Figure 8-27.PIV position supervisory switch installation.
been opened two full turns the magnet is far
enough away from the reed switch to actuate it,
causing a supervisory signal at the control unit
and/or remote receiver.
Water level in sprinkler system reservoirs
must be maintained within certain limits. There
are usually automatic controls for maintaining the
desired water level. Water level supervisory
devices cause a supervisory signal when the water
level is not maintained between the desired high
and low limits.
A float-actuated level indicator (fig. 8-28) is
mounted outside on the wall of a tank with its float
and lever extended into the tank. The lever arm
pivots at the tank wall and rises or falls with the
water level. A switch or switches (one for high
level, one for low level) are actuated when the float
Figure 8-28.Water level switch (float actuated).