10a or 6a (lighting )

[ez2own]

Hi people would i be correct in saying that the minimum requirements for fixed lighting according to the osg is 10amp for type b breaker for 17th ??? or could you use 6 amp ??

any help most appreciated ....

 

[Deleted member 19807]

you can use either as long as the fittings, cables (incl derating) and zs are ok.

 

[GLENNSPARK]

right then....the way to determine this is firstly to add up all the wattages on any loads connected to this circuit then divide this by the nominal voltage...so for instance you can go...1100W/230V=4.78..which is the amps. So in this case a 6A MCB would be ok. It all depends on how many loads are connected and the rating of course.....
Hope this helps.
Glenn.

 

[ez2own]

you can use either as long as the fittings, cables (incl derating) and zs are ok.

Many thanks hifly just as i thought ,

 

[GLENNSPARK]

Cables have to be able to carry the current demand and as hifly....comply with disconnection times etc. one of The rare ocasions where you might want to choose a c type MCB is where you have inductives whic have high inrush currents...such as moters and non-incandescent lamps etc....

 

[ez2own]

right then....the way to determine this is firstly to add up all the wattages on any loads connected to this circuit then divide this by the nominal voltage...so for instance you can go...1100W/230V=4.78..which is the amps. So in this case a 6A MCB would be ok. It all depends on how many loads are connected and the rating of course.....
Hope this helps.
Glenn.

cool glennspark , thanks all wattages are bang on so 6 amp more than enough .

 

[i=p/u]

what if they using floursescent fittings , would you still use this quick method glen

right then....the way to determine this is firstly to add up all the wattages on any loads connected to this circuit then divide this by the nominal voltage...so for instance you can go...1100W/230V=4.78..which is the amps. So in this case a 6A MCB would be ok. It all depends on how many loads are connected and the rating of course.....
Hope this helps.
Glenn.

 

[GLENNSPARK]

as long as your either on or under the rating of the MCB then yes. The thing to remember though ez....is when you start going onto c and d type MCBs ....your Zs is a lot tighter with these types of overcurrent devices so it would be prudent to only use them where absolutely required otherwise your cutting down your chances of compying with disconnection times.........

 

[GLENNSPARK]

what if they using floursescent fittings , would you still use this quick method glen

no....

 

[trev]

Multiply current by 1.825 (if memory serves me correctly) if there are flourescents
If I've duffed that someone will shoot me down hehe. Good job I bought an OSG eh guys?

 

[johnboy6083]

the derating factor is 1.8, or more accurate figure that the manufacturer may provide. This allows for harmonics and inductance caused by the ballasts ect.

 

[GLENNSPARK]

Yep. page 96 app1 note 2 OSG.

 

[telectrix]

i always multiply by 2. only because i can do it in my head.

 

[GLENNSPARK]

i always multiply by 2. only because i can do it in my head.

I like that tel.....