freightliner M2 Plus 2023 Manual page 227

is meant to serve as a supplemental warning only. It
is not intended to replace standard safety practices
that should be conducted around flammable gases.
IMPORTANT: To function properly, the gas
detection system must be powered at all times.
The gas detection system is directly powered by
the batteries, and can only be powered off by
disconnecting the batteries. When servicing a
natural-gas-fueled vehicle, disconnect the
batteries only when necessary, and do not leave
the batteries disconnected for extended periods
of time.
The lower flammability limit (LFL) is the smallest
amount of the gas that supports a flame when mixed
with oxygen and ignited. Zero percent (0%) LFL
indicates a gas-free atmosphere. One hundred
percent (100%) LFL indicates that gas concentration
has reached its lower flammability limit (5% gas in air
by volume). The red warning light and audible alarm
located in the overhead console activate when a
sensor detects gas fumes in concentrations above
50% LFL, and should allow ample time to utilize
safety procedures. However, individuals with special
needs should review the system with a professional
safety engineer.
Alarm Procedure
Before operating the vehicle, the driver must be
familiar with the procedures as shown on the interior
sticker on the overhead panel, shown in
and the exterior sticker on the door shown in
Fig. 19.6.
10/22/2021
Fig. 19.5, Interior Warning Sticker
Natural Gas Vehicle Information
10/22/2021
IMPORTANT: If an audible alarm activates, do
not operate any electrical switch, including
lights. Avoid causing sparks and stay away from
arcing switches and equipment. Do not use a
Fig. 19.5
phone or any electronic device that have a
battery.
If the vehicle is in motion when the audible alarm
activates, bring it to a safe stop, shut down the
engine, and exit the vehicle. Do not open the hood.
If outside the vehicle when the audible alarm
activates, do not open the cab door or hood.
In the event of an audible alarm, immediately follow
these procedures, as allowed by conditions:
1. Immediately shut off all engines. Extinguish any
cigarettes, pilot lights, flames, or other sources of
ignition in the area and adjacent areas.
2. Manually close all fuel shutoff valves, including
those on the LNG tank or CNG cylinders.
3.
If the vehicle is indoors (as in a service shop),
immediately open windows and doors to provide
f080157
extra ventilation to the area. Do not start the
engine or any other type of equipment until the
Fig. 19.6, Exterior Warning Sticker
f080158
19.6