I have found answers to all of my questions on your excellent forum until now. Anyhow, I have an ancient (1990?) spa with a Len Gordon FF-1000LTC controller and a 240v 2-speed pump. I want to add a remote switch to force the low-speed side of the pump to run without interfering with the normal operation of the spa.
I though it would be easy, but after opening the hood it wasn't obvious what should be done. I am not even sure how to experiment/troubleshoot safely with 240 since both conductors are hot.
The pump has terminals marked "HI" "LOW" and "COM" as does the controller panel. I can see from the controller schematic that COM is jumpered from LINE 2 (I phase of the 240) while the LOW traces back through a maze of switches and clocks to LINE 1 (the other phase?).
So, COM appears to be one phase of the 240 which is always “hot” while the HI and LOW are the other phase and are switched on and off by the controller? If this is the case I should be able to place a switch between LINE 1 and LOW that when closed will fire up the pump without messing with any of the other functions of the controller?
One fear I have is that I have the pump running on low via the switch when a bather turns on the jets at the spa. This would be sending LINE 1 to HI and LOW concurrently. Would this cause anything to blow up?
Thanks for helping a newbie, and let me know if you need more information.