We use a PLC to control a 220VDC supply (and a lot of amps)to an electromagnet. The PLC controls big contactors which when 'on' is selected, put the full 220VDC over the magnet. When off is selected the contactors switch in a dump resisitor and connect both sides of the magnet to the 0VDC rail.
Now it is this aspect which worries me. If someone unplugs the magnet when it is 'off', and touches the 0 Volt rail could they get a shock? At the moment I do not think the electrical techs ground the DC supply 0V rail. To me that means that 0V could be floating and still give a shock. The DC supply is provided by a transformer rectifier.
Does anyone have any ideas about this? Big electrical stuff is not really my area, but having seen the circuit diagram that the PLC is to control I got a bit worried.
Now it is this aspect which worries me. If someone unplugs the magnet when it is 'off', and touches the 0 Volt rail could they get a shock? At the moment I do not think the electrical techs ground the DC supply 0V rail. To me that means that 0V could be floating and still give a shock. The DC supply is provided by a transformer rectifier.
Does anyone have any ideas about this? Big electrical stuff is not really my area, but having seen the circuit diagram that the PLC is to control I got a bit worried.