I have just been involved in a situation where temporary loss of neutral on a TNCS system caused thousands of pounds worth of damage. It seems this loss of neutral situation, either within or outside the installation, is occurring more frequently. SPDs are now commonly fitted but at DBS and generally with a Up in the order of 860v, so giving no protection on loss of neutral in a three-phase and neutral system. Cost benefit analysis across the national spectrum might not support a compulsion but is it time designers should be raising the issue with clients and at least offering a solution. On the other hand, is there a packaged solution?
If I ran my supply through an old but serviceable Voltage operated earth leakage circuit breaker with the E terminal connected to an earth rod and the F terminal connected to the supply neutral will that disconnect my supply if the neutral conductor rises in Voltage above say 20 Volts to true earth? They are rated to trip at 50 Volts max. but in practice they trip off at 20 to 50 Volts.
If I ran my supply through an old but serviceable Voltage operated earth leakage circuit breaker with the E terminal connected to an earth rod and the F terminal connected to the supply neutral will that disconnect my supply if the neutral conductor rises in Voltage above say 20 Volts to true earth? They are rated to trip at 50 Volts max. but in practice they trip off at 20 to 50 Volts.
