GFCI electrical panel

[Ian Gills]

My father-in-law explained that your whole system is 240, but for some strange reason you normally only take 2 phases to the house from the 3 apparently available on the power line. He was also surpised to see that there was no fuse between the panel and the main supply line. And was concerned that most houses appear to have 100 amp power lines feeding them, when I see on here and in my neighbor's house 200 amp panels.

In the UK, homes (of any size) are not allowed more than a 60 amp supply. Why, therefore, the concern on this board that a 100 amp panel in a home may not be enough? Granted we have twice the voltage, but 100 amps is as close to 120 as damn is near to swearing. I do not think I will update my 100 amp panel when finishing my basement. 100 amps is a lot of juice.

[Greg Fretwell]

The US minimum is 100a at 240v. 200a is becoming the standard. Big houses have 400a. They don't really take 2 of the 3 phases on the pole. We have the street distribution at 4100 to 13,000 volts and there is a transformer that takes one primary (plus a ground) and makes 240v centertapped for 2-3 homes. They bring 3 conductors to the service disconnect (2 hots and the centertap which is grounded/earthed). We get the 120 by using one hot and neutral (the centertap). You are right, the first overcurrent device is at the house. The primary of the transformer has a fuse but that only protects the transformer.