- 28 Oct 2015
- Reaction score
A radial circuit can be thought of as just that - spur-on-spur-on-spur. As long as the circuit breaker is rated correctly, the 2.5 can never be overloaded.So my dummy question - how come it's ok to have the single radial cable just daisy chaining loads of sockets? I must be missing something, as that feels to my tiny brain, a bit like a spur?
Radials have lower current ratings than equivalent rings. What rating you use (say, 20A or 16A) is partly governed by the loop impedance - essentially the resistance of the wiring that will limit fault current. You want a low enough ‘resistance’ to ensure about 5 X the rating of the breaker to flow for a typical set-up.
For example, a 20A B breaker would require about 100A to flow to disconnect reliably. A loop impedance tester will check this is possible.