TYPE 4208 “D”
LOCAL ENERGY AND SHUNT CONTROL PANEL
General
The “D” panel is used to control auxiliary muni-
cipal fire alarm boxes. It includes a “Drill” func-
tion that sounds the local alarm signals without
tripping the municipal box. This section is divided
into two parts: the first part explains “D” panel
operation when it is used with a local energy mas-
ter box ; the second part explains “D” panel opera-
tion when it is used with a shunt type municipal
box.
“D” PANEL AND LOCAL ENERGY MASTER BOX
INTRODUCTION
In a local energy type system, the lines between
the “D” panel and the municipal box are super-
vised. An open in these lines will cause a system
“trouble” condition.
In an alarm condition, current is increased to en-
ergize the municipal box. After the alarm condi-
tion is restored, the trouble signal will continue to
sound until the municipal box mechanism is reset.
NOTE: When a local energy box is used with a
“D” panel, the local energy box is connected be-
tween terminals 13 and 14. Contacts KlB and
K3A are not used.
CIRCUIT OPERATION (FIG. 7)
SUPERVISION CIRCUIT
When the K3B contacts transfer, -24VDC is app-
lied from contacts K3B (8&5) to “‘A” or “AX”
Normal Operation
panel terminal 5 which causes the COMMON
TROUBLE lamp to illuminate and causes the
During normal operation, -24VDC is applied to
terminal 12.
Current flows from terminal 12
through the fuse, the L.E.B. (between terminals 13
Sonalert to sound. Refer to “A” or “AX” panel
- Zone Trouble Condition for detailed circuit de-
scription.
and 14), resistor R 1, trouble relay K3 (energizing
the relay) to +24VDC at terminal 11. The L.E.B.
is not energized at this time because of the current
limiting effects of K3.
ALARM CIRCUIT
Alarm Condition
When an alarm is initiated within the 4208 sys-
Trouble Condition
tern, -24VDC is applied to terminal 15 and current
flows through alarm relay Kl (energizing the re-
If an open occurs in the supervised lines, super-
lay), through contacts K2B (56~8) to +24VDC at
visory relay K3 de-energizes and its contacts trans-
terminal 11.
fer.
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