TYPE 4208 “S”
REMOTE STATION PANEL
INTRODUCTION
The “S” panel is used to transmit alarm and
trouble signals (via telephone lines) from the pro-
tected property to the remote station control unit
type 4293A or 4293AB. The “S” panel also super-
vises the lines.
CIRCUIT OPERATION (FIG. 22)
SUPERVISION CIRCUIT
Normd Operation
During normal operation, supervisory relay Kl is
energized. Current flows from K3B terminal 8 (-24
VDC), through the milliammeter (if used), K4B ter-
minal 6, contacts K4A (4&l), telephone line, the
remote station, telephone line, contacts K4B (8&
5),
K3A
terminal
4,
contacts
K2A (4&l), K3A
ter-
minal 1, K4A terminal 3, relay Kl (energizing Kl),
resistor R2, Kl terminal 8, diode Dl, Kl terminal
1, K2 terminal 2 to +24VDC at K4 terminal 2.
NOTE: Zener diode D2 is used to regulate volt-
age surges. The Zener breaks down at -24V so that
excess voltage doesn’t get to the remote station.
Trouble Condition
If an open occurs in the supervised circuit (in-
cluding the remote station), supervisory relay Kl
de-energizes and its contacts transfer.
Current
flows from K3B terminal 8 (-24VDC), through
contacts Kl A (6&4), the REMOTE TROUBLE
lamp (illuminating the lamp) and the buzzer
(sounding the buzzer) to +24VDC at Kl terminal
1.
The buzzer can be silenced by placing the NOR-
MAL/SILENCE switch on the “S” panel in the SI-
LENCE position (the REMOTE TROUBLE lamp
remains illuminated).
When the trouble is repaired, supervisory relay
Kl energizes, its contacts transfer, the REMOTE
TROUBLE lamp goes out and the buzzer sounds
(“ring-back”).
The buzzer can be silenced by returning the
NORMAL/SILENCE switch to the NORMAL posi-
tion.
POWER FAILURE CIRCUIT
Normal Operation
During normal operation power failure relay K3
is energized (120VAC is applied to K3 terminal 2
and neutral is applied to terminal 7.
Power Failure Condition
If AC power fails, relay K3 de-energizes and its
contacts transfer.
Simultaneously, a “trouble” signal (-24VDC) is
sent from terminal 5 on the
“A”
panel to K2 termi-
nal 7 on the “S” panel. This “trouble” signal (-24
VDC) energizes relay K2 and causes its contacts to
transfer.
When contacts K2A (l&4) transfer, the circuit
40
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