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NFS2-640/E Installation Manual —
P/N 52741:P2 7/10/14
Installation
Connecting the Power Cables
Connect external field wires to the power supply terminals TB10 RESET(+) and (–) to provide up
to 1.25 A of current for powering four-wire smoke detectors. See Figure 3.16 above. TB2 (on CPS-
24), TB10 and all 4 NACS share a maximum of 3.0 A in standby and 6.0 A in alarm.
24 VDC Non-resettable Power Circuit
The power supply provides one 24 VDC filtered,
power-limited, non-resettable power output, capable of up to 1.25 A. Use this circuit to power
devices that require low-noise 24 VDC power (such as annunciator model ACM-24AT or the
transmitter module TM-4).
Connect external field wires to power supply terminals TB10 NO)and(–) to provide up
to 1.25 A of non-resettable current for powering external devices such as annunciators. See
Figure 3.16 above. TB2 (on CPS-24), TB10 and all 4 NACS share a maximum of 3.0 A in standby
and 6.0 A in alarm.
3.7.6 Accessories DC Power Output Connections
Terminal TB2 supplies one (1) non-resettable, power-limited 24 VDC circuit and one non-
resettable, power-limited 5 VDC circuit available to power external devices. Applications that
require a 5V connection to the Accessories Output, such as an UZC-256, must be within 10 feet
(3.658 meters) of the power supply. The distance from the power supply to the accessory requiring
power must not extend past the length of the supplied cable, P/N 75657 (supplied with UZC-256),
which is 10 feet long. Do not splice or otherwise extend P/N 75657. Refer to section B.2, "Wire
Requirements" of this manual for all applications requiring a 24V connection. Connect wiring with
all power sources off.
• 24 VDC (nominal) @ 0.5 A max
• 5 VDC (nominal) @ 0.15 A max
Figure 3.17 Connecting to the Accessories Output TB2 on CPS-24/E
!
CAUTION:
During system reset, power remains at terminals TB10 NO)and(–).
A
M
P
S
24_TB
2
access.wmf
24V
- Blue Wire
COM
- Black Wire
5V
- Red Wire
COM
- Black Wire
