IEEE 400-1991

400-1991 is a technical standard for Voltage Tests on Power Cable Systems in the Field, providing guidance for evaluating cable system integrity under site conditions. It is relevant to power, energy, and industry applications where field testing helps confirm insulation performance and installation quality. As a superseded standard, 400-1991 remains useful for understanding the testing approach it defined and the engineering practices surrounding acceptance and maintenance testing of power cable systems.

What is 400-1991?

400-1991 addresses voltage testing of power cable systems after installation or during service in the field. The standard focuses on how electrical tests are applied to installed cables, joints, terminations, and related components so that engineers can assess dielectric condition and identify weaknesses before operation or return to service. In practical terms, it supports controlled testing procedures for cable insulation systems, helping users apply consistent methods when verifying the condition of medium- and high-voltage cable installations.

Where is 400-1991 used?

This standard is commonly used in utility, industrial, and infrastructure settings where power cable systems must be checked on site. It is relevant for commissioning crews, maintenance teams, and test engineers working on underground distribution circuits, plant feeder cables, substation-related cable runs, and similar installations. 400-1991 can help guide field testing workflows for acceptance, troubleshooting, and periodic evaluation when cable performance and insulation condition need to be confirmed under real operating conditions.

Why is 400-1991 important?

400-1991 matters because field voltage testing carries direct implications for safety, reliability, and asset condition. A clear technical basis for test methods helps reduce inconsistent practices, supports more repeatable results, and improves confidence in whether a cable system is fit for service. For procurement, maintenance planning, and compliance checks, the standard can also provide a useful reference point when specifying test expectations, documenting results, or comparing engineering practices across cable installations.

• Voltage testing for installed cable systems
• Field evaluation of insulation condition
• Acceptance and maintenance testing reference
• Power cable components, joints, and terminations
• Utility and industrial power applications