MCB breaker markings reset or thrown away

driverman · Aug 20, 2013

Hi Guys,
Hopefully a quick question.......Breakers are marked by the manufacture symbol if they can be reset / reused or thrown away after a fault current. Where in BGB or OSG can I find the symbols? I've been looking. I'm sure they are in there somewhere. Thanks

Darkwood · Aug 20, 2013

Not sure what you are on about but mcb's have a breaking capacity usually 6k domestic and 10k industrial if the fault current exceeds this then damage may be incurred to the mcb during a fault if th breaking capacity is higher than the fault current of the installation then simply resetting the device once the fault has been identified and cleared will be ok.

driverman · Aug 20, 2013

Thanks Darkwood, I'm rattling my grey matter, but i have seen the symbols whilst doing 2395. i may not be describing it clearly.
The symbols are something like... Ic with a symbol and In with a symbol Does that make sense?

Darkwood · Aug 20, 2013

The only symbols i see on mcb is the schematic diagram symbol for the mcb

[ElectriciansForums.net] MCB breaker markings reset or thrown away

Other universal symbols may be used or just simplified versions to show it breaks the line conductor.

shagbite · Aug 20, 2013

you're not confusing Icn & Ics with IΔn are you? because that refers to the sensitivity of your rcd.

Richard Burns · Aug 20, 2013

I think this picture shows the only reference to ICs and Icn on MCBs, might be considered a symbol.

gutterball · Aug 20, 2013

There's 2 numbers fo fault current 1 is the fault current that it will take and still be useable and the other its nackered. Ics serviceable icn nackered.

telectrix · Aug 20, 2013

but knackered is spelt with a K.

gutterball · Aug 20, 2013

Never was good at speelng

chrish_1977 · Aug 20, 2013

gutterball said:
There's 2 numbers fo fault current 1 is the fault current that it will take and still be useable and the other its nackered. Ics serviceable icn nackered.

That's how my teacher explained it Icn nackered, but he said Ics was shagged, haha

Darkwood · Aug 20, 2013

We were taught if the wires blobbed back its an overload and if its disappeared its a short-circuit.... now the joys of putting a 30amp BS3036 back in live on a fault :shout: ..... in the days your boss had one set of meters for the whole company so quicker to close yer eyes and pray