Hi, I am looking for some advice on wiring a single phase, 2 speed motor to an autotransformer 5 position speed controller.



I have this fan:
Helios SVS125B – Single phase, 2 speed
And an ATC1-1.5A, 5 position speed controller.

Wiring Diagrams:
Fan:

The motor side is already pre wired and the connector block is prewired to the fan max speed (the 3rd image in the diagram).

Note DS2/2 is a 2 speed switch.



Fan identification:


Fan controller:

It is an ATC1- 1.5 amp model

Wiring together:

Is it just as simple as leaving the fan wired at full speed and use the following from the controller like this?:
Speed controller – Fan
U2 (N) – N
U1 (L) - 1


Whats throwing me is that the speed controller mentions 3 wire control where the Aux is maintained live, wired to the motor capacitor and the wiring diagram for the 2 speed switch. How do I know if I need 2 or 3 wire control? If I do need 3 wire control. Where would the U1 and aux cables from the speed controller go to the fan?

For reference this is the wiring diagram for a 5 speed auto transformer that is specifically designed for the fan I have:


Which would leave me to believe I just need 2 wire control?... confusing

 

Understand that your FAN has only a two wire hookup! The green wire is strictly a safety connection and is not part of the operation of the fan. So the very last drawing of post #1 is what you would use,
And CERTAINLY the illustrations do seem a bit confusing, or maybe a whole lot confusing. Or at least, rather ambiguous.

 

Thanks for the reply. I understand the green wire is the earth wire, however you can also have 3 wire motor control for 2 speed motors where there is a secondary winding for the slow speed. On some fans there needs to be a constant live wire to the capacitor as mention in the speed controller diagram, just not sure if my fan needs this ore not.

 

Thanks for the reply. I understand the green wire is the earth wire, however you can also have 3 wire motor control for 2 speed motors where there is a secondary winding for the slow speed. On some fans there needs to be a constant live wire to the capacitor as mention in the speed controller diagram, just not sure if my fan needs this ore not.

I am guessing that the circuit of your fan, as posted, is correct. Based on that circuit, you do not need any three wire connection.

 

Thanks for confirming. I'll keep it to 2 wire control and test it.