Graham hi,
This certainly should not be happening!
When you refer to the trip switch are referring to the main circuit breaker?
For a 9.2KW supply this C/Bkr should be rated at 40 Amps. It may well be that you have a lower rated C/Bkr maybe 25A , 20A or 16A?
Typical Consumption Values:
Oven typically 2KW (no Hob we have a gas hob so can't quote) = 8A
Washing Machine (Cold Fill) up to 3KW = 13A
Immersion Heater 1.8KW = 7.8A
Electric Heaters (on 1.3 KW setting) = 6A each; (on 2KW setting = 8A each); (on max 3kW setting = 13A each)
Electric Kettle 2KW = 8A
Microwave 800W = 3.5A
Single Aircon Unit up to 2.5KW = 10A
Beware also of the fashionable ceiling mounted halogen downlighters, these are terribly inefficient for the amount of light they actually supply. In our kitchen we have just 6 of these (it's a small kitchen) but each is rated at 50W so just lighting the kitchen uses 300W...a single 80W striplight would provide more than the same amount of light for less than one third of the consumption.
It doesn't take long to rack up quite high consumption values especially during the Winter and as we all know electricity out here isn't cheap..
We used to be on a 4.3KW supply and frequently ran into the same problem you have; power management becomes very diificult. We upgraded to the 9.2KW tarriff and the Main Circuit Breaker was replaced as a part of the upgrade.
Finally, if you are in the Granada area or say 50kms around I can recommend a good leccy if you need one; he's the guy that attended to the upgrade of our system and he did all the new contract negotiating with Endesa on our behalf.
Hope this helps...
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