[chbot] OT: Low profile RCB

[Volker Kuhlmann]

On Mon 14 Jul 2014 14:00:46 NZST +1200, Robin Gilks wrote:

> Something wrong with your RCD - maybe its an older style earth leakage
> sensor type. All they *SHOULD* do is compare live and neutral current and
> if they differ by more than the amount specified on the front then trip.

I doubt there is a fault with it. Merlin Gerin purchased new in about
2008.

Actually come to think about it, they trip with neutral-earth shorts as
well, which I regard as a good thing because it also indicates a wiring
fault somewhere. If that has changed with new RCDs I'd want a ground
fault interruptor too.

> My system has a 200mA trip on each of the 3 phases immediately after the
> main isolation switch.

Well that probably explains it. As per my previous post I have 30mA
types. From memory, I have never come across a recommendation of
anything but 30mA, or 10mA for more localised loads (e.g. single
appliance).

I would definitely not replace all the 30mA types with 200mA for the
sake of a few loads that don't really need an RCD - getting zapped with
200mA is a much bigger problem than with 30mA. Using 200mA types only
where the 30mA doesn't work might be sensible. I'll keep it in mind next
time a switchboard replacement is on the cards... Thanks for pointing it
out.

Volker

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.