RECOMMENDED PRACTICE FOR INSULATION TESTING OF AC ELECTRIC MACHINERY (2300 V AND ABOVE) WITH HIGH DIRECT VOLTAGE
Institute of Electrical & Electronics Engineers
1 Overview
1.1 Scope
1.2 Purpose
1.3 Application and limitations
2 References
3 Definitions
4 Test preparations
4.1 Safety precautions required for high direct-voltage tests
4.2 Influencing factors
4.3 Gas-cooled machines
4.4 Liquid-cooled machines
4.5 Isolation of the winding from cables and auxiliary equipment
4.6 Sectionalizing the winding
5 Test equipment and connections
5.1 High direct-voltage test equipment
5.2 Discharge and grounding provisions
5.3 High-voltage test connection to the winding
5.4 Test connection to ground
6 Test procedure: proof tests
6.1 Test voltage for acceptance proof testing
6.2 Test voltage for maintenance proof testing
6.3 Voltage application
6.4 Discharging and grounding
6.5 Test results
6.6 Insulation failure
7 Test procedure: controlled overvoltage test
7.1 Test method
7.2 Test setup
7.3 Measured current
7.4 Test voltage for controlled overvoltage testing
7.5 Initial voltage level
7.6 Voltage increments
7.7 Discharging and grounding
7.8 Test results
7.9 Use of controlled overvoltage tests
8 Fault location
9 Suggested test record
Annex A (informative) Test Procedures
Annex B (informative) Bibliography
Provides uniform methods for testing insulation with high direct voltage. Applicable to stator (armature) windings of ac electric machines rated 2300 V or higher. Covers acceptance testing of new equipment in the factory or in the field after installation, and routine maintenance testing of machines that have been in service. Purpose is to: a) Provide uniform procedures for performing high direct-voltage acceptance tests and routine maintenance tests on the main ground insulation of windings of ac electric machines. b) Provide guidance in analyzing the variations in measured current versus applied voltage so that the condition of the insulation can be more effectively assessed. c) Compare direct-voltage testing with alternating voltage testing.
| Document Type | Standard |
| Status | Current |
| Publisher | Institute of Electrical & Electronics Engineers |
