I have a large DC electromagnet and a switching panel. The switching panel switches the DC voltage to the electromagnet on and off. For 'on'220VDC is put across the magnet, for off dump resistors are put across the magnet and both sides are connected to the 0V rail.
I have to supply a transformer rectifier to give the DC voltage, but do not know if I should earth the secondary. If I earth the secondary and some one touches the OV rail could they get an electic shock? Should i earth the OV DC rail iteself?b