Operating Instructions

Siemens Building Technologies, Inc. 3-1
3
Internal Hardware Components
Chapter 3 describes the internal Fume Hood Monitor (FHM) hardware. Chapter 3 discusses
the following topics:
• Circuit Board
• Alarm rel
a
y definition and specification
• Alarm buzzer definition and specification
• FLN trunk definition and specification
• Operating and power specifications
• Wiring diagram
Circuit Board
The printed circuit board of the FHM (Figure 3-1) is the central processing area. The following
components are not visible once the FHM is installed:
• Airflow sensor hose connection
• Alarm relay (wire receptacle)
• Digital input (wire receptacle)
• Printed circuit board
• Alarm buzzer
• LAN trunk (wire receptacle)
• 24 Vac (wire receptacle)