Should Moho 240vAC and 12vDC share the same earth.

[68c]

I ask as while soldering a wire in the van, repair to A Class electric mirror, I noticed sparks when touching the iron tip to the positive feed to the switch. Turning off 12v at the Schaudt control panel made no difference.
I was on Electric Hook Up and using one of the van's internal 240v sockets.
Unplugged the EHU and ran an extension lead from the house for the soldering iron and all well.
The sparks were not huge or noisy so unsure if it was 12v or 240v.
Is it possible there are shared earths, is this normal and safe?

 

[Richard n Ann]

I ask as while soldering a wire in the van, repair to A Class electric mirror, I noticed sparks when touching the iron tip to the positive feed to the switch. Turning off 12v at the Schaudt control panel made no difference.
I was on Electric Hook Up and using one of the van's internal 240v sockets.
Unplugged the EHU and ran an extension lead from the house for the soldering iron and all well.
The sparks were not huge or noisy so unsure if it was 12v or 240v.
Is it possible there are shared earths, is this normal and safe?

Yes that's normal.

 

[Richard n Ann]

It's just the 12v being shorted to chassis/earth. I used to run the iron on the inverter or if it's the big iron I removed the earth wire in the plug. I've got a 12v iron now though so it's not a problem

 

[68c]

Thanks, makes sense. Window working OK now so can relax and stop worrying.