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150
SCS Series Manual —
P/N 15712:L 7/18/16
Ratings and Wiring Diagrams
HVAC Wiring Diagrams
5.5 HVAC Wiring Diagrams
5.5.1 Fans
Figure 5.41 Fan Control - HVAC Switch Group Type 1
Figure 5.41 depicts a fan in an HVAC system with the capability of verifying the
OFF
state, switch group type 1. In the above configuration,
the EMS is deactivated. The EMS controls a normally closed contactor which switches power to the fan. When power is not being supplied
to the fan, the fan is
OFF
and the sail switch is
CLOSED
, indicating no airflow in the duct. The VER
OFF⁄CL
MM monitors the
CLOSED
position
of the sail switch, which would indicate when the fan is
OFF
. In this case the VER
OFF⁄CL
MM is activated because the fan is
OFF
and the sail
switch is
CLOSED
.
Power Source
Listed contact for
Energy
Management
System
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
OFF/CL
MM
(activated)
fa
n-
h1
-f
s
-2
.wmf
SLC Loop
FAN OFF
Energy Management System
FMM-1
*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.