AC MOTOR WIRING HELP??

[Jason]

I have a fan and motor i baught from an auction and need help wiring
it. The info on the motor is as follows:

Skurka Engineering Co.
Motor, AC
Volts 115
Amps 0.5
H.P. 1/50
Phase 1
HZ. 60
R.P.M. 3300
Cap. 4MFD

There are three wires coming from the motor to a plug mounted on the
fan body. Two of the wires are mounted to a fat pin: the white and
green. The third wire is connected to the skinny pin: black. This is
all the info I have on the motor/fan.

 

[Nirodac]

Is there a capacitor somewhere in the picture. The rating plate says it
should be 4mfd.
If I under stand your description of the wiring, two wires are connected
together (white and green) and go to one side of the plug, and the black
wire goes to the other side of the plug. In some countries, white is
neutral and green is ground, these wires would go to separate connectors on
a three prong plug. Green to a round connector and the white to a slightly
wider flat connector. The black would then go to a slightly narrower flat
connector. Back at the breaker panel the white and green wires would be
connected together (usually). What's confusing me is the capacitor, it
needs to be in the circuit somewhere, usually common to one of the power
rails, and connected to an individual wire in the motor.

Ray

 

[Jason]

I do not see a capacitor anywhere on the motor. The three wires are in
one common rubber casing that come directly out of the side of the
motor housing. The motor housing is a sealed, slightly finned (or
ribbed), aluminum case held together with four screws. There could be
a capacitor in there, I don't know. The three wires are connected to
three pins, not two. All three wires are insulated from one another at
the plug and though the rubber casing into the motor.The two larger
pins are on the ends of the white and green wires. The third smaller
pin is connected to the black wire. I am in the U.S.if this helps any.
The fan is millitary suplus or out of an aircraft I think. The three
pins are part of the male portion of what looks like a two piece
circular plug. The same type used in aviation in some aplication. A
quarter twist then pull apart kind. The plug size is the diameter of a
nickle.($.05)I hope this helps discribe the wiring situation a little
more clearly.

 

[Nirodac]

My guess is that a 4 mfd capacitor should be attached to two of the wires
and that two of the wires should be attached to the 117 volts AC.
One lead, is power only, one lead is capacitor only, and one lead is common
to the capacitor and the power rail. Taking a big guess here, the smaller
black wire is probably the capacitor only lead, the green and the white
would then go to the power rail (the other end of the capacitor would be
attached to either the white or the green lead). The capacitor is a special
AC capacitor and would be rated at several hundred volts. You can get them
at some appliance repair shops or motor repair shops.
Aircraft used to use 400Hz for the frequency of the power. This reduced the
size of coils, inductors, and motors.
Because the rating plate said 117 volts 60 cycle, you should be able to plug
it into a standard US outlet (once you figure out where the cap goes).
If your unsure about plugging it into 117 VAC, place a 60 or 100 watt
incandescent lamp in series with the motor, if the motor shorts out, the
lamp will glow brightly (full brightness), but nothing will be damaged in
the motor.

Ray

 

[JeffM]

I have a fan and motor...need help wiring it.
Nice pictures & basics here:
http://www.motorsanddrives.com/cowern/motorterms1.html

You have to figure out how to get the Start capacitor
in series with the Start winding for a boost on takeoff.
If the Run winding and the Start winding have a common return,
an ohmmeter with good resolution
should let you find this mid-point.