13,000 Spacers Were Replaced in a 13.2kV Distribution Line
A distribution company in Tucuman, Argentina purchased and installed 13,000 polymeric spacers on their 13.2kV lines. Shortly after the line started operating the maintenance teams observed and reported some unexplained physical changes on the spacers.
Physical design is an important factor in the Electric field distribution and when disturbed corona may appear, the distribution company decided to send few samples to Electro-technical lab in Tucuman University for analysis.
The testing of the spacers reveled that after a short period of time a large intensity of constant corona that turned into arcing appeared on the spacers until the spacers heated up and melted. This caused changes in the design of the spacers inflicting malfunctioning.
In order to assess and examine these physical changes, the company contacted Ofil and asked for a demonstration of the DayCor® Superb UV camera. DayCor® Superb outstanding performance showed corona discharge on each and every installed polymer spacer.
Following the inspection performed by Ofil's DayCor® Superb all the polymeric spacers were replaced. The spacers' manufacturer replaced all the spacers valued at 130,000 USD. The distribution company removed and re-installed 13,000 polymeric spacers, and thereafter tested the lines to guarantee that the new batch of spacers is flawless. The distribution company purchased Ofil's UV camera soon after.
Spacer-cable system is being used by utilities mainly to solve space constraints issues. Such a system is effective when there is
- A limited right of way - no available land for additional open wire circuits
- A demand for additional circuits in an existing right-of-way corridor while keeping configuration and clearance requirements
- Tendency to use of existing poles
A spacer-cable system includes polyethylene spacers to keep cables from rubbing and wearing. A series of spacers are clipped to the top of a messenger wire and support, separate, and clamp the phase conductors in a triangular or diamond-like configuration. The desired spacers are those which resist abrasion, withstand electrical tracking, and UV degradation.
To reduce the costs associated with electrical apparatus and to guarantee its reliability and durability, it is essential to monitor its operating conditions, its insulation system, and the working conditions of its accessories and other components. Early fault detection during commissioning of newly installed components or newly designed lines is mandatory, and more so if the tests are performed under real time conditions. Ofil's corona cameras enable nondestructive, not intrusive online monitoring of electrical systems. If indications of abnormality are found, it is important to carry out other complementary tests/diagnostics to ascertain the overall integrity and assessment to avoid unscheduled outages, financial/ revenue losses and environmental/ collateral damages.