bs 1361 fuse

[i=p/u]

hi ho, i just replaced replaced 8 gu10 50W bulbs in room as were blown. there is 18 on the one circuit plus 3 mini strip lights under benches very likely 18W each, they were all working when i left and when she left room she switched all 3 switches on 1 go and she said the fuse had blown, would you say by her switchen all on one go would of blown the 5A 1361 fuse ?? i personaly think to many but when you add it up its under 5 A

18 x 50W = 900W / 230V = 3.9A
3 x 18W = 54W / 230V = 0.23A so roughly 4A all in, which is under 5A

any input guys before you all go your local niteclub and dance like your up a ladder and fallling

 

[i=p/u]

does 50W halogen gu10s use more than they state, think i heard or read somewhere before, or am i loosing it

 

[Knobhead]

Any incandescent lamp has an inrush current, hence a tired fuse goes POP

 

[i=p/u]

u aint just a pretty dude tony are you.... when i was working there today i found half pack of 5A fuses lying on top of cu .
would you say with the fuse keep blowing would destroy the lamps aswell in some way.

 

[GLENNSPARK]

Its like a b Versus a C or D type breaker innit.....slightly different charactaristics for inductives (motors, ballasts, etc)..........

 

[telectrix]

also, it's common for the fuse to blow when a lamp fails (more so with MCBs). an anti-surge (motor rated) fuse may cure your problem though.

 

[i=p/u]

well that sounds great telectrix would they fit in to the 1361fuse carrier or am i going to have to change..., i was thinking of changiung the fuse carrier to a 15A one

 

[telectrix]

bad idea.15A is a tad to high a rating for 1.5mm T/E . even worse if it's wired in 1.0mm. better would be to split the lighting into 2 5A circuits.

 

[Octopus]

Could you change the fuse carrier to a 15A, come of the CU in 2.5 to seperate enclosure and fit a 10A MCB?

 

[i=p/u]

isnt 1.5mm rated at 18-20A or something tel. too much work involved in splitting the lighting circuit. ive told them to change to energy efficent lighting (led) just weighing up mu options for monday morning

 

[i=p/u]

what about 15A fuse carrier to 13A fused spur then off too lighting??????

 

[telectrix]

10A fuse in the FCU, would be better. even better would be to replace the GU10 halogens with LEDs. ssimmples

 

[GLENNSPARK]

But remember a fuse is there to protect the circuit from damage so you still have the problem of an oversuze fuse at the origin of the circuit.......theres nothing to stop someone removing the fcu in future and just relying on the fuse at the board which at 15A is too much for 1mm............

 

[i=p/u]

1mm can take 16A if i remember right, the circuit is 1.5mm t&e. i aint as expierienced as i think i am so keep them comming sparkys.. where you get a 10A fuse tel, never seen one before or have i, naw i i havent hey

 

[telectrix]

good point. glenn. methinks I=P/U is looking for a quick fix. not a good idea. could try a 6A or a 10A MCB though , after a 15A fuse in the board.

 

[GLENNSPARK]

That will give the o/c protection he needs here......nice one tel..

 

[mogga]

HALERS lol BTW any scottish lads I hear the rep is "eyecandy" Might need to give her a wee call

 

[GLENNSPARK]

HALERS lol BTW any scottish lads I hear the rep is "eyecandy" Might need to give her a wee call

Did a rewire on this kitchen a few weeks ago....lovely bird she was....we had to go back to put a new central heating timer on for her earlier today....slurp...lol..

 

[i=p/u]

well i think change the lamps is easies option, what about that fuse that allows inrush currents tel, do they exsist that will fit in 1361 fuse carrier. if i changed to 6A or 10A mcb wouldn't that mean the zs would change and maybe not meet the requirements.

 

[platty1005]

i=p/u The steady current drawn by a lamp is when it is at its operating temperature which for incandescent lamps is around 2000 deg C the initial current draw at 25deg C can as as much as 5 -10 times the steady current. So switching all switches together gives a massive surge just like a motor starting current.
Put in the largest fuse permissible for the circuit cable and advise customer to switch the switches one at a time
If you uprate the fuse you need to confirm the Zs still meets the 0.4 disconnection time

 

[i=p/u]

is there any mcbsrcbos that would fit in the fuse carrier place

 

[i=p/u]

so you with me platty in chancging the 5A fuse carrier to 15A as it is on 1.5mm t&e, its a dr's surgery so they can take instructions and only the sockets are rcd protected

 

[GLENNSPARK]

Can you replace the cable with a 2.5 at the board then into an enclosure with a C type breaker in and then using the installed cable....out to the lamps?........

 

[i=p/u]

was thinking c type breaker too but why 2.5mm for 15A fuse. am i missing something reallly badly here.. do you think would still trip the blow 15A fuse, the type c breaker does sound the pigs ears

 

[platty1005]

1.5mm T&E ref method C (clipped direct )or buried in masonry has a max current 20A page 228 BS7671 Max Zs 1.70 at 70 deg so 1.7 x 0.8 = 1.36
If Zs is measured at less than 1.36 at furthest point on circuit and cable is installed Ref method C then 15 Fuse should be OK

559.6.1.6 max overcurrent device for normal lighting circuits 16A

 

[GLENNSPARK]

1.5mm T&E ref method C (clipped direct )or buried in masonry has a max current 20A page 228 BS7671 Max Zs 1.70 at 70 deg so 1.7 x 0.8 = 1.36
If Zs is measured at less than 1.36 at furthest point on circuit and cable is installed Ref method C then 15 Fuse should be OK

559.6.1.6 max overcurrent device for normal lighting circuits 16A

yep. got it platty (p) 282...thank you. :crazy:

 

[i=p/u]

where is the max zs readings for protective devices in the green 7671, if you can help

 

[malcolmsanford]

1.5mm T&E ref method C (clipped direct )or buried in masonry has a max current 20A page 228 BS7671 Max Zs 1.70 at 70 deg so 1.7 x 0.8 = 1.36
If Zs is measured at less than 1.36 at furthest point on circuit and cable is installed Ref method C then 15 Fuse should be OK

559.6.1.6 max overcurrent device for normal lighting circuits 16A

Think a GU10 Lamp holder might not come under that regulation

 

[malcolmsanford]

where is the max zs readings for protective devices in the green 7671, if you can help

Same as the Red in the tables

 

[i=p/u]

found it, just trying to get to grips with this book as first time looking at it. have you any valuable input to my original post malcom.