Fuse box Replacement

[Badwolf]

1 hour ago, Spitfire6 said:

Hi,

 never known anybody use wire diameter for conductors. Americans excluded.

2 x 2mm CSA is better than 1 x 4mm CSA. More so at AC.

Cheers,

Iain.

Iain - While I value your contribution to my ignorance, acronyms don't really help me much. Afraid that while N/M will understand you I'm afraid, not me.

[SpitFire6]

Hi,

 Sorry I could not find the  ² symbol so I typed Cross-Sectional Area.

Iain.

 

[AidanT]

1 hour ago, Spitfire6 said:

Hi,

 never known anybody use wire diameter for conductors. Americans excluded.

2 x 2mm CSA is better than 1 x 4mm CSA. More so at AC.

Cheers,

Iain.

Used a lot by electricians. Sorry I should have written it out in full

Aidan

[NonMember]

1 hour ago, Spitfire6 said:

never known anybody use wire diameter for conductors. Americans excluded.

Really? I've hardly ever come across anyone using cross-sectional-area. Mostly they use "AWG" or "SWG", both of which are specified and measured by diameter. Sure, the latest wiring standards documents might use CSA but real-world electricians convert them to gauge before buying.

Anyway, sorry to bring confusion into the discussion.

[SpitFire6]

I once met an electrician that thought 120mm² was 35mm². Never heard of that before.

 

[SpitFire6]

Hi,

 In my lifetime I have never met anyone (the electrician excluded) that talked about the diameter of a wire. Maybe why my mates tease me by calling me an electrician?

Cheers,

Iain.

PS. The only time my brain goes to AWG or SWG is if I'm buying solder, reading some old or American documents. Data cables?

 

Edited June 14, 2019 by Spitfire6
Added

[Badwolf]

Ok gentlemen. I get the point and thanks. So a complete turn (there and back soldered to the blades) of 2mm, should be sufficient and safe.

[Clive]

I have just completed my domestic electricians course today..... (passed)

IET/BS 7671 (ie THE standard to which electricians work) uses CSA when referencing cables. Never mentions diameters or AWG at all.

And every electrician uses 2.5 twin and earth (and so on) 

Maybe different in electronics?

[SpitFire6]

18 minutes ago, clive said:

I have just completed my electricians course today..... (passed)

IET/BS 7671 (ie THE standard to which electricians work) uses CSA when referencing cables. Never mentions diameters or AWG at all.

Maybe different in electronics?

Electronics; You just use the wire that fits or is calculated to the mm length & diameter?

I bought my RF/AF coils pre-wound. Never used the diameter for measurement.

Rewinders use diameter. Motor rewinders in the UK make a fortune!

 

Edited June 14, 2019 by Spitfire6
Added more

[Badwolf]

Clive - Congratulations.... but this is driving me nuts!!! Doing this to make my hobby safer, not to do my own degree. I just wanted to know what size wire to connect the back blades of the fuse box with, safely. 2mm, 3mm. 10mm... I don't care what size, diameter, cross section, square meterage... just what the h*ll do I go out and buy, steal, find in my tool box or dig out of a skip.   Maybe I'll just leave it alone!!!!!

[dougbgt6]

BW,

OK The question is what current are the big wires that supply the tops of the existing fuses rated at? Duplicate that and your safe. I suspect 27 amp, however 35 amp is available if your happier with that. Both of these are in my "car builder solutions" catalogue, 27 amp is 3mm and 35 amp  4.5mm. A 3metre length of either costs £2.50.

www.carbuildersolutions.com

Doug

 

[Badwolf]

Doug - Bless you.

[dougbgt6]

Thanks, I need a few more before I stand at the Pearly Gates. 

db

 

[Badwolf]

Take you time, we (I) need you

[Clive]

My "concern" is what is the total load that will be flowing though the wire? In all honesty I doubt more than 35A at any point, assuming headlights/heater/wipers etc etc all on. So I would be happy to use that, this info is based on the fact the cars originally had a 27Amp alternator that seemed to have been adequate. My own car has a 40Amp type alternator, along with a high pressure fuel pump and a few other extra bits and bobs and is never bothered.

[poppyman]

Surely everything will be fused anyway? So in my mind it should be perfect Badwolf.

Tony.

[Badwolf]

OK. Waiting for the cable etc. Then I will document it for good or bad.

[Badwolf]

Just noticed that the in-line fuse in my headlight relay kit is 40amp.  Is that not a little high for safety, and how would that fit into the new fuse box system?

I reckon that even in prolonged 'flash' mode 4 bulbs (2 x dip plus 2 x full) at 60w shouldn't pull more than 20amp.

[dougbgt6]

BW,

I bought the "Chinese loom" and it came with a 10 amp fuse. 

And you've just pointed out something that confused me. The head lights are either on low beam or high beam, EXCEPT when they're on low beam and you press flash, then you've got low and high. Flash comes from the purple fuse. Why?  Because I suspect the surge of current on one wire would be too much for the loom and those clever people at Triumph put in a feed from a separate source.

My flasher fuse is currently 25 amp, I think this may be too much, but it blew  a 10 and a 15. 

My "Chinese loom" has it's own fuse, in line. Originally I wired directly from the battery, but when I put the fuse box in I re-routed the wire to come off the top of the purple fuse which conveniently had a spare spade.  

Doug

 

[rlubikey]

4 minutes ago, dougbgt6 said:

The head lights are either on low beam or high beam, EXCEPT when they're on low beam and you press flash.

I think that's how they do it Doug. It means you don't break the current to the dip when you flash, which should (marginally) prolong the life of the bulbs and, because it's only momentary, you won't over heat the lamps. Well, that's the theory!

Cheers, Richard

[dougbgt6]

Richard,

yes, what I meant was the current is nominally 10 amps for low or high, but both on at once doubles the current, "The wires canny take it Captain!" Also I'm suspicious of the flasher stalk as I've blown 10 & 15 amp fuses using it.

Doug

[rlubikey]

I'm confused - it's the same (rated) current in each wire - the high beam wire takes its current, and the low beam takes its current. The ground wire takes the combined current - I seem to recall this is a slightly larger diameter. The cables from the battery to the switch take the combined current, but have much larger CSA (Cross Section Area) and therefore much higher rating.

Cheers, Richard

[SpitFire6]

Hi,

 Hope this answers the question? The flash is fired by the purple wire (Battery), so it works with the lights off.

Cheers,

Iain

[dougbgt6]

32 minutes ago, rlubikey said:

The cables from the battery to the switch take the combined current,

Normally you switch between low and high beam and the wire from the switch supplies one or the other, but not both at the same time. When you pull the flasher stalk low and high are on together, high beam flash getting a separate feed from the purple fuse. At first glance it looks very odd that low and high beam have no fuse, but high beam flash does. 

It would have been easy to wire it without the use of the purple fuse, but much heavier cable would be required. 

NM, explaination is also a good one.

Doug

[Badwolf]

Sorry everyone. I certainly appear to have stirred up things with this one!!

Doug- I have a similar, probably the same, Chinese headlight conversion kit. I just thought that I would check the size of the in-line fuse, to find that it was 40a, which I though was high. Now it turns out that yours was supplied with a 10a.. interesting. Is the manufacturer just putting in fuses that happen to be handy as there appears to be no consistency (not surprised on this sort of import) in construction.

As to the fuse box with the original high and low beam fuses, if these are now lower current due to the relay, should they be on the same value of fuses as before (probably,  in case the relay ever gets removed in the future) and should the single live feed to the relay unit, which takes the combined load of high and low beam, have its own (say 25a) fuse.