"Peter Taylor" wrote
| > On a TT system you will need 30mA RCD protection on *all*
| > sockets, not just ground floor and garage.
| Owain, if you've got a copy of the On Site Guide, could you please
| have a look at Fig. 3a on pages 21/22. The middle diagram is my
| one, the one with the time-delayed 100mA RCD doubling as the main
| isolator. The 30mA RCD is fed via the 100mA, and the circuits it
| serves are labelled "note 2". Circuits fed directly from the
| 100mA are labelled "note 1".
| Note 1 says "circuits to lights, cooker, water heater, smoke alarms"
| Note 2 says "circuits to portable equipment outdoors and socket-outlets
| that may reasonable supply portable equipment outdoors (ground floor
| It doesn't mention upper floor sockets at all. Am I missing something?
| Where does it say *all* sockets.
I think they've missed something, not you.
Reg 471-08-06 requires *every* socket-outlet on a TT system to comply with
413-02-16 requires ZsIdeltan < 50V
413-02-20 for TT systems requires RAIa < 50V
In practice, you use a 30mA RCD unless you can prove your earth
electrode system is and will remain effective. Whitfield simply says that
all TT sockets require RCD.
| Also Clause 3.6.2 says "Where an RCD is fitted ...... in a TT system,
| the rated residual operating current should not be less than 100mA".
| Doesn't this mean that 30mA is too low????
I assume it's talking about whole-house RCDs which should be 100mA Type S
time-delay to allow discrimination against the 30mA Type G socket circuits.