I have a large kitchen with the following appliances: – 8 hobs of 7.5 kW each – 8 ovens of 2.78 kW each These are each connected via 2 phases (230V). Everything comes together in the main cabinet and there they are distributed over the 3 phases of the grid (incoming = 3 x 230V). How can I calculate how heavy I should make my main fuse for this section?
Answer
Hi Roel,
If you divide everything nicely, you have between 26.1 and 28.1 KW per phase.
That gives currents from 113.6A to 122A. (I[A] = P[W] / U[V] )
If you then look at the available circuit breakers, this one of 125A is the one that is right for that. This circuit breaker is intended for cables of 35 mm².
In this calculation I have assumed that all appliances are switched on at the same time, and that there are no induction plates or microwave ovens.
| Line 1 | Line 2 | Line 3 | |
| Power (W) | 7500 | 7500 | 7500 |
| 7500 | 7500 | 7500 | |
| 7500 | 7500 | 2780 | |
| 2780 | 2780 | 2780 | |
| 2780 | 2780 | 2780 | |
| 2780 | |||
| Total power (W) | 28060 | 28060 | 26120 |
| Current (A) | 122 | 122 | 113.5652 |
Kind regards,
Luc.
Answered by
ir Luc Bosmans
Technology in the audiovisual sector
Industrial quay 170 B-1070 Brussels
http://www.erasmushogeschool.be/
.