Re: Help needed wiring an electric motor.

tbaker@xxxxxxxx wrote: 
Hi all,
In my search for wiring information I've come upon this group. Maybe
someone here can help me out.

I'm in the process of heating my shop with an outdoor wood burning
boiler, (it heats my home also).
I just had a squirrel cage fan given to me and I really don't have a
clue as to how to wire it up. I don't even know what it came out of but
here's what the tag on the motor says;

EMERSON    MODEL  K55HXLGF-3701            HP  3/4
VOLT  115                         HZ  60            AMP  11.0     PH  1
R.P.M.  1075/4SP        THERMALLY PROTECTED
PT   NO   51-21459-02              MFG. NO  K92 C
INS  CL   A  AIR OVER CONT             FRAME  48Y

Also over on the right side of the tag it has;

12.5MFD
370 VAC
CAPACITOR

It has 7 total wires, ( one being the green case ground)
the other 6 wires are;
Red
Blue
Yellow
White
Black
Brown

I'm guessing a few things here;
1.  This is a 4 speed motor?
2.   I'll need a 12.5MFD  370 VAC  CAPACITOR?
3.  To get 4 speeds I'll also need a 4 speed switch?

Questions;
1.  How do I wire this thing? (Of course!)
2.  Where do I get the capaciter, (if I need it)?
3.  Where do I get a 4 speed switch, (and approximate price)?
4.  Could I wire it up for 1 speed only?


I'm definately not an electrician. I'm familiar with household wiring
but not the technical terms and what they mean, so you'll have to keep
your explainations simple as best you can.

Thanks in advance! (I just hope I can find this again) LOL! 

Hi,

I very much doubt that this is a four speed motor. I've never seen a four speed induction motor and I doubt they exist. They would be very bulky and probably inefficient, too.

The data plate just gives one speed, so I think this is a single speed motor. 1075 rpm fits with a six pole machine running on 60 Hz. The data plate also mentions thermal protection, so I'm guessing that two of the wires lead to a thermal cut-out. What follows is my best guess about the motor type.

If you have an ohm meter, carefully measure the resistances between the wires which emerge from the motor. Make sure there is a good connection between the ohm meter and the wire. I suspect this is a single speed "capacitor run" motor. If so, I'd expect you to be able to identify three pairs of wires. Each pair should have a fairly low electrical resistance between them, but should not be connected to any other wire.

If this is the case, the pair with pretty much zero resistance between them will be the thermal cut-out (unless it's broken), the pair with the next lowest resistance will be the main winding, and the pair with the highest resistance will be the capacitor run winding. If there are two windings of equal resistance, this motor is designed to be easily reversible and it doesn't matter which is used for the main winding (let me know if this is the case and I'll send you a diagram of the reversing circuit). Connect the capacitor in series with the capacitor run winding. Then connect the capacitor and capacitor run winding (together) in parallel with the main winding. Then connect the thermal cut-out in series with all of this, hook up to the supply and cautiously apply power.

If my guess was right the motor will run. If it runs in the wrong direction, reverse the connections to either the main winding or capacitor run winding (but not both). If it doesn't run, it's a weird kind of motor which will require more investigation, or a dead motor.

Capacitors should be available from motor repair shops (along with advice if you're lucky). Check your Yellow Pages for details.

Good luck!

Chris

.

Relevant Pages

  • Re: Need some electrical know-how
    ... switch to the saw. ... A single-phase induction motor with only one energized winding will not ... or the capacitor can be bad as well. ...
    (alt.home.repair)
  • Re: Is this French motor reversible?
    ... have a switch capable of making sparks. ... reverse the leads of either winding. ... you are describing a permanent split capacitor motor. ...
    (rec.crafts.metalworking)
  • Re: Clue me in on this.
    ... I had a machine with a reversable capacitor start 1 HP motor. ... I found that if you switched the direction without stopping the motor, the inertia of the machine would cause it to keep on running in the original direction despite the winding mismatch. ... If there's no start switch, it's a permanent split capacitor, or PSC motor. ...
    (sci.electronics.repair)
  • Re: Clue me in on this.
    ... Capacitor start motor. ... Capacitor good 2 windings. ... Run winding across line voltage, Start winding across line voltage with capacitor in series. ... If there's no start switch, it's a permanent split capacitor, or PSC motor. ...
    (sci.electronics.repair)
  • Re: Switched Two or Three Speed Three Phase Motor
    ... These can work quite well but need the capacitor value ... (or capacitor voltage tapping) ... the motor speeds but you ...
    (uk.rec.models.engineering)
Loading