Motor drawing too much juice to start?
Greetings all, this is my first post here and I've got a problem and I hope someone can give me a hand.
I've got an old Century motor, 1HP 1750 RPM and I can get the other info if needed.
It's plugged into a 110v and there's a built in breaker on the machine that houses the motor. I realized it was wired for 220v and it helped to rewire it to 110 but it's basically doing the same thing which is to buzz loudly for a few moments and trips the breaker before it can start itself. If I spin the shaft just a little it will speed up, click, and it will fly at full power and RPM and will be nearly silent and runs perfectly and seems unstoppable.
I took it apart and cleaned it, though it wasn't bad, just a little dusty. not enough to make a difference. There a spring plate on the back of some sort which I think does the clicking and a trigger at the very back of some sort.
There's a wire coming out of this trigger box and is exposed on the top of the motor and there is another wire that comes from inside the motor that comes out the same hole up top. Both are bare and not touching. Just out there. There is a sort of 'clean spot' around this area of exposed wires, implying that there was a housing atop the motor where these wires hooked up to something at on point sometime in the motor's life. I believe the wires are hot too. Well, I'll admit it... I shocked the hell out of myself so I actually know.. heh
What might have been on top of the motor and is it's absence a probable suspect for it's inability to start turning?
I thought about just wiring the motor itself directly to a 220 to continue self troubleshooting but it's about 20 ft away and thought I'd better ask before catching the world on fire or something.
I can post pics if needed too.
It's function was to turn a fan via pulley, the fan being the main part of a big vacuum and filtration setup.
Thanks in advance.
Sounds like you are missing the start cap.
Agree. That bare spot was probably the start cap.
Give me the model number serial number, and frame size. I will see what capacitors it requires and tell you what "mfd and voltage" they should be. I will also give you a connection diagram. It most likely will connect to the 2 loose wires. Do these wires have terminals on them? Are they brown?
You are missing the start capacitor that was housed under the clean spot. You should see two mounting holes for the cover.
The spring plate on the back of the motor is the centrifugal switch. This switch opens when the motor reaches operating speed and takes the capacitor out of the circuit. Easy fix.
The wires are blue.
Serial number is 12F... shortest serial I've ever seen.
and I don't see a model number on it
It also says on the back label:
Service Factor 1.25
Cont. D.P. 40c
Insul Class A
Serial # 12F
Connection Diagram C32536
Yes there are also 2 screw holes up top and the missing section looks like a fat cross so I can imagine it was a rectangular piece with two flaps sticking out on the side to secure it by the screws
I did a search for start capacitors but couldn't figure out what to look for. Any tips?
The motor you have is a proprietary motor that Century built for a customer. Century is now AO. Smith. It was built to their specs, and could just be a different color or a different shaft size. The reason I know is the "spec" number is missing along with a misleading catalog number.
Go to AO. Smith's web site and look for a distributor/service center/partner in your area. Give them the number; EMI 9-302016-01.
They may be able to tell you what cap it uses or they may send you to the customer that had the motor built special for them. They will have this cap on their shelf.
Either way you look at it, ultimately AO. Smith is where you start.
Ps.....Do the blue wires have terminals on them????????????
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