Saturday, Apr 18, 2009 at 10:39
Some confusion in terms seems to be arising here. Let me offer some clarification:
1. Any device which automatically controls or interrupts the current path is a referred to as Circuit Breaker. A Residual Current Device (RCD) is one of a group defined as an "Earth Leakage Circuit Breaker".
2. What is being referred to here by some as a "Circuit Breaker" is actually a "Overload Circuit Breaker" (OCB) which reacts to excessive current flow or short circuit.
3. There are other types of circuit breakers also but I won't cloud the issue with them.
4. An RCD and an OCB can be combined in the one enclosure and is then usually referred to a a "Combination Circuit Breaker". This is what is most usually being installed these days. If it trips it may not be readily apparent whether the trip was caused by either earth leakage or over-current until further investigated.
5. A manually operated switch is not classed as a circuit breaker. It is a "switch" or an "isolator".
So when we are referring to "the circuit breaker" we really need to say RCD or OCB to be clear about it.
In the original posting, Bekali said "it tripped the board at the caravan park". She did not say "circuit breaker". It could have been either an RCD or an OCB. The expression of "circuit breaker crept in later and seems to have confused things a bit. Later expression from Bekali made it clear that it was the Park RCD which tripped.
As Gerry points out, an RCD does not protect you from electric shock if you get your body between active and neutral, only if between active and earth. However most instances of electric shock are from active to earth. You will only get between the active and neutral if you are poking around inside the wiring or appliance where you should not be. It is alright for electricians to do this... they are expendable. LOL.
Cheers
Allan
FollowupID:
628002