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160
SCS Series Manual —
P/N 15712:L 7/18/16
Ratings and Wiring Diagrams
HVAC Wiring Diagrams
Figure 5.51 Fan Control - HVAC Switch Group Type 14
Figure 5.51 depicts a fan in an HVAC system with the capability of
ON
and
OFF
control and verification of the
ON
state, switch group type 14.
In the above configuration, the CON
ON⁄OP
CM is deactivated and the CON
OFF⁄CL
CM is deactivated. These two control modules are always
in the opposite state when the smoke control system is in operation and are always deactivated during normal operation. The CON
ON⁄OP
CM
is wired in parallel with the EMS; when wired in parallel with the EMS the CM must be a relay module. When the CON
ON⁄OP
CM and the
CON
OFF⁄CL
CM are deactivated, the EMS is free to control the fan. In this case the EMS is
OFF
, so no power is being supplied to the fan.
When no power is supplied to the fan, the fan is
OFF
and the sail switch is
CLOSED
, indicating no airflow in the duct. The VER
ON⁄OP
MM
monitors the
OPEN
position of the sail switch, which would indicate when the fan is
ON
. In this case the VER
ON⁄OP
MM is deactivated
because the fan is
OFF
due to the EMS. When the CON
ON⁄OP
CM is activated for smoke control, the CON
ON⁄OP
CM overrides whatever state
the EMS is in and closes the normally open contactor, thus supplying power to the fan and turning it
ON
. When the CON
OFF⁄CL
CM is acti-
vated for smoke control, the CON
OFF⁄CL
CM opens the normally closed contactor and turns the fan
OFF
, overriding whatever state the EMS is
in.
Type 15 is used for
ON
and
OFF
control and verification of the
ON
and
OFF
state. Since it is possible to determine both
ON
and
OFF
verification
from switch group type 13 or switch group type 14, switch group type 15 would only be necessary for redundancy in verifying the state of
the fan. For example, if switch group type 13 is used instead of switch group type 14, the
OFF
state of the fan would be verified when the
monitor module is activated and the
ON
state of the fan would be verified when the monitor module is deactivated. Utilizing switch group
types 13 or 14 also saves the use of an additional monitor module. Switch group type 15 would use two monitor modules to provide the same
verification as types 13 or 14.
Power Source
1a listed
contact
Service
Disconnect
Switch
ELR-47K
(use 3.9K listed ELR with FZM-1)
Listed
Sail
Switch
N/O
COM
N/C
Power Return
Listed
24 VDC
Power Source
VER
ON/OP
MM
(deactivated)
fa
n-
h1
4-
fs-
2
.w
m
f
SLC Loop
FAN OFF
FMM-1
CON
ON/OP
CM
(deactivated)
FCM-1
CON
OFF/CL
CM
(deactivated)
Listed
24 VDC
Power Source
1b listed
contact
FRM-1
COM
N/O.
Energy Management System
*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.