ITT 801P5 Switch User Manual


 
Page 16 Installation and Operation Manual
Deadband
The deadband is the separation between the increasing set point
and the decreasing set point, as shown in Figure 8. The deadband
can be anywhere from 1% to 99% of Full-Scale Output (F.S.O.).
In the case above where the Smart-Switch
TM
is controlling a
pump, a wider deadband reduces the frequency at which the pump
cycles on and off.
Window Mode
This mode is useful when you want to maintain pressure within a
certain range, and want to be notified when pressure either goes
above or falls below that range. In Window Mode, the Smart-
Switch® starts out actuated, then deactuates when it reaches its
lower set-point (SP1d or SP2d). As pressure continues to
increase, the switch actuates again when it reaches the upper
set-point (SP1i or SP2i). This range between the lower and upper
set-points is the "window". When pressure decreases, the
sequence reverses, with a deadband of 1% of F.S.O. at each of the
set-points. See Figure 9.
In this mode, the Smart Switch
TM
might be wired to, say, an alarm
bell, which would sound if the pressure either rose above SP1i or
fell below SP1d.
Figure 9 Window Mode
WINDOW
UPPER BOUNDARY
(INCREASING SET POINT)
LOWER BOUNDARY
(DECREASING SET POINT)
NO = OPEN
NO = CLOSED
NO = CLOSED