Before revision: Surge currents Surge currents are much lower in Category A locations than at Category B and C locations A building's wiring adds impedance that limits the surge current that reaches the loads when a voltage transient arrives at the service entrance (the point the supply company's wiring enters a property).
After revision: Surge currents A building's wiring adds impedance that limits the surge current that reaches the loads when a voltage transient arrives at the service entrance (the point the supply company's wiring enters a property).