Outbuilding consumer unit

No, that thought is again ridiculous. You try it, you cannot do much with a garden tool to a catenary unless it is a powered hedge trimmer! This "thing" about T&E and sunlight is a red herring too, I have seen cables at least 50 years old in this position with only some minor surface roughness from UV damage. NOT a problem. Hituf is probably better from a UV perspective as it is Black, but it depends on the exact formulation of the sheath, black actually absorbs more UV than grey or white cable. You would be happy with SWA in the sun, why not T&E?


Now the outbuilding. Can the lighting circuit be overloaded, reasonably not? It is possible to overload (slightly excessive current presumably 32A in a 27A rating) but is it dangerous? Ok we calculate the maximum cable temperature rise as about 50 degrees, and choose the likely cable temperature, in winter probably about 10 degrees. So now explain the danger? In summer why would you use 2 off 3kW appliances for a significant period? I would say not and give it a C3, it requires improvement, and suggest fitting a 2 way CU, Whether an RCD is fitted too is a matter of choice, but there will be no discrimination with the indoor one. As Z says, possibly slightly safer in case of a failure.


Again there is a distinct overestimation of problems and choice of very unlikely worst cases.

No, that thought is again ridiculous. You try it, you cannot do much with a garden tool to a catenary unless it is a powered hedge trimmer! This "thing" about T&E and sunlight is a red herring too, I have seen cables at least 50 years old in this position with only some minor surface roughness from UV damage. NOT a problem. Hituf is probably better from a UV perspective as it is Black, but it depends on the exact formulation of the sheath, black actually absorbs more UV than grey or white cable. You would be happy with SWA in the sun, why not T&E?


Now the outbuilding. Can the lighting circuit be overloaded, reasonably not? It is possible to overload (slightly excessive current presumably 32A in a 27A rating) but is it dangerous? Ok we calculate the maximum cable temperature rise as about 50 degrees, and choose the likely cable temperature, in winter probably about 10 degrees. So now explain the danger? In summer why would you use 2 off 3kW appliances for a significant period? I would say not and give it a C3, it requires improvement, and suggest fitting a 2 way CU, Whether an RCD is fitted too is a matter of choice, but there will be no discrimination with the indoor one. As Z says, possibly slightly safer in case of a failure.


Again there is a distinct overestimation of problems and choice of very unlikely worst cases.