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SCS Series Manual —
P/N 15712:L 7/18/16
187
HVAC Wiring Diagrams
Ratings and Wiring Diagrams
Figure 5.79 EP Damper Control - HVAC Switch Group Type 13
Figure 5.79 depicts an EP damper in an HVAC system with the capability of
OPEN
and
CLOSED
control and verification of the
CLOSED
state,
switch group type 13. 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 a 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.
When power is cut from the pressure switch, the damper opens. When the damper completely opens, the damper open limit switch is
CLOSED
and the damper closed limit switch is
OPEN
, indicating that the damper is in the
OPEN
position. The VER
OFF⁄CL
MM monitors the
CLOSED
position of the damper closed limit switch. In this case the VER
OFF⁄CL
MM is deactivated because the damper is
OPEN
.
FRM-1
COM
N/O
FMM-1
Airflow
PRESSURE
SWITCH
SMOKE
DAMPER
OPEN
Power Source
Listed
24 VDC
Power Source
SLC Loop
FCM-1
CON
OFF/CL
CM
(deactivated)
D
EP-
h1
3A
-f
s-2
.w
m
f
Power
Return
VER
OFF⁄CL
MM
(deactivated)
N/O
COM
Limit Switch
for closed
position
ELR-47K
(use 3.9K listed ELR with FZM-1)
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.