House DB main switch

[Leecatt]

Does the main switch on a single phase DB have to be single pole, single pole and neutral or double pole, I ask this as there seem to be some confusion amongst a lot of local electrical CoC providers in Cape Town.

The db must be protected by a double pole disconnecting device that disconnects both the live and neutral.
If there is no integrated overload protection in the disconnecting device then a circuit breaker may be installed on the load side of the disconnecting device.
See SANS 10142-1:2009 section 6.9

[AndyD]

........What is that above the circuit breakers?

This would confuse the local sparkies. I assume this is a pic of a DB used in the USA not in SA.......

It was just a picture showing RCBO'S for the benefit of anyone uncertain what they are. t's not my handywork (my panels are far neater than that ) the DB shown is actually a UK 17th Edition compliant one, each socket and light circuit MCB has two wires because they generally use 32A ring circuits.

RCBO

[Dave A]

A residual-current circuit breaker with overload protection (RCBO) combines the functions of overcurrent protection and leakage detection.

With thanks to Wikipedia.

[AndyD]

Thanks Dave, forgot about wikipedia momentarily. Basically they're the size of an MCB, well at least the more recent versions are, the older ones are quite a bit taller than an MCB but same width. You fit one for each circuit being supplied from the DB and they provide earth leakage protection as well as overload protection to each individual circuit. The bonus is that an earth leakage fault just causes tripping of the guilty circuit and not the entire premises.

[Slow Blow]

I have learned something new now, I have been using RCD's for years and always thought that they were expensive ELCB's

[Mark_Spark]

Mind if i ask for a quote comparing CBs and these RCBOs?

[AndyD]

Well the good news is that RCBO's have come down in price and also now come in a form factor that's the same as an MCB which means they're not as tall as they were and can now directly replace an MCB without rearranging the other surrounding items to get them in.

The bad news is that I'm still importing mine as I need them from the UK because unbelievably the local wholesalers still aren't supplying them.

I also found out you can't get AFDD's here either yet