I am curious whether this is even a compatible switch assembly. 

[Stan Adams]

Yes a 24 series is the same choke coil. 27 series back interchange. 28 & 29 series are different.

 

[Trevor Andersen]

I'm waiting for some 26 AWG wire to arrive tomorrow to rewind it. What should I use to replace the fiber plate for the lamenations, also did it have fiber on both top and bottom or not? It crumbled to pieces upon disassembly. I have cork gasket material or fish paper. I could order a sheet of the red fiber too. 

[Thomas Newcity]

The fiber plate at the bottom is not necessary.  The top has a single metal plate which appears to be in your pics of the laminates.  

[Trevor Andersen]

Wound the new coil. Looks pretty good for numbers I think. Just to make sure, which Ohm value connects to which speed?

Also. Do I need to varnish the lamenations or no? 

 

Edited May 25, 2022 by Trevor Andersen

[Mark Olson]

That looks good. I varnish the winding as it helps hold the turns in place.

I also do varnish the laminations while they are loosely assembled, then tighten the stack after it dries a while, because it adds some electrical insulation value between the sheets and helps prevent alternating current buzz.

Edited May 25, 2022 by Mark Olson

[Trevor Andersen]

4 hours ago, Mark Olson said:

That looks good. I varnish the winding as it helps hold the turns in place.

I also do varnish the laminations while they are loosely assembled, then tighten the stack after it dries a while, because it adds some electrical insulation value between the sheets and helps prevent alternating current buzz.

Ok I'll do that then. Does the lowest Ohm value off of the coil connect to the high speed contact or the one with the highest value? I know above Tom said the "high" contact to the top wire should be 6-7ohms. I just want to clarify that means high speed not just highest value lead. 

Edited May 25, 2022 by Trevor Andersen

[Mark Olson]

 

from the flying lead (6 or 7 ohms) to the high. Next resistance more (8 or 9 ohms from the flying lead) medium, and highest resistance (12 or 13 ohms from the flying lead) to low speed. Or thereabouts. so 2 to 3 a couple of ohms, from 1 to 2 an ohm or two, and (1 to 3) = (2 to 3) + (1 to 2). It really isn't as confusing as it sounds, remember that the coils are on a choke which presents an impedance to alternating current and the actual ohm readings are not as important as the turns count. The ohm readings merely give you a reference to what coil has the most turns on it.

[Trevor Andersen]

Well I got it working and a difference in speeds but I think I need more turns. On high it runs at 87 watts, 1.15 amps, on medium 60 watts, .91 amps, and low 52 watts .84 amps. Where do I increase the turns? Id think it would be I need to increase the turns by about 40 from the start to the high speed tap. That would increase the ohms on all of them. I had counted 175 turns from start to the high speed tap. So I'd think that might be enough to get 87 watts closer to 60-65. 

Edited May 26, 2022 by Trevor Andersen

[Mark Olson]

4 hours ago, Trevor Andersen said:

Well I got it working and a difference in speeds but I think I need more turns. On high it runs at 87 watts, 1.15 amps, on medium 60 watts, .91 amps, and low 52 watts .84 amps. Where do I increase the turns? Id think it would be I need to increase the turns by about 40 from the start to the high speed tap. That would increase the ohms on all of them. I had counted 175 turns from start to the high speed tap. So I'd think that might be enough to get 87 watts closer to 60-65. 

Excellent! Personally, I'd call it good. Re-check your power readings at 110-115 volts and see if you are closer to what you are aiming for. Of course there is nothing wrong with experimenting with the choke to see if you can bring the power down and adding turns to the phase shift winding is probably where to begin since you are trying to bring the power down across the board.