April 24, 20197 yr 16 hours ago, Quentindp said: Great insight guys! I am installing 8Kw instant heater (Stiebel Eltron DHC8EL), which is rated at 8Kw@220V (or 8.7Kw@230V). If I calculate correctly, this means it will draw approx 26-27Amps. If I installed a 30A CB using 4mm wire inside a conduit across 10m distance, with an isolator switch within 1m of the heater, would this be sufficient? Your help would be greatly appreciated. Thanks Quentin 4mm2 can carry about 40A current so it should be fine.
April 24, 20197 yr On 2019/04/23 at 6:31 PM, Quentindp said: Great insight guys! I am installing 8Kw instant heater (Stiebel Eltron DHC8EL), which is rated at 8Kw@220V (or 8.7Kw@230V). If I calculate correctly, this means it will draw approx 26-27Amps. If I installed a 30A CB using 4mm wire inside a conduit across 10m distance, with an isolator switch within 1m of the heater, would this be sufficient? Your help would be greatly appreciated. Thanks Quentin 8000w at 220v is about 36A and 8700W is close to 40A, so a 30A breaker won't be sufficient , 40A breaker rather, 4mm cable should be fine but I'd prefer 6mm if it was my house.
April 25, 20197 yr Sean is correct, the load current will be closer to 37 A. 40 A circuit breaker should be sufficient for a resistive load A 4 mm2 cable will be undersized. A 6 mm2 copper cable could be suffiecent depending on the length of the cable. I attached a few tables to assist, please note there are other correction factors that also needs to be applied to these ratings. Abedare used to have a nice download for a book called Cable Facts and Figures, but since they were bought over by the Chines they have gone down sadly I attached it as brochure 653 brochures_653.pdf Edited April 25, 20197 yr by Jaws
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.