Electrical Spec for New House

[daveg]

Hi,
I'm a Brit living in Indonesia and we are having a house built here, but I know little or nothing
about electricity. Perhaps someone can help with some basic pointers.

In the next month or two, our contractor will start the wiring but I'm not sure what specifications to
set to ensure that the house doesn't burst into flames (as happens far too often here).

One problem is that safety standards are not as stringent as back home; also, finding a
knowledgeable electrician and the latest fittings is difficult.

If anybody could tell me in layman's terms, for example, whether each outlet should have it's own
cable (dedicated circuit) or is that just for appliances like ACs, microwaves etc.

Is there an easy way to stabilize the voltage, because the supply from the utility company
fluctuates?

Also, last week, the house we currently rent was struck by lightning, frying our TV, wireless modem and satellite TV decoder so we want to make sure not only that the wiring in our new home is safe, but also that our electrical appliances are protected.Lightning strikes seems to happen quite often here.

Would it be best to attach a lightning conductor to the new house? How difficult is it to do properly?
Or can we use surge providers on all the expensive electrical appliances? Is there such a thing as a
central surge provider so that we can install just one surge provider and then run all the appliances
off it?


Which brings me to the question of grounding. Why is it so important and what does it involve?
All appliances here only have two pins, no earth.
What are the negatives of only two pins and how to overcome them?

Thanks in advance for any answers you may be able to offer. And if you have any other tips they would be most welcome.

Dave

[wh666-666]

I can give you advice from some experience and a semi-professional background. Im surprised no-one has replied yet ...




Starting with lightning, if you are really in a prone hotspot, I wouldnt advise putting a conductor on your own house. Conductors are for tall buildings however all they do is minimise damage, not avoid it and the path the the earth needs to be as straight as possible for the least damage. What I would advise is putting a tall (hopefully 3 x the height of your house) and straight mast about 50-150 yards away from the house. Anchor in to the ground properly by bolting to a concrete base and secure with at least 4 strong guide cables around. If lighting is extremely close or on top of you, it should hit the mast and be earthed, well away from the house and not a fire or safety risk.





As for your voltage issue do a shopping search for an "AC Voltage Regulator". Raw AC (power coming in to the home) is considered dirty power, yours sound very dirty if it fluctuates so much to a noticable extent. Most of the time Voltage Regulators are bundled in uninterruptable power supplies with surge protection, but you can buy Voltage Regulators for the entire home ciircuit, fitted by an electrician, really recommended at least for circuits like your sockets.




As for your home circuit, below is commonly how its done in the UK and the best approach, however bear in mind it varies from country to country and the voltage there I imagine is 115v or something, half what we have.

In modern homes, a main box will have many different circuits coming out from it. Mine for example has over 10 slots for all the circuits around the house. Like the following:

- You should have one lighting circuit per floor of the house, so a two level house would have a downstairs and upstairs circuit. They can either be wired directly in to the ceiling rose or a junction box. The feed comes from the consumer unit, on to box 1, then box 1 to box 2, etc, until the circuit reaches the final junction box/ceiling rose. Over here we have maximum lengths of the circuit and maximum amount of wattage. Usually it is around 1200w, or twelve lights per circuit.
- Normal plug outlets for your appliances will be on a ring circuit. That is, power will come from the mains box, go to socket 1, socket 1 to socket 2, etc, then the last socket will loop back around to the mains box again completing a ring. Ideally to modern standards, the kitchen will have a ring circuit of its own since most of your 24/7 and power hungry appliances are in the kitchen. You should have a couple of ring circuits.
- One of the only appliances that needs it separate circuit is an electrical oven/hob combi. This will go on a circuit a bit like a ring, except it will terminate at the appliance/fused box and not loop back to the mains box.
- Other circuits like outdoor ones will be on their own separate circuit.

Check out the regs in your area for cabling. For instance on ring mains over in the UK, one would use a 2.5mm core cable and a 1.5mm or 1mm for the lighting circuit ....

Then some things that should be universal is watch out for cowboys taking cablings diagnally across walls or cabling above outlets. Cables should run horizontally and vertically and the outlets should have cable running from underneath. Having cables running above an outlet or diagnally is a bit of a fire risk.