TM 9-6115-624-BD
CHAPTER 7
DC ELECTRICAL SYSTEM
BDAR FIXES SHALL BE USED ONLY IN COMBAT OR FOR TRAINING
AT THE DISCRETION OF THE COMMANDER
(AUTHORIZED TRAINING FIXES ARE LISTED IN APPENDIX E)
IN EITHER CASE DAMAGES SHALL BE REPAIRED BY STANDARD
PROCEDURES AS SOON AS PRACTICABLE
Section I. INTRODUCTION
7-1. Scope. DC Electrical systems on most generators (figure 7-1) are 24 volt negative ground, direct current systems.
Electrical storage for starting and standby circuits is provided by batteries. The batteries are connected in a series-
parallel configuration to provide 24V dc current. In most of the larger generators there are many safety circuits to
prevent accidental damage to the generator through mechanical failure. For example, if the oil pressure drops too low, a
safety circuit will shut down the generator. These safety circuit will shut down the generator. These safety circuits can be
bypassed with one master switch called the "Battle Short" switch. Use of this switch is to be limited to absolute necessity
because severe damage to the generator may ensure. The "Battle Short" switch on the DOD 15-200KW Diesel Engine
Driven Generator Sets bypasses all of the safety devices except the overspeed switch and the short circuit relay.
7-2. Assessment Procedure. DC Electrical system assessment procedures are structured using the logic process
shown in figure 7-2. Visually inspect the system for damage to components. Then start up the generator and observe
operation.
7-3. Repair Procedure Index.
Damage
Paragraph
Battle Short Switch, Defective ............................................................................
Switch, Starter Inoperative ..................................................................................
7-6
Fuse or Circuit Breaker Failure ...........................................................................
Wiring Harness Damage .....................................................................................
Connector Pin, Damaged (Broken or Missing) ....................................................
Wires Broken ......................................................................................................
Cable, Heavy Duty, Damaged ............................................................................
Brush, Electrical, Alternator/Starter-Motor, Worn ................................................
Starter Solenoid Defective, Delco-Remy Only ....................................................
Battery Terminal Post, Broken ............................................................................
Battery Cracks ....................................................................................................
7-1
