Section III. OPERATION UNDER UNUSUAL CONDITIONS

TM 3-6665-225-12

Section III. OPERATION UNDER UNUSUAL CONDITIONS

CLOSED position (fig. 2-5, A). Unscrew plug (1).

2-14. General

h. Press ZERO ADJUST knob (5, fig. 2-1), rotate

This section contains instructions for operating the

it fully clockwise and release it. Rotate HORN VOL-

equipment in tropical environments, in tempera-

BATTERY TEST knob fully clockwise.

tures below 40F., in blowing sand or dust, and in

i. Notify personnel within audible range that

raining, sleeting, or snowing environments.

alarm system is to be tested.

NOTE

In tropical environments, inspect the M42

If any startup tests fail, refer to table 3-3

alarm unit batteries every 15 days for elec-

for operator's troubleshooting information.

trolyte leakage. Replace defective batteries

j. Startup M43 detector unit as follows:

immediately. Replace batteries installed in

NOTE

M42 alarm units every 30 days as a mini-

In temperature below 40F., M43 detector

mum.

unit may require warmup to start pump

NOTE

assembly motor. Lower temperatures re-

If the alarm system is to be operational for

quire longer warmup, but no longer than

two or more continuous missions, perform

50 minutes.

checks and reservicing procedures (para 2-

(1) Connect power source connector to 24 VDC

10) after each 12-hour mission.

INPUT connector (11, fig. 1-2). If M10 power supply

is used, set power switch (3, fig. 2-2) to correct input

2-15. Operation in Temperatures Below

voltage position.

40F.

(2) If M43 detector unit horn (2, fig. 1-2) sounds

a. Perform preoperational procedures of para-

or pump assembly motor runs, proceed to (4) below.

graph 2-6.

(3) If horn does not sound or pump assembly

b. Remove one air filter package (7, fig. 1-6), one

does not run, M43 detector unit is in warmup mode.

sensitivity check bottle (6), and one reservoir as-

Do not proceed until M43 detector unit horn sounds

sembly (5) from M229 refill kit. Thaw liquid in sen-

or pump assembly motor runs. Then proceed to (4)

sitivity check bottle and in reservoir assembly if fro-

below.

zen.

(4) Position M42 alarm unit selector switch (8,

c. Install air filter (para 2-7d).

fig. 1-5) to HORN OFF, or disconnect one wire

NOTE

from M43 detector unit REMOTE binding post (17,

When operating between 40F. and 20F.,

fig. 1-2). Horn must be off. Disconnect power source

use either BA3517/U battery (7, fig. 1-1) or

from 24 VDC INPUT connector (11).

BB501/U battery (9, fig. 2-7) and M168 ca-

(5) Prepare solution as described in figure 2-3.

ble (5) as prime power source or standby

NOTE

battery for M10 power supply. When oper-

To prevent the M43 detector unit from

ating below 20F., use only BB501/U bat-

cooling off, keep bottom case assembly

tery and M168 cable as primary power

separated from detector assembly for as

source or standby battery for M10 power

short a time as possible.

supply. Use table 1-2 as a guide for deter-

(6) Release four clamping catches (12, fig. 1-2)

mining maximum number of missions be-

from bottom catches (13) and remove the detector

fore exchanging BA3517/U battery for a

assembly (6) from the bottom case assembly (9).

fresh battery or exchanging BB501/U

WARNING

battery for a freshly charged battery.

Solution in the reservoir assembly is caus-

d. Install alarm system in accordance with ap-

tic. Avoid contact with eyes and mouth.

propriate instructions in paragraphs 3-1 through

Flush from skin with water.

3-4.

CAUTION

NOTE

Keep weight assembly free from dirt after

Do not connect power to M43 detector unit

removing the reservoir assembly.

24 VDC INPUT connector until instructed

(7) Hold the detector assembly upright by its

to do so.

handle (2, fig. 1-3) and unscrew the reservoir as-

e. Remove AIR OUTLET cap (15, fig. 1-2) from

sembly (12). Allow the weight assembly to hang

AIR OUTLET port.

down. Discard used reservoir assembly in accor-

f. Remove electrical connector cover (10) from 24

dance with standing operating procedures.

VDC INPUT connector (11).

(8) Remove and discard cap from the pre-

g. Check that AIR INLET assembly is in

2-11

Change 2