Thread: One for the sparkies

Originally Posted by RANDLOVER

Protection Coordination of Circuit Breakers - GSES


I suspect the scenario described above is pro'ly due to a poor earth, so the full short circuit current wasn't able to flow and rupture the fuse. Although in a 12 volt automotive system the battery may not be able to produce a fault current for long enough to operate a fuse that is only mildly overloaded, not so in a HV generator system that can produce massive currents.

People also confuse overload, over current and short circuit, from the above graph it can be seen that a mild overload can be permitted for up to 4 hours, but as the overload value increases the trip time shortens.

Which is all fine and dandy but from the auto perspective its fusing not a circuit breaker (although you can get them mostly we dont) if your cars battery cant blow a large automotive type fuse (lets say 100A) its probably due for replacement.

Originally Posted by Gav 110

Bloody new house bashers are still using it to save $5 per fit out

More to it than that, house bashers use it on lighting only, its not to save money on cable (marginal), its to save time in labour. Solid 1mm2 is far easier and quicker to fit off.

Originally Posted by Vern

More to it than that, house bashers use it on lighting only, its not to save money on cable (marginal), its to save time in labour. Solid 1mm2 is far easier and quicker to fit off.

I suppose they have to make a dollar or two where they can
Prices for wiring a new house are rediculous, last time I spoke to another contractor who does a lot of work for a couple of builders, the numbers he was throwing out weren’t great
He can only afford to send a tradesman out at testing and commissioning time
Apprentices do the rest
Sad state of affairs, having apprentices teaching apprentices
☹️

An apprentice is supposed to work under the supervision of his master or a time served tradesman.

Originally Posted by Bigbjorn

An apprentice is supposed to work under the supervision of his master or a time served tradesman.

The company’s doing houses in WA have exposed loopholes where they get away with getting apprentices looking after apprentices
No power so no isolation required
Wall chasing done by others, all they have to do is clip in cables
Terminations whilst still no power
Tradesman shows up when testing and commissioning

Originally Posted by Gav 110

I suppose they have to make a dollar or two where they can
Prices for wiring a new house are rediculous, last time I spoke to another contractor who does a lot of work for a couple of builders, the numbers he was throwing out weren’t great
He can only afford to send a tradesman out at testing and commissioning time
Apprentices do the rest
Sad state of affairs, having apprentices teaching apprentices
☹️

#1 Son was a domestic sparky apprentice early on in life... ended up working ( as app.) for a House Basher, and did 90% of the actual work. When HB employed another tradesman, #1 was nominally his "supervisor" for job direction / decisions !.

There is a reason I quietly check the work of any sparky in my house...

Originally Posted by scarry

Watts=Volts X Amps.

It doesn't relate to wire sizes.Wire sizes relate to Amps,or current.

There are charts and rules to work out wire sizes,depending on voltages,where the cables are run,etc,etc.

I am no sparkie,but i think that is correct.

Now where is Homestar when he is needed

Where indeed? Possibly playing trains somewhere. Or even gardening? Or even Plane Spotting at some airshow?

Originally Posted by 4bee

Where indeed? Possibly playing trains somewhere. Or even gardening? Or even Plane Spotting at some airshow?

Or sorting a genset out somewhere,or off in the new camper.