Advice on Installation

[Thomas Connolly]

Hi Folks,

If I'm extending a lighting circuit, (adding two pendants and an outside light) from an existing pendant but the board doesn't have any protection (an old BS3036 fuse board) What's the best way to add RCD protection?

The new cable for the switches can't buried more tore than 50mm deep and I don't want to whack an RCD FCU anywhere as they are quite bulky.

What would be the best course of action to take to install this circuit so it complies with the Regs?

Thanks,
T

 

[DPG]

I’ve asked the IET to clarify.
Might get an answer before the amendment?

Need a 'like' and an 'optimistic' combined icon for that one!

 

[sparksburnout]

The latching is an important point. Just the same as a no-volt release for motors.

Yeah but the DIN mounted 60898's in the CU are latched?

 

[sparksburnout]

The latching is an important point. Just the same as a no-volt release for motors.

Yeah but the DIN mounted 61008&9's in the CU are latched?

 

[SparkyChick]

Be interesting if any of them will commit what they have said to writing.

Wouldn't it just. Last time I checked I hadn't received an email.

The long and short of it is that NAPIT technical still consider RCD spurs and socket outlets to be acceptable but the guy I spoke to would not commit that to writing as 'it is just an interpretation of the regs'.

Here's where I have a problem with his interpretation. He quoted the part I've highlighted in red:-

531.3.6 RCDs for additional protection
The use of RCDs with a rated residual operating current not exceeding 30 mA is recognized as additional protection in compliance with Regulation 415.1. These RCDs shall be provided to comply with the requirements of Regulation 411.3.3.

RCDs for additional protection in AC installations shall comply with:
- BS EN 61008 series, or
- BS EN 61009 series, or
- BS EN 62423.

Where installed at the origin of a final circuit or a group of final circuits, an RCD with a rated residual current not exceeding 30 mA may provide fault protection and additional protection simultaneously.

NOTE: Consideration shall be given to the division of the installation (see Regulations 531.3.2 and 314.2).

And how he quoted it was that this specification of standards only applies when the device is to be installed at the origin. My interpretation of that segment means only that it can, in the case of high EFLI be used to provide fault protection when installed at the origin.

I did challenge him on this and basically said I thought he was stretching a bit, but that was his interpretation of the regs.

So, on the phone it's OK to continue using RCD spurs and sockets that are manufactured to BS 7288 but ask them for it in writing and it's a big fat NO!

 

[Bobster]

@SparkyChick

The section you've highlighted in red is precluding to using an RCD as fault protection in situations where the Ze or Ra of an installation means it would be impossible to meet disconnection times otherwise. I.e TT or generator fed installations.

Or that's how I would interpret it.

The section just above that is pretty cut and dry in what is and by means of absence what isn't, suitable for additional protection.