Chapter 2. OPERATING INSTRUCTIONS - TM-3-6665-225-120015

TM 3-6665-225-12

CHAPTER 2

OPERATING INSTRUCTIONS

Section I. CONTROLS AND INSTRUMENTS

three-position rotary selector switch (8, fig. 1-5)

21. General

which allows manual selection of TEST HORN

This section describes the controls and instru-

OFF, or HORN ON. To operate in the HORN

ments of the M43 detector unit, M42 alarm unit,

OFF or HORN ON position, the M42 alarm unit

and M10 power supply.

must be connected to an operating M43 detector

22. M43 Detector Unit

unit.

a. Controls.

(1) TEST position. In the TEST position,

(1) Hand crank. The hand crank (2, fig. 2-1),

the ALARM-RED indicator will flash and the

located on top of the M43 detector unit is used

loudspeaker will sound. This is a functional test

to manually prime the fluid system of the M43

of the M42 alarm unit.

detector unit. It has a storage (up) position and

(2) HORN OFF position. In this operational

an operational (down) position.

position, when the M43 detector unit signals an

(2) AIR INLET assembly. The AIR INLET

alarm, only the ALARM-RED indicator will

assembly (4) is located near the lower-right-front

flash.

corner of the top. When in the open position, air

(3) HORN ON position. When the M43

can be drawn into the M43 detector unit for

alarm unit signals an alarm, and the selector

sampling.

switch of the M42 alarm unit is in the HORN ON

(3) ZERO ADJUST knob. T h e Z E R O

position, the ALARM-RED indicator will flash,

ADJUST knob (5) is located in the center-front

and the loudspeaker will sound.

portion of the top. The knob is used to set the

b. Instruments.

M43 detector unit during preoperational and

(1) Loudspeaker. The loudspeaker (5, fig.

operational procedures and to reset the unit after

1-5) is located on the panel (1). It provides an

an alert has been sounded.

audible signal during test and operation of the

(4) HORN VOL-BATTERY TEST knob.

alarm system.

The HORN VOL-BATTERY TEST knob (6) is

(2) ALARM-RED indicator. The ALARM-

located in the center of the M43 detector unit top.

RED indicator (3) is located on the panel (1).

When the knob is rotated, the horn output level

When activated during test or during operation, it

varies from minimum (LO) to maximum (HI).

flashes a visual warning.

Pressing in the knob connects the power source to

2-4. M10 Power Supply

the meter (1).

b. Instruments.

a. Control. The power switch (3, fig. 2-2) on

(1) Meter. The meter (1) is located on the top

the panel assembly (6) controls the application of

of the unit. It provides a visual indication of the

ac power to the M10 power supply. The power

power source voltage when the HORN VOL-

switch (3) has three positions:

BATTERY TEST knob (6) is pressed. Also, the

(1) 115V. Used for power input of 115 vac.

meter is used when setting the ZERO ADJUST

(2) OFF. Used to open input power circuit.

knob (5).

(3) 220V. Used for power input of 220 vac.

(2) Horn. The horn (3) is located in the

b. Instruments. The M10 power supply has a

upper-right hand comer of the M43 detector unit.

POWER ON indicator (2) and an annunciator (8)

The horn provides an audible signal when the

on its panel assembly (6).

detection circuits of the unit are activated.

(1) POWER ON indicator. The POWER ON

(3) FLOWMETER. The FLOWMETER (3,

indicator (2) lights when the M10 power supply is

fig. 1-3) is stored in the handle (2) of the M43

providing dc power.

detector unit. It is used to indicate the flow rate of

(2) Annunciator. The annunciator (8) is an

air drawn into the AIR INLET assembly (4, fig.

electrically-operated, manually-reset indicator.

2-1).

When the M10 power supply is operating from a

110-volt or 220-volt ac power source, the annunci-

2-3. M42 Alarm Unit

ator indication is all white. If a standby battery is

a. Control. The M42 alarm unit contains a

2-1