Something else not many people know ... what we refer to as a geyser combo breaker ... which has a green and a white lever ... can be used as an isolator ... in fact in many cases a double pole circuit breaker can also be used as an isolator/overcurrent protection device ... the only reason they make a geyser combo breaker is due to the cost.

In fact a good practice would be to use a 60 amp combo breaker /isolator where the cable from the meter which has an 80 amp council breaker is fed via 16 mm cable ... it would save you fitting a 60 amp circuit breaker with a 60 amp double pole isolator.

In my opinion ... it is not good practice to use an earth leakage as a main switch ... but it is not illegal ... if you want to screw your customer for constant call fees ... fit an earth leakage as a main switch ... eventually they will catch on and dump you as their sparkie.