Operating Instructions

Internal Hardware Components
Siemens Building Technologies, Inc. 3-3
Digital input
The
digital input
(DI) is an auxiliary input that can be used for the input of DI Functions or for
custom-defined operations. The DI functions are: Sash height alarm, high face velocity alarm
disable, DI alarm point of OCC/UNOCC monitor. This is a dry contact input.
Specification
Recommended wire
20 AWG Twisted Shielded Pair (TSP)
Recommended max. wire length
100 ft. (30.5 m)
Max. input contact resistance
1000 Ω
Alarm buzzer
The
alarm buzzer
is an audible horn that sounds when the fume hood is operating outside the
normal conditions. When the sash status feature is enabled, the buzzer will pulse six times
per minute (1 second ON, 1 second OFF).
Specification
Alarm buzzer
85 dB @ 4 in. (10 cm), 2.3 KHz resonance
FLN trunk definition and specification
The
FLN trunk
is a set of contacts that can be used with appropriate wiring for a Floor Level
Network (FLN) connection. These contacts can be used only when the FHM is connected to
a field panel.
Specification
Recommended wire
24 AWG Twisted Shielded Pair (TSP), 12.5 pf/ft., 6 twists/ft.
minimum, 4000 ft. maximum
Operating and power specifications
Operating temperature
32° to 120°F(0° to 120°C)
Operating range
24 Vac, 50/60 Hz
Power consumption
2.5 VA, Class 2, at 24 Vac