Wednesday, March 09, 2005
French fuse box installation
After last week being cold and slow this week has been busy and very tiring. I've been too tired to blog even.
The
digger men came on Tuesday to cover the septic tank and soakaway. Well
digger boys actually, the pair of them didn't look old enough to drive,
but that is most probably just a reflection of my age. The two of them
did an excellent job after the inspector had been to check the tank and
soakaway were satisfactory. Once they had left I noticed a solitary
daffodil growing out of the flat sea of mud left behind. They must have
gone out of their way to leave just one plant standing.
Still plodding along wiring up the electics. I've moved onto the the two fuse boxes, one in each gite. The photo shows a French fuse box installation almost complete. The grey and black cables are the supplies to each circuit fed from a disjoncteur , overload/short circuit protection. They are the modules in the photo with black switches and are usually 10A, 16A; 20A, 32A etc. The disjoncteurs are arranged into three banks, each one additionallly protected by an interrupteur differential, an MCB with a 30mA RCD protection. Those are the larger three modules to the left of each bank and that's the trip that stops you getting killed if you stick your fingers in the sockets. We have three per fuse box, each 30mA protection, but with different sensitivities. One of them is designed, for example, to provide additional protection for a washing machine, or cooker, because of a potential DC component and/or water hazard.
I've got the added complication of our house having a 3 phase supply and, as in normal in France, a limit on your supply power. At the moment we are on 15 KVA, (15,000 watts). If you draw more juice than that the trip kicks in. You can increase your supply, but you pay a higher standing charge, and more per unit of electric. For most people choosing a lower rating (9 KVA is normally sufficient) is advantageous financially.
In our situation we need quite a bit of power for our house plus all the gites. The problem is we only need max power for short periods when we are full. The worse time is Easter when we are full and it's a bit chilly so people have the heating on. Summer is less of a problem. Three phase complicates matters further because if one phase exceeds one third of our maximum, it trips. Eg, 15 KVA gives us 75 amps in total or 25 amps per phase. If any phases draws more than 25 amps then the lights go out. Therefore it's crucial to 'balance' the phases. You can't just put one gite on one phase and another gite on a different phase. If a gite is unoccupied then it could cause an imbalance. What I have done is try to ensure that the ovens in different gites are spread amongst the phases, the 'kettle' kitchen sockets, the heating circuits, the lighting etc, all spread evenly, so if one gite is occupied it draws current from all three phases, and a second gite draws from all three phases, but different phases. It's complicated.
| 9:43:20 PM
French fuse box installation
