MCB ratings 1

[stanleycrimper]

lighting circuits on a remote camp site are wired in 2.5mm and protected by 16A MCB's.is this correctly rated? some circuits only have 1 or 2 lights on it

 

[ScottyUK]

Possibly. The cable is thermally protected but you need to look at your earth loop impedance and the required disconnect time.


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If we learn from our mistakes I'm getting a great education!

 

[stanleycrimper]

im doing an inspection scotty,i thought 10A MCB would be suffice.the light switches are rated at 10A,so im thinkin about overcurrent protection to protect these?(highly unlikely due to little load tho)

 

[ScottyUK]

Well, you need to size the breaker to protect the installation so yes, if you have 10A switches then a 10A breaker is a reasonable choice. You still need to check disconnect time and earth loop impedance - if this is a physically long circuit then you may have problems with a 10A breaker, perhaps with a 6A too. One way around that is to use an RCBO.

If some of that makes little or no sense then please get some help from an electrician - saving a few pounds isn't worth someone getting hurt or killed. And yes, I know how tight funds are at some of the Scout sites and similar having worked on a couple in my younger days when I had time to spare (pre kids!).


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If we learn from our mistakes I'm getting a great education!

 

[FreddyNurk]

Is an RCBO (or RCD) not yet a requirement for lighting circuits under IEC?

 

[ScottyUK]

IEC - not as far as I know.

The British regulations require an RCD or RCBO in areas where there is an increased level of risk such as circuits in a bathroom, but it there is no universal requirement for lighting circuits to be protected by an RCD.

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If we learn from our mistakes I'm getting a great education!

 

[barsballe]

You also need to check for energy let through current and voltage drop.