Blue Sea 7718 Solenoid ML 12V

This switch is for applications where sustained control signals are needed to emulate a Normally Open relay.  This switch is way more efficient than a standard relay because it has a lower than usual current draw on the control circuit. 

Tech Tip There are only three wires in the wiring harness, one is the power supply to the switch, one is the power coming back from the switch to activate the relay, and one is a negative wire for the light in the switch.   If you mount the switch adjacent to other equipment you could take the positive and negative power supply from there and all you would need between the remote switch and the relay is a single wire.  This means you can use this relay to replace older ones that only have one or two wires.  There would be no rewiring to do.  The interesting thing about this switch is that they made it have a very low current draw. It only draws 13 mA continuous in the on position.  It briefly draws up to 7 amps when changing state.  This is quite a clever solution that makes high amperage remote switching available without lots of rewiring but with minimum power consumption.  Well done Blue Sea, this is clever engineering.