There's also a trade-off between conductor size and cost.
Indeed. The simplest (but most expensive) solution would simply to make the c.p.c.s (all the way back to the transformer) 5x the size of the line conductors - that way touch voltages remain below 50V even during a fault (or 10x and 25V if you prefer).
- Andy.
Thats just one of two other factors. Speed and transformer output drop also play a role in protection.
My point was by arranging the potential divider keeping touch voltages below 50V (or 25V) during faults you design out the need for any reliance at all on disconnecton times, or indeed voltage droop.
There's also a trade-off between conductor size and cost.
Indeed. The simplest (but most expensive) solution would simply to make the c.p.c.s (all the way back to the transformer) 5x the size of the line conductors - that way touch voltages remain below 50V even during a fault (or 10x and 25V if you prefer).
- Andy.
Thats just one of two other factors. Speed and transformer output drop also play a role in protection.
My point was by arranging the potential divider keeping touch voltages below 50V (or 25V) during faults you design out the need for any reliance at all on disconnecton times, or indeed voltage droop.
