Instruction Manual

Electrical Specifications Electrical Specifications
74 NFS-640 Installation Manual P/N 51332:B2 07/27/2004
Signaling Line Circuit (SLC)
Notification Appliance Circuits & Releasing Circuits
Output Relays
Output relays for Alarm, Trouble, Supervisory, and Security are available on power supply
terminals TB8, TB9, TB10, and TB11 respectively.
Contact ratings: 2.0 A @ 30 VDC (resistive)
Four-wire Smoke Detector Power
Control Panel terminals TB7 RESET (+) and (–) supply filtered, low-noise power for four-wire
smoke detectors. Specifications are:
• Nominal voltage: 24 VDC
• Maximum rated current: 1.25 A DC
• Maximum ripple voltage: 176 mVrms
Refer to the Device Compatibility Document for compatible 24 VDC detectors.
Item Value
Voltage 24 VDC nominal, 27.6 VDC maximum
Maximum length 12,500 ft. (3810 m) per channel (NFPA Style 4) or 10,000 ft.
(3048 m) total loop or circuit length (NFPA Style 6 and 7)
Note: Refer to Appendix B.2 “Wire Requirements” for limitations.
Maximum current 400 mA peak, 200 mA average (max short circuit; circuit will shut
down until short is fixed)
Maximum resistance 50 ohms (supervised and power-limited)
Item Value
Max. wiring voltage
drop
2 VDC (except CMX which is 1.2 VDC)
Nominal operating
voltage
24 VDC
Current for all external
devices connected to
the control panel’s
power supply
6.0 A in alarm (3 A continuous)
Optional ACPS-2406 Total 6 A in alarm (5 A continuous)
Optional APS-6R Total 6 A in alarm (4 A continuous)
Maximum signaling
current/circuit per NAC
2.5 A
Note: Some devices have maximum draws less than this; refer to the
device’s documentation.
End-of-Line Resistors
(ELRs)
Control Panel NACs (TB3, TB4, TB5, TB6): 2.2K, 1/2 watt
ICM-4RK, ICE-4, VCM-4RK, VCE-4, and DCM-4RK: 4.7K,
1/2 watt (2 watts on 70 Vrms audio)
XP5-C, XP5-C, FCM-1 Modules: 47K, 1/2 watt
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