CHAPTER 6 FUNCTIONING OF EQUIPMENT - TM-5-6350-262-14-70014

TM 5-6350-262-14/7/NAVELEX 0967-466-0970/TO 31S9-4-28-1

CHAPTER 6

FUNCTIONING OF EQUIPMENT

operated and latched, the closed relay contacts provide a

6-1. General.

continuous duress alarm signal path and a return path

for current flow through light emitting diode (LED) CR1.

This chapter contains a circuit description for each of the

(Diode CR2 protects alarm switch components from

equipment operation modes (i.e., no alarm condition,

possible damage due to reverse polarity of the 20-V dc

duress alarm, duress alarm reset, and tamper alarm)

input power if input leads are improperly connected

Explanations are keyed to the alarm switch schematic

during installation or maintenance.) Illumination of diode

diagram shown in figure 6-1.

CR1 indicates that a duress alarm signal is present at

the output terminal strip. This duress alarm condition will

6-2. No-Alarm Condition.

exist until the circuits are reset.

A no-alarm condition exists when circuit components are

6-4. Duress Alarm Reset

restored as shown in figure 6-1. Switches S1 and S2 are

momentary or spring-return push button switches.

Once the alarm switch has been latched in the duress

Tamper switch S3 is held in the CLOSED position by

alarm condition, it must be reset to the no-alarm

proper installation of the alarm switch cover. Relay K1

condition for further use. When reset switch S2 is

contains reed contacts which are magnetically latched in

pressed momentarily, 20 volts dc is applied to the coil of

the last position in which they are operated. In this

latching relay K1B. Operation of relay K1B restores the

condition, a no-alarm signal is presented to the Alarm

relay contacts to the no-alarm condition described in

Set Control Unit C-9412( )FSS-9(V) via a circuit

paragraph 6-2.

impedance of 2000 ohms or less between terminals TBl-

1 and -2, and between terminals TB1-5 and -6.

6-5. Tamper Alarm.

6-3. Duress Alarm.

Tamper switch S3 opens in the event the alarm switch

cover is removed in an attempt to disarm the duress

Whenever an operator actuates duress alarm switch S1,

alarm function. The resultant high impedance of 100,

the low impedance signal patch between terminals TB1-

000 ohms or greater between terminals TB1-5 and -6 is

1 and -2 is broken. The resulting high circuit impedance

used as the tamper alarm signal output. Replacement of

of 100, 000 ohms or greater is used as the duress alarm

the alarm switch cover actuates tamper switch S3 to the

signal output. Simultaneously, 20 volts dc is applied to

closed position and restores the output to the no-alarm

the coil latching relay KLA through normally open

condition described in paragraph 6-2.

contacts of duress alarm switch S1. With relay K1A

6-1