- Reaction score
- 6,530
Putting on my student's tin hat, I'll give it a bash :
For bonding we are concerned about touch voltages and so the path must be comparable to the resistance of Cu and so we use resistivity ratios (>8). For use as CPC we use the adiabatic eqn and its k factors that include temp rise and thermal capacity of the materials. This gives a reduced steel requirement compared with bonding calcs and so SWA armour is often ok for CPC but not for bonding.
For bonding we are concerned about touch voltages and so the path must be comparable to the resistance of Cu and so we use resistivity ratios (>8). For use as CPC we use the adiabatic eqn and its k factors that include temp rise and thermal capacity of the materials. This gives a reduced steel requirement compared with bonding calcs and so SWA armour is often ok for CPC but not for bonding.