single phase motor

[onehot.t]

hi there is there anyone out there who can help me ,
iv,e brought a compressor with no eletric motor ,, iv,e had this 2 hp motor sitting on the bench so i want to use it on the compressor but dont know how to wire it ,,

the photo is of the wireing box on top of the motor

 

[roofman]

U1 should be live...U2 should be nuetral and earth to the motor casing. As with any electrical question always wise to cross check with another forum user when they pop along

 

[awemawson]

You'll have both ends of the 'run' winding, and both ends of the 'start' winding, and both ends of a capacitor to consider. Usually the start winding is in series with the capacitor, and the ends of the series chain are across the run winding, with the mains going across the run winding. Direction of rotation is set by swapping the ends of the start winding to reverse it's phasing relative to the start winding. Not clear from your close up which cable is which!

Originally there would have been a wiring diagram glued in the lid of the box - not still there by any chance?

 

[onehot.t]

found this in the lid ,
[

hope it helps as i dont want to burn the motor out

 

[awemawson]

So as I described, U1 U2 is mains in. Run winding is also connected across U1 U2. Start winding is between Z1 & Z2, and with capacitor is put across U1 U2. Extra start capacitor is in parallel with it but has the internal centrifugal switch in series.

Motor starts in direction set by the way the start winding is connected, and has both capacitors connected. As it speeds up the internal centrifugal switch opens and disconnects one capacitor.

 

[onehot.t]

so u1 is l ,, u2 is n , so where dose the earth or ground get connected to or is it just the case

 

[awemawson]

To the metalwork of the motor - there is usually a tapped hole in the connection box. Look at your photo, within the curve of the black wire is a mark on the case with the earth symbol (short & long bar) with what looks to be a terminal next to it. If indeed that terminal connects to the motor case then that's your earth connector.

 

[eil]

You seem to have the jumper plates missing that connects between Z1 and 02 and Z2 and U2 for one direction or Z1 and U2,O2 and Z2 for the opposite direction, make up some jump/fly leads to connect the poles up as shown in the diagram.

 

[onehot.t]

thanks guys ill be wireing it up later today ,, you were right about the jumpers just got to make a bracket to mount it on the compressor then wire up the switch