12" ge pancake, 4 wing 10 wire cage ak form C

[Randy Pierce]

Not ever seen this, but this one has a 10 pole motor, full fluted base, and looks to be all original.  Tremendous start torque, but won't rpm over maybe 6 or 700 if that, and growls horribly.  If I take voltage down to around 60 it runs quiet same rpm and draws 46 watts.  At 60 volts, it still has awesome start torque, more than I could ever imagine.  My thoughts say the rotor is the wrong one for the fan.  If voltage is pushed up to 120, it then draws 200 watts and with the growl you never want to hear.  The rotor lams are straight cut, same as my type D, 4 pole cake, which of course has only enough torque to start on full voltage, and then only barely.  I've checked each pole with a small screwdriver, and each has the same magnetism.  I appreciate any thoughts on this, 

Thnks Randy

[Michael Rathberger]

It's a high cycle motor, 125 or 133, I forget. The tag should say. Lower voltage is better, I wouldn't run it at 120. 

[Randy Pierce]

Michael, thx! 

I didn't look past the voltage which is 100-115.  Sure enough the cycles are 125-140.  Likely explains why the rotor shaft and bearing are barely worn.  I'll look to find what country this might have been built for, and look also for a way to get it back to 60 cycles.  If you have more info, and want to share it, I'd be thankful!

Randy

[Paul Michael]

133 and other regional frequencies were in parts of the US up until at least the 1940s.... Unless you found it abroad, no reason to think it's *not* a US model...

 don't have one in front f me to look at, but if the stator is 10-pole, I'd expect that the rotor should have around ~20 divisions. If it's the same as a 'regular' pancake rotor, then it is likely wrong.... 

But: @Kim Frank will be able to give you a definitive answer on this. 

Edited October 17, 2023 by Paul Michael

[Michael Rathberger]

There's two ways to run it properly. A frequency converter to up the cycles or replace, as Paul said, both the rotor and stator with a 60 cycles setup. I have a 1900 version, bought out of NWI/ Chicago. My assumption was always the steel mills may have used different current.

[Kim Frank]

GE's first fans were 52 or 104 volts and 125 cycles. 60 cycles wasn't introduced until 1896. In the grand scheme of things with GE, that isn't an unusual voltage/cycles for early fans for domestic use. Within my collection of cakes, I have 52v 125 cycles, 104v 133 cycles, 52v 60 cycles, 190/220v 60 cycles, BTH 200v 100cycles (a six pole stator) for use in Eastern Africa, 100v 42 cycles (Egypt) along with 125v 40cycle brushed motor. Enjoy the fan as is, not as a daily runner, but as an unusual Pancake. I can't say that there's any difference in rotor divisions between the 60 cycle and 125/140 cycle, only because I've never paid any attention. I'll take a look today or tomorrow and see.

[Randy Pierce]

Thanks Kim. 

Not surprising that so many voltage/cycles were tried and used until a standard got settled on.  This one does run quietly on around 40volts drawing only 30 ish watts, and has excellent starting torque even at that voltage, so it can be used carefully.  I'll certainly be careful with this one. 

May want to check out articles on Charles Proteus Steinmetz and his part in the early years of electric generator design,  and be amazed how he handled a problem that no one could figure out.

[Kim Frank]

No difference in rotors for 60 cycle and 125/140 cycle motors. Division count is 37.   The type AK form C is 1903. There are a total of 9 fans should someone choose to focus on collecting these models, and that's just a/c models. First Variant is full rib base, four struts, 10 wire cage, cast brass blade hub. This is true for 12 inch trunnion and solid frame models plus the 16 inch. Very first trunnions might be type AD before becoming AK. Second variant is full rib base, three struts, either 8 or ten wire cage, and either cast brass or stamped brass blade hub. Third variant is half rib base,  three struts, same blade and cage combos as 2nd variant All cages are pinned rear ring. 1904 1st variant same as '03 third variant. 

[Gary Hagan]

Are there not 60 cycle “Lynn works” 10” models that have surfaced. Would they have been available in 95?

[Kim Frank]

In the survey, there is nothing but 125 cycles prior to '96. Of the Lynn's in the survey for 1896, three are 60 cycles. One of those is in the Museum. In the Everest report, he states the "96 motor "was wound for 60 or 125 cycles; a new 4 pole punching was developed for low frequency. It's details were the same as the 1895 10" motor." I would assume he meant that the details were the same as the 4 pole motor in '95.

Edited November 9, 2023 by Kim Frank

[Randy Pierce]

Thanks for the added info.  The electrical engineers were  certainly on a quest way back then