SANS 10142 Lighting Question

[JesseDC]

Afternoon everyone, I need some help interpretating a extract from lighting from section 6:
6.14.1.2: Each identified group of single phase luminaries supplied from a multiphase supply that also feeds other luminaire's shall be controlled by a local multiphase disconnecting device
Note: The disonnecting device should disconnect all live conductors that feed the group of luminaires, including the neutral, in order that maintenance work can be carried out without switching off lights.

The way I see this is that each group of lighting supplied by a different phase must have a double pole disconnecting device, but I haven't seen this before, so maybe I'm interpretating it incorrectly

[Dylboy]

This one confuses me, struggling to make sense of it too.

Single phase lights that come from a 3 phase board must each circuit have a double pole isolator or a double pole CB?

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[GCE]

Hi

I have always understood this particular regulation to deal with a 3 phase supply with neutral ( multiphase) feeding for instance carpark lights where you take the 3 phase cable and loop from pole to pole and from the connection in the pole up to a single phase light head.
You would then put a Double pole or 4 pole isolator so that you only switch that pole off and can work without the neutral becoming live - Or install a 4 pole feeding that line.
Alternatively , if you feed a carpark kiosk and then from that kiosk you split off into different directions you would need to switch with D/pole or 4 pole to prevent switching the complete carpark off to avoid the neutral becoming live while working on one line of single phase feed.

In shopping center's or the bigger line shops they used to take a 3 phase supply into the trunking and the row of single phase fluorescents would be balanced across the phases in the row. If you worked on one fluorescent you would then take out half the shop or all the mall passage lights. Now they rather supply single phase circuits and feed a batch of 10 or so fittings on a single phase circuit.

Car park lights also tend to be smaller circuits at a time.

I understood that it had to do with the neutral becoming live when you disconnected a row of fittings.

That has been my take , not sure if I see it correctly. Also don't think it really applies much anymore becuase you tend to take from a D/Board with single phases circuits or a kiosk versus having a stubby joint box in the middle of the carpark and feeding in all directions.


6.14.1.2 Each identified group of single-phase luminaires supplied from a
multiphase supply that also feeds other luminaires, shall be controlled by a
local multiphase disconnecting device.
NOTE The disconnecting device should disconnect all live conductors that feed the
group of luminaires, including the neutral, in order that maintenance work can be carried
out without switching off all the lights.