JOHNSON CONTROLS
8
FORM 160.43-NM4
ISSUE DATE: 11/12/2012
SECTION 1 - GENERAL
deadband settings verification at installation and re-
quire recalibration if installed elevation is 300 feet or
more above or below sea level. Refer to Section 3 Test-
ing and Adjustments.
LPCO controls 025 45742 are activated when the
bellows sensor responds to a pressure change. This
response actuates a single-pole double-throw snap-
action switch, converting the pressure signal into an
electrical signal.
At atmospheric pressure the switch contacts are made
between the Common and Normally Open terminals
and open between the Common and Normally Closed
terminals. As the pressure falls below the control CUT-
OUT setpoint the switch transfers to be made between
the Common and Normally Closed terminals and open
between the Common and Normally Open terminals.
As the pressure rises above the control CUTIN (CU-
TIN equals cutout plus deadband settings) the switch
transfers to be made between the Common and Nor-
mally Open terminals and open between the Common
and Normally Closed terminals. Refer to
Figure 1.
FIGURE 1 -
SWITCH CONTACTS
CUTOUT ON PRESSURE FALL
CUTIN ON PRESURE RISE
LD12521
