A couple questions about my STH-10

[Wdr]

Hello all, I have recently made my first major siren purchase and have couple questions. I bought a partially disassembled Federal Signal STH-10 with a 7.5 hp three phase motor for $120 dollars at a local auction. The motor was disassembled and upon further inspection it is obvious the windings are fried. My questions are 1. Is the motor proprietary or is it a standard frame size , and does anyone know what frame it is? ( I realize having it re-wound is an option). 2. I am in the process of trying to pull the rotor, am I correct in my understanding that I use the two threaded holes in the rotor with a puller to remove it? Also, I don't see any set screws, and noticed the motor shaft is internally threaded. Is there meant to be a bolt threaded into the shaft to retain the rotor? Thank you all , I have been reading on this site for awhile and I hope I can provide assistance to others in the future.

[Wdr]

I have made progress! I got the rotor off with liberal use of PB blaster, a gear puller, hammering, and a propane torch. It was pretty stuck for how clean it looks. I am pretty sure the motor burned up because of the bearing. It sounds pretty horrid when you spin it by hand and I can see marks on the rotor, so there was enough play to allow the rotor to rub. So my question about the motor still stands.

[CDV777-1]

I think rewinding and new bearings would be the way to go with the motor because then you don't have to match-up shaft length/size and fit to the siren stator etc.

[Wdr]

Okay thanks , I'll see how much it costs, also might look at the local scrap yard and see what I can find.

[Wdr]

Also, it looks like there would be a bolt in the end of the motor shaft to hold the siren rotor on. How would it be secured so it doesn't unscrew?

[nathancovey]

Is that a Marathon motor?

[Wdr]

Not sure, all the tags say federal signal. Let me get some more detailed pictures of the motor in specific.

[nathancovey]

Why don't you have someone rewind the motor and put new bearings in it?

[Wdr]

Motor pictures.

[Wdr]

I will go with a rewind when I get the funds together, was just checking because I can find used three phase motors cheap. And a 7.5 hp face mount motor is relatively common.