1.2.2 Normal Condition
The circuitry in Figure 1-2 shows the positive DC voltage on the left side
and the DC return on the right side. A closer study reveals several
parallel paths for potential current flow.
In the Normal condition, full potential is applied causing:
o AC pilot lamp to go ON (between terminals 2 and
3)
o AC monitor relay (K3) to energize
o Relay K3 contacts 1 and 3 to close applying normal power
to the rest of the circuit.
Detector power is applied to teminals 23 and 24. Supervisory current is
applied through to the following supervised series circuit:
o High detector loop (between terminals 28 and 25)
o Resistor R2
o Milliamp meter (between terminals
4
and
5)
o
AC
monitor relay (K3) contacts
8
and
6
o Trouble relay (K2) coil (pins
7
and 2)
o Resistor R3 (between terminals 12 and 11)
o Circuit trace (between terminals 11 and 21)
o Bell circuit end-of-line (EOL) diode
(between terminals 21 and 22)
o Alarm Silence switch (S2) contacts
A
(between terminals 22 and 26)
o Low detector loop (between terminals 26 and 27)
o Alarm relay (Kl) coil (pins 2 and 7).
The momentary Test switch S4 (between terminals 25 and 26) is used to Alarm
test the system. The momentary Reset switch S3 is used to reset the system
to Normal condition.
The standby battery is connected to terminals 13 and
14.
Fuse F3 protects
the circuitry when battery power is used.
555
M
DOCUMENT
NO.
001-097-00
PAGE
Monaco
Ente~p~ises
INC.
SPOKANE. WASHINGTON
99214
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