IEEE DRAFT 1375 : D5 AUG 97

1.0 Scope and Purpose
2.0 Definitions
3.0 References
4.0 Philosophy of Stationary Battery Protection
5.0 DC System Considerations
5.1.1 Use of a Battery Protective Device
5.2 Over and Under Voltage Protection
5.3 Grounding
5.3.1 System Grounding
5.3.2 Equipment Grounding
5.4 Temperature Compensation and Current Limiting
6.0 Batteries
6.1 Lead Acid Batteries
6.2 Nickel Cadmium Batteries
6.3 Battery Voltage Characteristics
6.4 Battery Current Characteristics
6.5 Battery Withstand Capability
6.6 Environmental and Operational Effects on
                Battery Short Circuit Current
6.6.1 Effect of Elevated Temperatures on Battery
                Short Circuit Current
6.6.2 Effects of Charging Voltage on Battery Short
                Circuit Current
6.7 Damage and Failures of Batteries
6.7.1 Internal Failure Mechanisms
6.7.2 External Failure Mechanisms
6.7.3 Battery Failure Modes Under Fault Conditions
7.0 Characteristics of Other DC Components
7.1 Battery Chargers Short Circuit Characteristics
7.2 Characteristics of Fused in DC Circuits
7.2.1 Principles of Fuse Design and Operation
7.2.2 Principles of Fuse Operation
7.2.3 DC Time Constants
7.2.4 Selecting Fused for Use in DC Circuits
7.3 Characteristics of Circuit Breakers in DC
                Circuits
7.3.1 Basic Function of a Circuit Breaker
7.3.2 Types of Circuit Breakers
7.3.3 Types of Circuit Breaker Trip Units
7.3.4 Thermal-Magnetic Characteristics
7.3.5 Ratings, Certification and Testing for Molded
                Case Circuit Breakers and Insulated Case
                Circuit Breakers
7.3.6 Ratings, Certification and Testing for Low
                Voltage Power Circuit Breakers
7.3.7 Application of Circuit Breakers in DC Circuits
7.4 Characteristics of Fused Circuit Breakers in
                DC Circuits
7.5 Switches
7.5.1 Switching Direct Current
7.5.2 Ratings
7.5.3 Design Tests
7.6 Use of AC Rated Devices for Battery Protection
7.7 Ratings Considerations for Devices Used in DC
                Systems
7.7.1 Voltage Ratings
7.7.2 Current Ratings
7.8 Main Battery Feeder Cables
8.0 Battery Electrical Protection Schemes
8.1 Fuses between the Battery Terminals and Main
                DC Panel
8.2 Circuit Breakers between the Battery Terminals
                and Main DC Panel
8.3 A Switch between the Battery Terminals and
                Main DC Panel
8.4 Cable Only between the Battery Terminals and
                Main DC Panel
8.5 Mid Span Protection
8.6 Multiple Voltage Battery Systems
9.0 Physical Protection of Batteries
10.0 Indication and Annunciation
Annex 1 DC System Time Constants
Annex 2 Sample Battery System Time Constant
                Determination
FIGURES
Figure 6.3-1 Lead Acid battery Typical Initial Voltage
                Characteristic During Short Circuit
Figure 6.4-1 Lead Acid Battery Typical Initial Current
                Characteristic During Short Circuit
Figure 6.5-1 Lead Acid Battery Typical Long Duration
                Characteristics During Short Circuit
Figure 7.2.1-1 Typical Bridges used in Fuse Link Construction
Figure 7.2.2-1 Time Constants for DC Circuits
Figure 7.2.2-2 Current as a Function of Time Constant During
                a DC Short Circuit
Figure 7.3.4-1 Typical Time-Current Curve For a Nonadjustable
                Thermal-Magnetic Trip Unit
Figure 7.3.4-2 Characterist Curve for a Thermal-Magnetic MCCB
                Modified for DC Application
Figure 7.3.5-1 Common Circuit Breaker DC Connections
Figure 7.4-1 Typical Time-Current Characteristics of
                Circuit Breakers in Series With Fuses
Figure 7.7.1-1 AC Versus DC Voltage Regulation
Figure 7.7.2-1 Voltage Effects on Current
Figure 8.1-1 Fuses Between the Battery Terminals and Main
                DC Panel
Figure 8.2-1 Circuit Breakers Between the Battery Terminals
                and Main DC Panel
Figure 8.3-1 A Switch Between the Battery Terminals and
                Main DC Panel
Figure 8.3-2 Typical Fusible Battery Disconnect Switch
                Schematics
Figure 8.4-1 Cable Only Between the Battery Terminals and
                Main DC Panel
Figure 8.5-1 Mid-Span Protection For a 60 Cell Stationary
                Battery
TABLES
Table 7.2.3-1 Minimum Time Constants Used For 200% Overload
                Testing in UL 198L
Table 7.2.3-2 Minimum Circuit Time Constants for Overcurrent
                Testing Per UL 198M
Table 7.3.5-1 Time Constants Used in UL 489 Testing
Table 7.3.5-2 Typical Direct Current Interrupting Ratings of
                MCCBs for Commercial and Industrial
                Applications
ANNEX FIGURES
Figure A1-1 Schematic of a Simple Battery System
Figure A1-2 Short Circuit Current Rise as a Factor of Time
                Constant
Figure A1-3 Circuit Inductive Voltage
Figure A1-4 Short Circuit Current Interrupted by
                Protective Device
Figure A1-5 Voltage Applied Across Protective Device
Figure A2-1 Single Line Diagram of Sample Battery System
Figure A2-2 Battery Short Circuit Test
Figure A2-3 Transient resistance of DC Motor Armature
                Circuit
Figure A2-4 Battery Cable Configuration
Figure A2-5 Motor Load and Non-Motor Load Cable
                Configurations
Figure A2-6 Equivalent Circuit with Bolted Fault at the
                Fuse Load Side Terminals
Figure A2-7 Equivalent Circuit with Bolted Fault at the
                Non-Motor Load Terminals

Provides guidance in the protection of stationary battery systems. Stationary battery systems include the battery and dc components to and including the first protective device downstream of the terminals.