M2/M3 BFV: HULL POWER DIST SYSTEM - OD1606 - LESSON 1/TASK 1
particular instance, it is used to connect the two sets of batteries
in the power control compartment.
Paragraph 3a, on the previous page, explained that the electrical
system on the M2/M3 used four wet cell batteries.
are positioned two on each side of the power control compartment.
The batteries are then connected through the use of an electrical
lead connected to the bus bar, which is in the center between the two
Battery Simplified Test Bquipment/M1 Fighting Vehicle System
(STE-M1/FVS) Shunt. The battery STE-M1/FVS shunt is merely a switch
that is parallel to the batteries. It provides a connection for the
STE-M1/FVS test set.
When the test set is connected, the shunt
divides the circuit current so that half of the current travels to
the STE-M1/FVS test set and the other half goes to the resistor.
Master Battery Switch Relay.
A relay is an automatic switch,
having one or more contacts, some of which are normally closed or
It is used to control the operation of one or more
circuits at the same time.
Relays work on an electromagnetic
Current passing through a relay coil temporarily
magnetizes an iron core inside of the coil. This attracts a lever or
armature which opens and closes a switch.
When the current stops
flowing in the coil, the lever returns to its original position,
usually by means of a spring.
The master battery switch relay opens to allow battery voltage to
It closes to allow the current flow to come from the
This is the last component in the hull power
distribution system. It is located on the driver's instrument panel.
The volts gage provides the driver with an indication of battery and
(1) Left Red Zone. Indicates low battery charge with the engine
off. Batteries may not start the engine.