if you are going to fit DC isolators outside in the rain, in the middle of 'sunny' Dartmoor, it really helps not to use indoor grade copex fittings. There was even a puddle on the terminal and about 5mm of water in the bottom of the switch, as they hadn't even drilled drainage holes, or earthed the SWA armour on the AC switch, which also had a gap in the cover becuase it was screwed to a wonky wall. Needless to say the switch is definetly not quite right anymore......