Hi Graham I made the modification as suggested by the Eriba Emiga forum : Water water everywhere. It seems to work well with no arcing at the points
I have included said text.
Water water everywhere...
Sink Tap Switch Upgrade
Each time you lift the sink tap lever, a small micro-switch in the tap body operates and controls the 12 volt power to the pump motor in the water bottle under the sink.
The micro-switch contacts carry the entire current load and each time the switch opens or closes a small amount of electrical arcing happens, which will eventually cause the switch to fail. Although it is possible to dismantle the tap assembly and clean the contacts, it is a difficult and intricate task. Success is frequently short-lived and a new tap body costs around £30.
By incorporating a heavy duty relay into the circuit, the tap micro-switch can be relegated to the task of energizing the relay coil which only requires 50 or so milliAmps and will now last for ever. The current driving the pump is now carried by the relay, with contacts rated at 5 amps and designed for 100,000+ operations, and costs less than £3.
The relay Roger used is a miniature Double Pole Double Throw, but since only one pair of contacts is used you could buy the cheaper Single Pole model.
Apart from soldering the connecting wires to the relay, the remainder of the connections to the caravan wiring loom are made with either conventional screwed connectors; or push-fit joiners soldered or crimped to the wires.
Roger has provided a circuit diagram, showing the before and after wiring layouts, and an image of the relay strapped to the waste pipe.
This project does not (yet) include a step by step guide to the fitting and wiring process, so a degree of electrical knowledge is required, but is a very valuable idea for Eriba vans 5 or more years old.
pic_relay_diagram.png - Bild entfernt (keine Rechte)pic_relay_sink.jpg - Bild entfernt (keine Rechte)