How to avoid light blackout

[Seabee]

I am having an old flat rewired with a twin RCD CSU but want the light circuits on separate RCBOs to prevent light bulb blow-out turning of the fridge. freezer etc. Should I get Type C or B RCBOs and which is best mfr. Box is a Wylex 6X6. tx

 

[davelerave]

b'6s would be more likely to trip than b10's -if an incandescent blows
c types will handle inrush/surges better but we only use them on commercial lighting

check the UK rules regarding freezers anyhow -preferable not to use rcd protection if rules allow

 

[Seabee]

Thanks for the reply - my understanding is that we no longer have the option. Either RCD/MCB or RCBO protection is required. I can se a lot of food going to waste if people insist on incandescent bulbs/lamps.

 

[davelerave]

ok

i'm not aware of any issues with b10's for domestic lighting


you're right to go with separate rcbo anyhow for lighting - combining lights and sockets not a great idea

 

[pennywise]

In all likely hood the RCD within the RCBO will pop it out when a lamp goes, regardless of whether its B or C type, in my experience anyway.

 

[davelerave]

In all likely hood the RCD within the RCBO will pop it out when a lamp goes, regardless of whether its B or C type, in my experience anyway.

why would that happen?

 

[pennywise]

Just in my experience have had it quite a few times in the past, when you get to the job and a lamps gone, the customer hasn't tried turning the RCD back on,The breaker hasn't gone it's just the RCD thats popped out. can happen with metal BC lamp holders, the filament touches down to earth when it goes and the RCD goes before the breaker.

 

[Seabee]

Thanks - so would a type B pop quicker than a Type C - if the mfr actually makes differnt ones rather than grading the production run?

 

[davelerave]

ya

you need lower fault loop impedance values generally for c type

that's a separate issue to the 'rcd' issue that pennywise referred to

 

[aptsys]

...can happen with metal BC lamp holders, the filament touches down to earth when it goes and the RCD goes before the breaker.

How would the filament touch something outside the glass envelope???

 

[Seabee]

It's a L/N short in the bulb that throws the MCB on a non-RCD board isn't it?

 

[pennywise]

How would the filament touch something outside the glass envelope???

woops you are quite correct, mind is a muddle today

 

[davelerave]

It's a L/N short in the bulb that throws the MCB on a non-RCD board isn't it?

ya magnetic trip usually

i'm not aware of the prob with incandescent and rcd?

but there can be other issues with rcd and lighting

 

[zone77]

on original question, you can install a dedicated socket that is`nt RCD protected for your fridge/freezer. make sure you label socket outlet ` freezer only`

 

[Seabee]

too late - kitchen rings installed!