Electrical overstresses can cause failure, permanent degradation, or temporary erratic behavior of electronic devices or systems. Manufacturers therefore must know how to evaluate the quality and appropriateness of insulation and isolation systems to assure the safety of electrical and electronic devices. ANSI C136.2-2023: Roadway And Area Lighting Equipment – Dielectric Withstand And Electrical Transient Immunity Requirements provides test procedures to evaluate the performance of luminaires and control devices.
What Is ANSI C136.2?
ANSI C136.2-2023 covers luminaires and control devices classified for up to 600 V operation for use in roadway and area lighting applications. It contains test procedures to examine the performance of luminaires, control devices, and (as applicable) combinations of luminaires and control devices, for the purpose of facilitating consistent performance reporting of such equipment. This American National Standard contains minimum performance requirements and test procedures for evaluating luminaire and control equipment under test (EUTs) for the following:
- Dielectric withstand
- Electrical transient immunity
Many factors can impact the dielectric withstand and electrical transient immunity performance of luminaires and control devices. ANSI C136.2-2023 maintains that EUT manufacturers that intend to characterize the performance of a family of products with the EUT should take care in determining the worst-case family member.
The test procedures contained in ANSI C136.2-2023 are not designed to evaluate the performance of components, such as surge protective devices (SPDs) or other varistor-based modules.
What Is a Dielectric Withstand Test?
In electrical engineering, a dielectric withstand test is an electrical safety test performed on a component or product to determine the effectiveness of its insulation. The test may be between mutually insulated sections of a part, or energized parts and ground. It involves placing an extra-high voltage across the insulation barrier of the device for one minute. If the insulation holds the voltage, the device is deemed to have passed the test. However, if the applied voltage leads to the sudden breakdown of the insulation material and allows current to flow, the insulation is determined to be insufficient since it might pose a shock hazard to users.
ANSI C136.2-2023 details that the dielectric withstand test potential should be applied to the equipment under test (EUT) using a test potential generator (i.e., a hipot tester) with a two-wire (high voltage, return) output configuration. Further, it should be performed by applying a 60-Hz alternating current (AC) test potential or a direct current (DC) test potential to the EUT. The selection of which test potential type to apply should be dictated by the EUT construction and documented in the test report. Usually, magnetically ballasted or un-ballasted EUT should be tested using the 60-Hz AC configuration, while electronically ballasted or driven DUTs should, unless noted otherwise, be tested using the DC configuration.
What Is a High Potential (hipot) Test?
The high potential (hipot) test is a test of the dielectric strength of the insulation to ground and is necessary to assure that current flows easily from one point to another. It verifies the integrity of the cable by determining whether the ground wall can handle an over-voltage situation. An over-voltage is a voltage higher than the peak operating (line-to-line) voltage of the EUT.
Hipot tests are used for everything from very low voltage devices to high voltage equipment. For medium to high voltage rotating equipment, direct current (DC) hipot tests called step voltage or ramp tests are used to see whether the start of an insulation breakdown can be detected. As the voltage is raised during the test, if a breakdown starts, the test can be terminated before there is an arc.
Electrical Fast Transient (EFT) Immunity Tests
Electrical fast transient (EFT) immunity is the ability of an electronic/electrical device to withstand the interference of electrical fast transients (EFTs). Thus, the purpose of EFT immunity tests is to demonstrate equipment immunity to fast transients resulting from switching. EFT immunity testing determines how electrical and electronic equipment operates under interference. This testing involves several tests to check the compatibility of a device with fast transients, such as power line transients and electrostatic discharge. ANSI C136.2-2023 details that equipment under test (EUT) manufacturers should test and evaluate EUT Pass/Fail in accordance with ANSI C82.77-5.
ANSI C136.2-2023: Roadway And Area Lighting Equipment – Dielectric Withstand And Electrical Transient Immunity Requirements is available on the ANSI Webstore.