« on: 29/04/2021 15:21:50 »
and the rest of the bridge isn't connected.The rest of the bridge will be earthed and you should be able to see from my circuit diagram that I have connected the earth to all the heating circuits at the tower anchorages.
So the rest of the bridge is indeed connected via the earth and that's worth remembering because the power supplies and power lines at the deck anchorages must be kept isolated from the earth for the heating circuits to work properly and for safety reasons. One can't afford to ignore the risk for someone at the deck to touch a power line and touch the bridge earth otherwise the heating voltage may decide it is easier to go through the person than through the cables! Recognising that risk is why I have designed this safety switch which will cut the power if there is any imbalance in the 2 voltages dropped over each of the strand pair which carry the heating current.