Bulletin No.177664-2
Rev. D
SureSite
®
Magnetic Liquid Level Indicator
Installation, Operation and Maintenance
Section 2: Switches
Operation
The SureSite Switch Module, available for use with the SureSite Magnetic Liquid Level Indicator, is a sealed assembly
containing a magnetically actuated “latching-reed” switch assembly. The reed switch is actuated by the movement of
the magnet contained in the SureSite float. The design of the reed switch permits the switch module to perform as
either a “normally open” or “normally closed” switch. When installed with the lead wires (or junction box) installed at
the top, the switch module is “normally open” and the reed switch will close with the rising fluid level in the tank;
remaining closed until a falling fluid level in the tank causes the float to drop below the indicating position, opening the
reed switch. When installed with the lead wires (or junction box) at the bottom, the switch module is “normally closed”
and the reed switch will open with the rising fluid level in the tank, and remain open until a falling fluid level in the tank
causes the float to drop below the indicating position, closing the reed switch. (See sketches below)
For electrical schematics of the switch module, please refer to the Wiring Diagrams, located on pages 5 and 6.
Installation
General: The SureSite switch module must be mounted 180° opposite the flag assembly of the SureSite Magnetic
Level Indicator and within its operating range. The installation of the switch module varies, depending on the switch
module housing and the type of SureSite Magnetic Level Indicator. The chart on the next page is intended to provide
an overview of the various switch modules and to indicate which diagram(s) should be referred to for installation
instructions.
- Normally Open Operation - - Normally Closed Operation -
Lead Wires and Junction Box Positioned at Top
Lead Wires and Junction Box Positioned at Bottom
Note: Do not use external magnet to test switch modules. Only use a Gems SureSite float assembly.
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