Advanced HV-lab testing and condition assessments

BBA’s HV lab offers industry standard qualification testing and highly specialized assessment of MV cables and accessories:

Design tests for MV cable accessories: For extruded and laminated dielectric shielded cable accessories (joints and terminations) rated from 2.5 kV to 44 kV, as a part of cable accessory design or qualification. Design testing involves performing a sequence of electrical tests so that the cable, joint or termination design, any materials used as well as the overall manufacturing process can be certified. METSCO, now known as BBA, performs qualification design testing of MV cable joints and splices in accordance with IEEE Std. 48/404, ICEA S-94, CSA C68.3, or IEC 60502-4:

• Partial discharge (PD) measurement
• AC voltage withstand test
• Basic impulse level (BIL) or lightning impulse voltage withstand test
• Cyclic aging test
• High-voltage time test o DC voltage dry withstand test
• Accelerated water absorption test
• Capacitance and dissipation factor (C&DF) measurement
• Insulation resistance measurement
• Conductor and shield resistance

Long-term testing of cables: Including long-term insulation resistance (LTIR), accelerated water-tree test (AWTT), accelerated water absorption and long-term water stability tests in alignment with applicable CSA, UL and ICEA standards for LV/MV cables qualification.

BBA’s HV lab provides design, qualification and production testing of air, vacuum and gas-insulated switchgears (GIS), pole-mount switches, bushings, CT/PTs, breakers and assemblies rated 750 V and above up to 69 kV in order to verify their conformance. The lab is equipped with current transformers for temperature-rise tests and load-cycling tests up to 2000 A continuously and 3000 A temporarily. All tests can be performed in accordance with the client's specification or an agreed CSA, IEEE or IEC standard.

Distribution transformers are critical in the power delivery and distribution chain. BBA’s subject matter experts and the HV lab crew have extensive expertise in performing and witnessing type and routine testing of power transformers. The BBA HV lab is equipped to perform most electrical tests for distribution transformers of up to 5 MVA, including:

• SFRA
• TTR, DC winding resistance
• Capacitance and power factor as well as DFR
• Induced voltage test and partial discharge
• Applied voltage test
• Lightning impulse test

MV cables and accessories: The cables and accessories root cause analysis (RCA) and investigation includes gathering failure event data, a comprehensive visual inspection, possible electrical tests (e.g., IR, PD, AC withstand, AC breakdown, C&DF, hot-oil, insulation wafering and dimensional analysis, wafer boiling and dyeing in accordance with CSA C68.3, ICEA S-94-649, ICEA S-97-682, AEIC CS9-06 standards) or client specifications.

The lab provides a unique condition assessment for “retired cables” by performing a breakdown test on extracted cable samples to determine the “true remaining life” of the cable. This data is used to confirm that replacement was necessary as well as providing information for similar cables in service.

Liquid-filled and dry-type power and instrument transformers CT/PT/CVT: Dissection and visual inspection, contamination intrusion, power factor testing, PD measurement, dielectric withstand (AC, impulse, wet test, salt fog/spray test), paper extraction and analysis such as radial power factor testing, degree of polymerization, breakdown test, dielectric frequency response and thermal cycling can also be performed on components.

Switches and switchgears: Visual inspection, insulation resistance, DC contact resistance, power factor testing, PD measurement, dielectric withstand (AC, impulse, wet test, salt fog or spray test), thermal cycling and component dissection.

Because of our broad expertise in HV testing and condition assessments as well as our exceptional testing facilities, BBA is in a unique position when it comes to helping clients improve their product quality, reduce the risk of failure and understand the true condition of an asset. As a third-party, independent laboratory and having access to world-renowned subject matter experts, BBA can offer the best industry practice in accordance with the latest standards. If you’re interested in basic or advanced HV testing services, feel free to contact Ali Naderian (ali.naderian@bba.ca) or Shanon Lo (shanon.lo@bba.ca) for more details.