What is the role of the Delay Relay?


We are finishing the Power module, following these instructions:

According to the instructions, it should be programmed into “Mode 10 and Timer 1 to 20 seconds”.
And according to the documentation of the relay itself, in this mode, it should kick-in when a signal is received on CH1 and turn off when the timer goes off.

Looking at the wiring on this picture, it seems that the power will be on whatever the switch position is. In one position, we are always connected to the line (from 1A to 2A directly), in the other, we get the line through the relay (1A -> COM -> NO -> 3A -> 2A) if we have a consistent signal on CH1.

Is the system supposed to act as a security turning off the PFC when the brain stops emitting on CH1?
Can someone confirm or clarify?

Thanks for your help!


@wsnook has voiced concerns about the relays being written as NO. I will say that I have experienced a time where I unplugged the Arduino, and the PFC immediately turned on all of the actuators on high. I tried to replicate this again but was unable, I’m not sure what exact combination of reboot I did to trigger this, very curious to get the thoughts of someone with more experience with electricity.


I would recommend replacing the onboard songle relay with a better quality outboard relay, ideally an SSR… Its simply a case of desoldering the relay and soldering links between the coil pads and the NO/NC tracks. The outboard relay coil connects to the NO/NC terrminal block, Com is no longer used.


@Webb.Peter, @atom, thank you for your feedback. I am still not sure to understand the role of the delay relay in the current setup though.

What will get into CH1? Why is the documentation saying to program the relay in “mode 10”?

We will surely perform more tests, but we re a bit anxious to burn our power module if we got the wiring completely wrong :stuck_out_tongue:

thank you for your help!