Section 5 audio phone circuit installation, 1 list of devices, 2 maximum number of devices – SilentKnight SK-FFT User Manual
Page 35: List of devices -1, Maximum number of devices -1, 1 list of devices 5.2 maximum number of devices
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5-1
Section 5
Audio Phone Circuit Installation
5.1 List of Devices
5.2 Maximum Number of Devices
The SK-FFT supports up to 48 zones. Each zone consists of one addressable
monitor module (SK-Minimon) and a minimum of one Fire Fighter Telephone Jack
(FFT-FPJ).
5.3 Wiring Requirements for the Audio Telephone
Circuit
The following information applies to the FFT-FPJ Fire Fighter Phone Jack.
5.3.1
Single Phone Jack Audio Circuit in Class B
Configuration
No special wire is required for the Audio Telephone Circuit. The wire can be
untwisted, unshielded, twisted or shielded as long as it meets the National Electric
code 760-51 requirements for power limited fire protective signaling cables.
54 Ohm maximum impedance - 12 to 18 AWG.
Twisted, shielded wire is recommended for maximum protection against EMI and AFI
emissions and susceptibility.
If using shielded cable, attach the shield to Grounding Stud below TB6 of the FFT.
Note: Do not ground shield on both ends.
Part Number
Description
FFT-FPJ
Fire Fighters Telephone Jack