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186
SCS Series Manual —
P/N 15712:L 7/18/16
Ratings and Wiring Diagrams
HVAC Wiring Diagrams
Figure 5.78 EP Damper Control - HVAC Switch Group Type 12
Figure 5.78 depicts an EP damper in an HVAC system with the capability of
OPEN
and
CLOSED
control, switch group type 12. In the above
configuration, the CON
ON⁄OP
CM is activated and the CON
OFF⁄CL
CM is deactivated. The CON
ON⁄OP
CM controls normally closed contactor
for the pressure switch power line. When the CON
ON⁄OP
CM is activated, the normally closed contactor is opened. When the contactor opens,
power is cut from the pressure switch which allows airflow to open the damper. When the CON
ON⁄OP
CM is deactivated, the EMS is free to
control the damper. The EMS is currently being overridden by the CON
ON⁄OP
CM.
FRM-1
COM
N/O
Airflow
PRESSURE
SWITCH
SMOKE
DAMPER
OPEN
Power Source
Listed
24 VDC
Power Source
SLC Loop
FCM-1
CON
OFF/CL
CM
(deactivated)
DE
P-h12
A
-fs-2.
w
m
f
Power
Return
Pneumatic
Tubing
Energy
Management
System
1a listed
contactor
1b listed
contactor
CON
ON/OP
CM
(activated)
*If the SLC device
does not match the
one in this figure, refer
to the SLC manual
appendix, which
contains wiring
conversion charts for
type V and type H
modules.