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?
Nice idea, but any electronics is best avoided if possible especially zeners which are incredibly easy to damage. The protection circuits for them would require a lot of testing. Whilst the caps can't be set to a particular voltage their low cost, simplicity and reliability in a major fault condition is a better option. A precise trip voltage range is not required in such condition.
Nice idea, but any electronics is best avoided if possible especially zeners which are incredibly easy to damage. The protection circuits for them would require a lot of testing. Whilst the caps can't be set to a particular voltage their low cost, simplicity and reliability in a major fault condition is a better option. A precise trip voltage range is not required in such condition.
