Solid state relay for ON/OFF VFD

Hi guys,

I am thinking of using this solid state relay to control the motor ON/OFF signal of the Chinese VFD. Also maybe to control the Enable on each of the servos.

RS part 720-3956

I use 24Vdc for the control side, and I've tried this SSR with a simple LED and it switches on/off fine.

My question is: this SSR is rated at a maximum 100mA for the load side and I have no idea what the load would be on the ON/OFF contacts of the VDF or for that matter the servo Enable, I suspect very low. Do you think this would work?

Consequently I suppose these signal contacts would be isolated from any VDF/driver return surge on disconnect and a diode on the load side may not be necessary?

Thanks for your advice.

Edward

Attachment 22751

It's overkill but should work, the VFD should provide it's own trigger voltage and with that all you really need is some basic support components and a suitable transistor.
The maths and technology is very simple and the parts would probably cost pennies online, or less than a fiver from Maplin.

- Nick

Thanks Nick,

This relay is quite cheap, around £6 and would just be connected straight to one of the opto outputs of my controller (they can drive up to 80V). I only chose it because it goes with my 24V limits circuit.

Edward

If you have a common zero voltage reference it will work.