I have mp2 gx 5000/48 with arduino connected to mp2 on usb.
The arduino drops connection when any 230v coil relay (omron my4 / small 2 pole contactor ect)which is connected on ac2 out is activated / deactivated, tried various relays / contactors with same result.
Tried separately powering arduino to see if it was mp2gx usb power dropping, but same result.
Only work around so far to work is rc snubber circuit on relay coil.
Anyone had similar or why such a small coil activation/ deactivation should cause this issue.
How is the relay triggered? Is it triggered by the arduino from one of the GPIOs? Does the relay coil have a flywheel diode across it? The flywheel diode queches the reverse EMF from the relay coil. If that is missing it will cause havoc.
You say you are using a 230v coil relay, how is it activated? From the arduino with a smaller relay thats switches the big 230v coil relay?
No flywheel diode. Relays are 230v ac coil.
Switching relay with manual override switch for testing.
So to make it clear:
230v coil relay is switched manually on acout 1 of multiplus
And arduino is powered from usb of multiplus
When relay is switched on, arduino drops connection?
If the above is the case, then it is a really strange issue
What is connected to the arduino and how?
Did you also try a powered usb hub in between mp and arduino? Because Mp usb output power is not that high
Relay is on ac2 out of mp2- on a sub db( feeding immersion/External socket/12v power supply).
Arduino is powered off mp2 usb.
Have tried a separate 5v power supply to Arduino- powered off house socket.
Arduino currently has a 8way relay board (3no. Relays control dc heater with 12v control circuit)- powered from 12v adaptor (fed from ac2 out) - have tested Arduino without being connected to relay board and same issue persists.