Disconnection times, some clarification

[goasis]

Evening, just revising for 18th update course and wondered if someone can just clarify something. (I might just be confusing myself, too long staring at the BBB)
Reg 411.3.2.2 ii) does that also include luminaries?
I understand 411.3.4 applies. Do notes 1 & 2 of 411.4.4 mean that the use of an rcd negates the need for a specific disconnection time?

Ta all

 

[Richard Burns]

Evening, just revising for 18th update course and wondered if someone can just clarify something. (I might just be confusing myself, too long staring at the BBB)
Reg 411.3.2.2 ii) does that also include luminaries?
I understand 411.3.4 applies. Do notes 1 & 2 of 411.4.4 mean that the use of an rcd negates the need for a specific disconnection time?

Ta all

Yes 411.3.2.2 ii) includes circuits that supply luminaires.
Asking if a regulation about circuit disconnection time applies to light fittings is a bit like asking if the price of eggs includes fluffy bunny rabbits!

Correct, a circuit containing luminaries in a domestic premises must comply with 411.3.4

Notes 1 and 2 of 411.4.4 mean that the required characteristics of RCDs as specified in their product standards are such that at high fault currents to earth the RCD will trip in less than the minimum time specified for TN systems in table 41.1, therefore the circuit will disconnect fast enough if protected by an RCD.
This does not remove the requirement for the circuit to disconnect in the times specified, just that compliance with the times will be met by RCD protection, by nature of their operating characteristics.

 

[goasis]

Great, thank you, I just wanted to make sure I understood it correctly.