Noobie fitted a relay to my air horns today

[rustic]

Originally Posted by firebobby

I had a vision of Alex sat at his desk, studiously raking through volumes of "wire weekly", desperately searching for the information that uncle Rustic was demanding

If you know what you are doing, it's fairly basic stuff, I am installing an anchor winch to our boat, and the cable length could be as much as 7m each way, depending on the cable size, I have to calculate the voltage drop, and see if the voltage at the winch is enough to prevent it stalling, having a low voltage can be more damaging than having a high voltage, depending on the application.

(For example, an inverter will have to work harder for the same load, when the supply voltage is lower, as the current in will have to be much greater.
Motors, if on low voltage can stall, or burn out because they are not rotating fast enough, which can also affect the cooling effect.)

I will then compare the actual voltage drop to the calculated value, dependant on the load.

If you want things to be reliable, and not "just" work, then that is what you have to do.