Oven & hob on 13amp fused spur

Actually Mike it will carry 13A for ever, it may get rather warmer than one likes, but will not fail open circuit. After an hour or two it will get to something under 100degrees. It will not melt or anywhere near. The PVC will slowly lose the plasticiser, so the cable will become stiff, and at some point will be brittle enough to crack, but, it will take a long time. In your car cables carrying 15A for long periods are often 0.75mm2, the BS7671 ratings are very conservative, and ignore the time variable (which is important) completely. Calculate the actual power loss (Watts) and think about it very carefully. The temperature rating is about life, not failure. How long does a few watts take to boil a small cup of water? Similar problem...

Actually Mike it will carry 13A for ever, it may get rather warmer than one likes, but will not fail open circuit. After an hour or two it will get to something under 100degrees. It will not melt or anywhere near. The PVC will slowly lose the plasticiser, so the cable will become stiff, and at some point will be brittle enough to crack, but, it will take a long time. In your car cables carrying 15A for long periods are often 0.75mm2, the BS7671 ratings are very conservative, and ignore the time variable (which is important) completely. Calculate the actual power loss (Watts) and think about it very carefully. The temperature rating is about life, not failure. How long does a few watts take to boil a small cup of water? Similar problem...