|This is a four wire normally closed actuator.
This is a standard M30 threaded actuator and repalces any 4 wire normally closed actuator ever supplied by Robbens. It may look different to various other models supplied over the years but comes with its own thread adapter that will guarantee its fit.
It has a single cable with four wires, a live (brown) and neutral (Blue) to power it open and a grey and a black cable. The grey and black are either side of switch (like on a two port zone valve), connect the grey to a permenat live and the black then becomes a switch live for your boiler.