TYI’E 4208 “N”
SUPERVISED DC SIGNAL PANEL
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INTRODUCTION
The “N” panel controls two supervised circuits
transfer relay (Kl) that switches the panel to stand-
of alti signaling devices.
It has an automatic
by battery power if a power failure occurs.
CIRCUIT OPERATION (FIG. 6)
POWER ‘FAILURE CIRCUIT
and the alarm and supervision circuits.
Normal Operation
SUPERVISION CIRCUIT (“N” PANEL ONLY)
During normal operation, power failure relay K 1
is energized by -24VDC from RECT 1.
Normal Operation
Power Failure Condition
If a power failure occurs, power failure relay Kl
de-energizes and its .KlA and KlB contacts trans-
fer. When the Kl contacts transfer, standby bat,-
tery power (-24VDC) is applied to terminal 5 on
the “A” panel which causes the Sonalert to sound
and causes the COMMON TROUBLE lamp to illu-
minate: Current flows from terminal -BAT through
contacts KlA (4&l), diode D5, contacts KlB
(8&5) to “N” panel terminal 5 and also to “A”
panel terminal 5.
During normal operation, the alarm signaling
devices are supervised by current that flows from
terminal -24, through terminal 4, resistor Rl,
terminal G2+, to one side of the alarm signaling
devices, the EOL diode, the other side of the alarm
signaling devices, terminal G2-, fuse F4, super-
visory relay K3 (energizing relay K3), terminal
Gl+, to one side of the second circuit of alarm
signaling devices, the EOL diode, terminal Gl-,
fuse F3 and resistor R2 to terminal +24.
Trouble Condition
Standby battery power is also applied to the “N”
panel alarm and supervision circuits to provide for
normal operation of these circuits during an AC
power failure.
Current flows’from terminal -BAT through con-
tacts KlA (4&l), terminal -24VDC, to terminal 4
If an open occurs in an alarm signaling circuit,
supervisory relay K3 de-energizes and its contacts
transfer. A -24VDC potential is applied to terminal
5 in the “A” panel which causes the Sonalert to
sound and causes the COMMON TROUBLE lamp
to illuminate. Current flows from terminal -24VDC
through terminal 4, contacts K3A (l&3) and termi-
nal 5 to terminal5 in the “A” panel.
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