7,300 Watts supplied on a 2.5mm2 T&E.

I have been through this at length. Cable current ratings in BS7671 are for 24/7 use at the stated load. Once one does not do this the rating can be much higher, provided there is reasonable certainty that the current cannot be significantly more than the BS7671 value for long periods. Reduced ambient will give a higher rating even 24/7. Consider this, what is the rating of a copper cable 2.5mm2 at -270 degrees centigrade? Take an electric motor of 3kW. What is the wire size in the windings? Is it around 2.5mm2 or is it considerably less? Why is this satisfactory? Z may code this, but what is the correct coding? In the “magic book” this is probably a C2, but this is clearly not correct. The potential danger is reasonably considered by me to be zero. Say the cable gets to 100C due to running the heater for a few hours by accident. The potential danger is certainly not electrical, although a burn could result to a person. Even this is fairly unlikely as we rarely grip cables tightly to see how hot they are. I note that any EICR codes issued by an NICEIC registered contractor must (their regulation) be as in the “magic book”. Guess who does not understand BS7671 or Electricity. 3 guesses, any takers?

I have been through this at length. Cable current ratings in BS7671 are for 24/7 use at the stated load. Once one does not do this the rating can be much higher, provided there is reasonable certainty that the current cannot be significantly more than the BS7671 value for long periods. Reduced ambient will give a higher rating even 24/7. Consider this, what is the rating of a copper cable 2.5mm2 at -270 degrees centigrade? Take an electric motor of 3kW. What is the wire size in the windings? Is it around 2.5mm2 or is it considerably less? Why is this satisfactory? Z may code this, but what is the correct coding? In the “magic book” this is probably a C2, but this is clearly not correct. The potential danger is reasonably considered by me to be zero. Say the cable gets to 100C due to running the heater for a few hours by accident. The potential danger is certainly not electrical, although a burn could result to a person. Even this is fairly unlikely as we rarely grip cables tightly to see how hot they are. I note that any EICR codes issued by an NICEIC registered contractor must (their regulation) be as in the “magic book”. Guess who does not understand BS7671 or Electricity. 3 guesses, any takers?