Installation manual

D9124 Operation & Installation Manual

Page 20

74-06799-000-D 2/96

CIRCUIT 1 C

SILENCE

DOWN

NORMAL

Signaling Circuit

Figure 10: D192 Bell Silence Switch

Indicating Circuit (24 VDC Horns, Strobes, Bells)

Description

The D192C Indicating Circuit Module supervises the wiring from the control/communicator

to remote alarm indicating devices like horns, strobes, and bells. Wiring is supervised for

open, shorted, or grounded circuit faults.

Signaling devices must comply with the following parameters:

• They must be polarized (DC)

• They must match the voltage rating of the alarm power supply (D9142)

• They must not exceed the current rating of the alarm power supply (D9142)

• Combined, they must not exceed 1.8 Amps on motherboard terminals 7 or 9.

Total output power for the D9124 System must not exceed four Amps:

The total

output power for Auxiliary power (terminal 5), and the 24 VDC indicating circuits (terminals

7 and 9) must not exceed four Amps. Exceeding four Amps will overload the D9142

Power Supply. See

Calculations for 24 VDC Devices

to determine total output

requirements.

Operation

During normal operation, the indicating circuit is supervised for incorrectly installed

devices, opens, shorts, and grounds. If any of these conditions are detected, the panel

indicates a trouble condition at the command center. You can program the panel to report

the condition to the central station.

When the panel detects an alarm, the alarm output circuit triggers the D192C to supply

circuit power from the power supply.

To provide supervision, install the 560Ω, 2 Watt EOL resistor (15-03130-005) beyond the

last indicating device. Two resistors are supplied in the literature package.

Silence Switch

The D192C has a toggle switch that is used to disable the fire alarm indicating devices

while you test the panel (see

Figure 10

). When this switch is toggled up in the SILENCE

(OFF) position, the D192C presents a short circuit to Point 7, causing a trouble response.