Help ID this Tagless Electric Motor?

[NC Fabricator25]

I need to crowd source some help to identify this motor, so I can figure out which machine (of the many waiting) it can power. Was a scrap yard gamble several years back, paid by the pound, less than $20 if I recall. The downside is that it’s missing the cover off the capacitor box and has no nameplate. The good news is it fires right up and somehow I came up with the wiring connections schematic so I know how to wire it up.

The most important things to find out: horsepower and rpm (is a 2 pole or 4 pole)?

What I know: it’s an open drip proof frame, has a 1-1/8” shaft, weighs 87lb and seems to match the blue of Leeson and some Marathons or Centuries. What seems to be different is that it only has the one box for the wiring connections and capacitors. The Leesons, for example, have separate boxes on the motor. I strongly suspect it’s a 5hp, possible a 7.5hp. Eventual use could be a 20” Rockwell Planer, Champion Power Hammer, or air compressor.

Any knowledge on what matches up, or simple ways to figure out the hp and rpm? Thanks!

 

[NC Fabricator25]

Edit to add:

- the color is far more blue in person
- here’s the pic of the wiring connection diagram I deciphered

 

[metalmagpie]

Suggest you first identify the NEMA frame size. With a 1-1/8 shaft it could be 182T or 213 or 215. Google on "NEMA frame sizes".
With no motor nameplate it will be difficult to identify the maker. You're sure there isn't a nameplate that's been painted over?
You can measure RPM with a no-contact digital tachometer (buy/borrow). No idea how you can easily come up with horsepower, sorry.

 

[The Cobbler]

HP probably can be determined by measuring the running amps

 

[NC Fabricator25]

I think I may have found a winner. Did some searches for 5hp ODP in the big brands, same for 7.5hp and so on. Looks like a Marathon 5hp, 1800rpm, air compressor motor spec motor, but in a true HP kind of way and not the inflated HP / “SPL” rating. I may try to find a customer service number to see if a cover plate is available, if not I’m sure I can come up with something that will work. And, I’m a happy camper overall, those specs make it useful for a number of machines so it will have a good home soon.

https://www.regalbeloit.com/products/motors/low-voltage-nema-motors/nema-definite-purpose-ac-motors/air-compressor-motors/5-hp-air-compressor-motor-1-phase-1800-rpm-208-230-v-184t-frame-odp-184tbdw7026

 

[pcmeiners]

"HP probably can be determined by measuring the running amps"
Yes...HP can be determined using ohm's law for the amperage, then comparing amps drawn by similar motors eg. 21 to slightly more than 23 amps will be 5 hp at approx. 230v

 

[Mike Folks]

Leeson or Marathon electric motors would be my guess....

 

[larry_g]

Can you find a Marathon motor parts book and match the Cap sizes to help determine HP? I'm assuming that a 5 and a 7.5hp motor would have a bit different cap values.