IET logo
 
IET
Decrease font size
Increase font size
Topic Title: Lighting circuit - overloaded ?
Topic Summary:
Created On: 15 November 2012 04:08 PM
Status: Post and Reply
Linear : Threading : Single : Branch
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 15 November 2012 04:08 PM
User is offline View Users Profile Print this message



loftyloo

Posts: 588
Joined: 23 May 2006

Hi, while working in a barn today was asked to look at some lights in an adjacent barn, on this circuit there are 3x 400w high bay lights and 4x twin 5ft fittings, when switched on, it lights for about 4 secs before tripping out, the lighting circuit tests out ok, but it's fed from a 10A type b rcbo, unsure how to work out the load on start up of the big lights, but would suspect the starting current is tripping the rcbo and they have been lucky to date,

It's wired in 1.5swa so would I get away with upgrading to a 16a type c rcbo, no problems with loop??? ( just a thought )
Any advice or info would be great





Lofty
 15 November 2012 06:43 PM
User is online View Users Profile Print this message



daveparry1

Posts: 5878
Joined: 04 July 2007

1.5mm SWA is rated at 18 amps so I reckon it'd be ok, or mabe a 10 amp type C mcb?

Dave.
 15 November 2012 06:55 PM
User is offline View Users Profile Print this message


Avatar for Legh.
Legh

Posts: 3435
Joined: 17 December 2004

Or a time delayed switch between the high bays and the LPMV lamps

Legh

-------------------------
Why do we need Vernier Calipers when we have container ships?

http://www.leghrichardson.co.uk

"Science has overcome time and space. Well, Harvey has overcome not only time and space - but any objections."
 15 November 2012 07:18 PM
User is offline View Users Profile Print this message


Avatar for weirdbeard.
weirdbeard

Posts: 1372
Joined: 26 September 2011

Hi lofty, I can confirm that in a recent installation of mine, there is a 16A type B 30mA RCBO supplied by a 100mA TD RCD which has worked fine for 4 or 5 months so far with 6X400W halides, I only fitted the RCBO as I didn't have a 16A MCB at the time, though I will be replacing the RCBO for an mcb as soon as I get around to it, to reduce the risk of unwanted tripping from the 30mA device, as it's too sensitive in my opinion for. edit to add: supplying discharge lighting

I originally tried a C 10 mcb and it tripped after about 20 seconds.

From the clampmeter, when they have settled, the lights run at about 13A

(Edited due to pressing the reply button before finishing message)

Edited: 15 November 2012 at 07:24 PM by weirdbeard
 15 November 2012 09:06 PM
User is offline View Users Profile Print this message



loftyloo

Posts: 588
Joined: 23 May 2006

Thanks... It one of them "can u have a quick look at "
Think I will grab a 16A type c rcbo



Lofty
 15 November 2012 09:19 PM
User is offline View Users Profile Print this message


Avatar for slittle.
slittle

Posts: 3372
Joined: 22 November 2007

I'm surprised it ever worked on a B10 device. If you look at most suppliers data for highbay fittings it will give you a good guide as to the rating they suggest.

We would always engineer for a C type and normally 16A.

I have seen it done with a 32A ring circuit and 13A sockets mounted at high level and the light fittings fitted with 13A plugs - different but seemed to work.


Stu
 15 November 2012 10:11 PM
User is offline View Users Profile Print this message



loftyloo

Posts: 588
Joined: 23 May 2006

i belive its been in there for about a year, does anyone know where i can get hold of a contactum 16A rcbo type C ?

not alot about, plenty of type B



lofty
Statistics

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2014 FuseTalk Inc. All rights reserved.