104/208 volt single phase motor

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
Occupation
Electrician
Anyone ever seen such a thing? I've got one here, just never seen that on a data plate of a motor before. There is no question other than that, I won't be using this motor, probably just yard art.
 
Most single phase dual voltage motors are simply made with two Main windings that are put in series for the higher voltage and parallel for the lower. When the dual voltage is 120/240V, that is simple and useful. But if someone wanted a motor TRUELY designed to operate at 208V, then indirectly, the lower voltage will end up as 104V. The lower voltage rating is not useful for anything though (outside of parts of Japan maybe...)

What MOST motor mfrs do however is to just design the windings such that the 230V setup is OK down to 208V.
 
Found this brief bit on century motors:


The date code system mentioned doesn't seem to match with the serial number of mine. 🤔 But those date of manufacturer codes started 1938 according to the article. Found a picture of another one with a serial number similar to mine (a bit higher number), article says date of manufacture around 1910.
 
The same ratio of 230/240 would put 220 util. at 211 so it does not exactly line up. I have seen a lot of motors from that era that were stamped 110/220/440 volts on the nameplate but never anything else.
 
Anyone ever seen such a thing? I've got one here, just never seen that on a data plate of a motor before. There is no question other than that, I won't be using this motor, probably just yard art.

There are some of these out there that are still used today. On 120V.
I’m inclined to agree with Larry in post 11.
 
Anyone ever seen such a thing? I've got one here, just never seen that on a data plate of a motor before. There is no question other than that, I won't be using this motor, probably just yard art.
Nope and where you find such a transformer power source for 104 volts perhaps changing taps stepping down from 120 to near 104 volt secondary although not good for the transformer? Of course running the motor at common 208 volts would be the best option
 
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