OPERATION

The Delta Controls Model 709 provides switch action at a selected elevation of a varying liquid level. The unit is located on top of the vessel with the primary element extending down into the vessel. The float rides on the surface of the liquid and is carried up and down as the liquid level varies. The attractor is coupled to the float by the float rod and also moves up and down as the level varies. The attractor is located inside of the barrier tube and is in contact with the process fluid. The switching stations are located on the outside of the tube and are isolated from the process fluid. Each station contains a magnet which is magnetically attracted to magnetic materials such as the attractor. The magnet is pulled in against the barrier tube as the attractor rises to the position of the magnet. The magnet is connected to an output dry contact switch which operates as the magnet is pulled in against the barrier tube. From 1 to 4 separate SPDT switches are simultaneously operated. The guide is always located just above the float. This improves reliability by helping to prevent rod bending, binding, and "hangups".

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Go to Delta Controls Float and Displacer Switches

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