2: Fan And Damper Operation With The Scs-8; 3: Design Considerations; 4: Selecting Fan And Damper Capabilities - Honeywell NOTIFIER SCS Series Operation And Installation Manual

Preliminary SCS-8⁄SCE-8 Design Considerations
3.4.2 Fan and Damper Operation with the SCS-8
Control of a fan or a damper is achieved through use of a control module (CM).
Normally, control modules are used to activate and deactivate notification appli-
ances. When used with the SCS-8 they control the ON/OFF state of a fan or the
OPEN/CLOSED state of a damper. Monitoring the state of a fan or a damper is
accomplished through the use of a monitor module (MM). Normally, monitor
modules are used to monitor the state of a particular device. When used with the
SCS-8 they are used to monitor the ON/OFF state of a fan or the OPEN/CLOSED
state of a damper. Figure 3.3 shows a general layout of the components necessary
to control and monitor a fan.
The control and monitor modules are controlled by the FACP. The SCS-8 commu-
nicates with the FACP over the EIA-485 data line. Each SCS-8 must be set for a
specific address on the EIA-485 circuit, one that is different from all other device
addresses on the EIA-485 data line. There are 32 valid EIA-485 addresses in the
FACP, numbered 1-32, and each address provides 64 protocol points for the pur-
pose of communication with the FACP. The SCS-8 monitors and controls the con-
trol and monitor modules through the FACP by using the 64 points.
Each switch group on the SCS-8 is responsible for controlling and monitoring one
fan or damper. Four of the 64 available EIA-485 protocol points are used for this
purpose. For each of these four protocol points, an appropriate control or monitor
module must be present at the fan or damper.
Each switch group on an SCS⁄SCE consists of two LEDs for annunciation of fan or
damper status, one LED for annunciation of trouble conditions, and an ON/AUTO/OFF (OPEN/AUTO/CLOSED) three-position switch for
control of a fan or damper (through the control and monitor modules). The control of the control and monitor modules depends on the setting
of the three position switch.
If the switch is in the AUTO position and there is an alarm condition in the FACP, the control and monitor modules will function according
to the automatic programming in the FACP.
If the switch is in the ON (OPEN) position the SCS-8 sends a signal over the EIA-485 that overrides the automatic programming, ensuring
the ON⁄OPEN condition of the fan or damper.
If the switch is in the OFF (CLOSED) position, the SCS-8 sends a signal over the EIA-485 overriding the automatic programming, ensuring
the OFF⁄CLOSED position of the fan or damper.
3.4.3 Design Considerations
A primary concern in the design of a smoke control system is the type of system that will be used. Much thought should be given to the
building layout and occupancy. Some common questions include:
• What method of smoke control will be used to control the movement of smoke? (pressurization recommended)
• How many smoke control zones are there?
• Will existing HVAC equipment be used?
• Is there going to be pressurization in all non-fire zones or just surrounding zones?
• Are there stairwells and/or elevator shafts that need to be pressurized?
Once these questions are answered, the following information must be compiled prior to installation. Each step will be explained in detail on
the pages that follow.
1. Determine the number of fans and dampers that need to be controlled and monitored for smoke control.
2. Determine capabilities required for each fan and damper. Select a corresponding switch group type for each fan and damper.
3. Determine the switch group type configurations needed on the SCS/SCE.
a) Determine the dipswitch setting for the particular configurations.
b) Determine number of SCSs⁄SCEs required and an address for each.
c) Determine the individual point numbers used for each switch used.
The worksheets in Appendix B.4 on page 201 can help organize the information referenced above.
3.4.4 Selecting Fan and Damper Capabilities
After determining the number of fans and dampers required for the smoke control system, the designer must decide what capabilities each
fan and damper should have. The designer must determine which fans need on and/or off control, which dampers need opened and/or closed
control, which fans need verification of the on and/or off state, and which dampers need verification of the open and/or closed state.
SCS Series Manual — P/N 15712:L 7/18/16
Fan
MM
CM
SLC Loop
FACP/INA/NCA
Figure 3.3 Controlling and Monitoring of a Fan
Using Notifier Components
The SCS⁄SCE
EIA-485
Data Line
SCS-8
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