Whilst not directed at the public supply network, could the situation set out in figure 44.1 in BS7671 2018 cause damage to equipment on a LV installation connected to a DNO supply?
Whilst not directed at the public supply network, could the situation set out in figure 44.1 in BS7671 2018 cause damage to equipment on a LV installation connected to a DNO supply?
That is a very interesting question. It looks like the common N or PEN will have a Voltage rise on it above true earth with whatever consequences. This may be serious if the substation Re is high. The regs. suggest that the common system is to link the high Voltage and Low Voltage earthing systems together. I suppose then that local earth electrodes come into their own at installations along with equipotential bonding.
There surely must be automated disconnection apparatus to disconnect if this fault occurs.
Whilst not directed at the public supply network, could the situation set out in figure 44.1 in BS7671 2018 cause damage to equipment on a LV installation connected to a DNO supply?
That is a very interesting question. It looks like the common N or PEN will have a Voltage rise on it above true earth with whatever consequences. This may be serious if the substation Re is high. The regs. suggest that the common system is to link the high Voltage and Low Voltage earthing systems together. I suppose then that local earth electrodes come into their own at installations along with equipotential bonding.
There surely must be automated disconnection apparatus to disconnect if this fault occurs.
