SSR on expansion heater

[cosmowave]

I'd like to connect a SSR to the exp.heater3.
Can i directly wire the SSR to the expansion connector? Or should i use a driver between?
The SSR input is 3-24VDC.

Is the exp.heater3 output switching to ground?
If so, i think it is correct to connect the + of the SSR to the +3.3V on the Duet2 and the - of SSR to the exp.heater3?

Thanks in advance

[chrishamm]

@cosmowave Usually SSRs don't take much to drive them but it's best to check how much current it draws. Do you have the datasheet of that SSR?

Note that the expansion pins of the Duet 2 do not have any pull-up/pull-down resistors, so it would be a good idea to add that to your wiring.

[cosmowave]

@chrishamm It's a "A-senco SSR-500". The input is for 3-32VDC and it draws 6-20mA according to datasheet.
When i connect it to the expansion pin with 3.3V, i think it draws a bit more than 6mA.?

Thanks for the hint with the resistor.

[dc42]

@cosmowave if you are not already using the PS_ON output then I suggest you use that one instead.

[cosmowave]

@dc42 Thanks for your answer. That's a good idea... it was not in my mind.
Do i need also a pull up resistor with the PS_ON pin?

[dc42]

@cosmowave you don't need a pullup resistor anyway when driving a SSR.