House Construction

[lopburi3]

Also 35 amps is not very much. In Japan I put a 50 amp breaker in. Here in the states I have a 200 amp main breaker.

Poster is using a 63 amp breaker.

Don't compare 115v countries to 230v for breaker size as at 230 volts you only need half the size breaker to provide the same amount of power. That is the advantage of higher voltage (lower amp levels and wire size needed).

I have never had a trip from lightning in the 27 years I have used GFI/RCCB type protection so suspect your electric service may have a problem (you sure something not getting wet - like an underground wire or outside light?) It sounds like you are in an upscale development so would ask them to have electric company check that neutral is grounded properly as a starter. I would not consider using underground service here as all electric cable I have seen is very substandard in insulator properties and PVC can not be counted on to last.

You can bypass the rccb and run a direct line to freezer. Just make very sure you have a good ground on the unit and a circuit breaker just big enough to cover it.

[Morgan]

What is the point of putting in a r.c.d over 35 mA. As 50 mA will kill you. Thats mA NOT AMPS. 1 mA = 1/1000 of an ampere. 5mA-10mA Throw off, painful sensation.

10mA-15mA=Muscular contraction, can't let go. 50mA and above Ventricular fibrilation and death. Thats the generally accepted effects of current passing through the human body.The r.c.d. should trip at not more than 40 ms.

[lopburi3]

What is the point of putting in a r.c.d over 35 mA. As 50 mA will kill you. Thats mA NOT AMPS. 1 mA = 1/1000 of an ampere. 5mA-10mA Throw off, painful sensation.

10mA-15mA=Muscular contraction, can't let go. 50mA and above Ventricular fibrilation and death. Thats the generally accepted effects of current passing through the human body.The r.c.d. should trip at not more than 40 ms.

50mA is not likely to kill you in an instant so even a high rated RCCD would be much better than none. I am sure most of us have tripped a 20 amp circuit breaker at some point and lived to tell.

But the reason is more fire and equipment protection than a normal breaker would provide. Nobody is recommending anything but about 30mA for house use that I recall.

[andy50]

you could use a 15 ma rcd,,breaker, they are used in school laboritories here in uk,on the test benches, but if used where they are exposed to a damp climate they trip out as they are too sensitive!(like me!)

[Emuu]

The whole issue of circuit breakers and circuits in general is based on power load.

The aim is to ensure that there is a weak link in the power chain that ensures the link fails before the rest of the chain.

If the wire is 1.0 mm copper, the maximum breaker of fuse on it should be 10 amp, otherwise the potential is for the wire's internal resistance to turn it into a heater under excessive load and the insulation catches fire and burns your house down.

Current is calculated by wattage divided by voltage.

Lighting circuits are normally low load, but not always. If they are low load, small (1.0 - 1.5 mm) wire can be used.

Power circuits are likely to run higher wattage appliances (a fry pan can be 2400 watts draining 10 amp of current on its own).

Convention simply divides all the lights in a house around enough circuits on light wire through 10 amp breakers, and does the same calculating the type of appliances typically expected in any area of the house to get the same effect, but on 2.5 mm wire and 20 amp breakers. If your kitchen has a fridge, a washing machine with heater and a microwave as well as normal toaser, frypan etc, you may need two circuits in it.

Special appliences like air conds, water heaters and/or stoves may need individual circuits and may even need 4 mm wire and a 32 amop breaker.

In a large establishment you also calculate the load losses on long wiring runs and upgrade cable sizes accordingly.

After calculating total loads, you may need to split across multiple phases to get as much power as you need from the street.

All of these matters are perfectly simple for a qualified electrician and totally impossible for anyone I've found doing electrical work in Thailand.

I would dearly love someone to show me a local who understands and applies these simple principals.