Single phase motor

[silentspark]

Can anyone point me in the direction of some wiring diagrams for single phase motors?

I've disconnected a motor, to be replaced, from a ventilation system. I marked the connections as i disconnected them and drew a diagram. But I'm worried when I receive the new motor the colours may be different from what was removed so wont know where they go?

 

[NMc]

Try this link

Single-Phase Electric Motor Characteristics & Applications

 

[Marvo]

Generally single phase motors come with the capacitor already wired so you just need to connect the live, neutral and earth. 9 times out of ten there's literature with the motor or a wiring diagram on the inside of the connection box lid. If all else fails don't be scared to phone the agents or suppliers for advice.

 

[silentspark]

Thanks for the advice. The motor i removed is part of a ventilation system in a boiler room in an office block.

There were two 3 core flexes going from the connection box, to a joint box. One flex I'm assuming is a L and switchwire, via a paddle switch in front of the fan, to bring the boilers on via the joint box, as the boilers are only wired to operate once the fan is on.

There were 6 wires coming from the motor into the terminal block, 2 neutrals, earth, and 3 other wires. 2 of the wires didn't have anything coming out the other side of the terminal block, what would these wires be for? Adding in a speed controller? When reconnecting the motor I'm worried that I may confuse the two unused wires with the L

Sorry if my explanation is a bit unclear.

 

[gerard]

You could always insulate the wires with connector blocks and turn on power without the motor connected. Check each circuit individually - actuate paddle switch to check live, etc, and piece it together like that. Once your satisfied your not putting a live on a control wire, for example, things should be ok

 

[silentspark]

You could always insulate the wires with connector blocks and turn on power without the motor connected. Check each circuit individually - actuate paddle switch to check live, etc, and piece it together like that. Once your satisfied your not putting a live on a control wire, for example, things should be ok

I think you've misunderstood me gerard. I know the wires coming into the connection box, but how will I determine them coming from the new motor once i receive it? Will they be marked? On the motor I removed, there were 2 red wires and 1 orange but only 1 of the reds was used and the other red and orange were into the unused connections?

 

[gerard]

I think you've misunderstood me gerard. I know the wires coming into the connection box, but how will I determine them coming from the new motor once i receive it? Will they be marked? On the motor I removed, there were 2 red wires and 1 orange but only 1 of the reds was used and the other red and orange were into the unused connections?

On the new motor they will be marked, you will know the live and neutral. Haven't seen those colors in a while. But you should have no such problem with your new motor.

 

[Marvo]

Without details of the motor it would be guesswork. The wires could be for a bi-metallic/thermistor on the windings, the motor could also be multiple speed with a split tapped winding, there's many possibilities. Giving the make and model number of the original motor might help.