Distribution Class Cables and Cable Accessories - Testing, Evaluation and Failure Analysis
Powertech’s multidisciplinary team performs failure analysis an on all types of electrical equipment, including distribution class cables and accessories. Our expertise in electrical, chemical and materials engineering, as well as power system analysis, and protection and control allows us to evaluate all aspects of a failure.
Powertech Labs offers standard tests, and specialized evaluation and research on all types of distribution class cables and accessories. The types of cable insulation include XLPE, PILC and EPR. Accessories include Separable Insulated Connectors (Elbows, Bushing Inserts, Junction-Bars, etc.), Terminations and Splices. We are familiar with all designs of accessories from the older taped and pre-molded to the newer heat- or cold-shrink technology. Our third party, independent status enhances manufacturer’s credibility in their test reports. Many utilities specify independent testing of products in their specification. Powertech Labs is a trusted name with a worldwide reputation in the area of cable testing and cable accessories.
Cable Accelerated Aging Tests
We offer both Acceleration Cable Life Test (ACLT) and Accelerated Water Treeing Tests (AWTT) on the polymeric cable insulations. Tests can be performed in tanks and conduits to AEIC, IEEE, IEC and other standards. These tests are designed to accelerate the dielectric ageing of cables by applying electrical and thermal stresses to cable samples at levels in excess of their normal ratings We offer both the time-to- failure and fixed time with concluding breakdown tests.
Termination and Splice Tests
Powertech can provide a number of standard accelerated cable aging tests for terminations and splices. These cables tests provide both current cycling and elevated voltage application during the tests. Diagnostic evaluation, including partial discharge, before and after the aging tests can be provided. Standards include IEEE-404 or IEEE-48, as well as IEC and others. Specialized test, including though fault current and temperature rise tests can be performed.
Separable Insulated Connector Testing
In addition to current cycling and high voltage tests, we perform load make/break and fault closure tests at operating voltage, as required by most Separable Insulator Connector (SIC) standards. The most common North American standard to which we test is ANSI-386.
Partial Discharge Measurements
We can measure partial discharge (PD) levels, as well as inception and extinction voltages in cables and accessories. PD is often used as a pass/fail criterion in standard tests of as a diagnostic tool in the design process. Our experienced staff can often locate sources of PD using modern phase resolved and ultrasound techniques.
Impulse and AC Withstand or Breakdown Tests
Powertech conducts both switching surge and lightening impulse tests on power cable and accessory samples. Thermal stresses can be incorporated into these tests if required. AC withstand or breakdown tests are conducted to levels in excess of 700 kV rms. We have water terminals for both AC and impulse tests if required.
Power Cable Materials Qualifications
Powertech can assist cable manufacturers evaluating new cable designs, or utilities and electrical industries selecting the cable which best suits their needs. Our power cable materials qualification testing programs are designed to give the level of quality assurance required by the client. Full-scale cable qualification tests performed at Powertech conform to procedures outlined in AEIC standards CS-5, CS-6 and CS-7.
We also perform material evaluation using state-of-the-art equipment. Tests include Dielectric Thermal Analysis (DETA), Four Transform Infrared (FTIR) and other chemical evaluations to identify unknown materials and determine physical and electrical parameters.
Cable and Accessory Failure Analysis
Powertech’s team performs failure analysis on all types of electrical equipment, including cables and accessories. The advantage of a multidisciplined group is evident since failures may result from various stresses. One may consider electrical stress on cable insulation as a common failure mode, but many factors may lead to the failure. These include thermal stresses, corrosion, operating conditions and design factors. Our expertise in electrical, chemical and materials engineering, as well as power system analysis, and protection and control allow us to evaluate all aspects of a failure.
On-Site Cable Condition Assessment
We also undertake on-site cable condition assessment of installed cable systems for utilities and industrial plants. For more details, see Cable Condition Assessment.
Specialized Tests and Research
Powertech staff have been the principal investigators on specialized cable related projects for large research organizations. The organizations include EPRI, the Canadian Electricity Association, and the research sections of large utilities.