Tecfluid VH35 AISI-316 - Manual (Page 2)

INTRODUCTION
The VH-35 is a mechanical flow switch with a paddle which is displaced by the force of the flowing liquid.
The movement of the paddle displaces a magnet which activates the reed switch.
INSTALLATION
Mount the flow switch in a horizontal pipe with the hanging paddle in a vertical position and perpendicular
to the flow direction. The shaft, on which the metal paddle hangs, should be positioned at the internal
diameter of the pipe. To achieve this position, the top of the threaded fitting should be at 24 mm (0.96
inch) from the internal diameter of the pipe.
NOTE: On special order the VH-35 can be supplied for mounting in a vertical pipe with rising flow
direction. In this case the paddle has a stop to avoid it falling, and the switching flow rate will be higher
than the version for a horizontal pipe.
The paddle should be free to move without touching the pipe. The flow switch will work with flow in either
direction in a horizontal pipe.
For the electrical installation, a multi-conductor cable should be used to obtain a good seal with the cable
gland. The connector is provided with a PG 9 cable gland, suitable for a 4.5 to 7 mm outside diameter
cable. Connect the reed switch as required. Terminal 3 of the connector is the common, terminal 2 is the
normally closed (N.C.) contact and terminal 1 is the normally open (N.O.) contact when there is no flow.
The fourth terminal is an earth connection which is connected to the body of the flow detector.
Make sure that the contact rating is not exceeded. If high loads are to be switched, use an auxiliary relay.
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