News Release

July 1, 2002

Insulating Cables Helps Ensure Electric Reliability

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NEWS MEDIA CONTACT Susan Sponar Telephone: (505) 241-2768

Albuquerque: Some underground electrical cable installed in the 1960s and 1970s—although considered state-of-the-art at the time—was not manufactured to today’s standards, and is failing at a rate that increases every year. The result: electrical outages for customers. The cost-effective and guaranteed solution: CableCure, or injecting a fluid into the cable that fills the gaps and improves the insulation value.

“Existing cable gets progressively worse every year,” said John Myers, PNM vice president of construction and reliability. “One option would be to replace the cable, but that is expensive and typically requires trenching that disturbs existing landscaping.”

CableCure, on the other hand, is completed at the transformer boxes, with little or no environmental disruption. Here’s how it works: Older cable was manufactured with voids and contaminants in the insulation. Insulation is necessary to isolate the neutral wires from the energized conductors, so it experiences a high electrical stress. The liquid CableCure (the exact ingredients are a trade secret of the manufacturer) fills the voids which, if left vacant, can cause arcing and, ultimately, a fault resulting in an electrical outage. Just how many customers are affected by the outage depends on the location of the fault, but it can easily climb to several hundred.

“This process allows us to prevent outages from occurring, and at about one-third the cost of putting in new cable,” said Myers. “At the same time, we get a 20 year guarantee on the liquid injection.”

Since February of 2001, PNM has “cured” about 90,000 feel of underground cable, and plans to do an additional 50,000 feet this year. The cable is all underground residential primary cable, mainly that which runs between transformers. The company first targeted areas that had demonstrated failure patterns, and then moved on to other locations, based on the age of the cable.

“We are constantly upgrading the system in one way or another,” said Myers. “Our goal is to minimize interruptions in service to customers…to keep the lights on, if you will.”

At the same time PNM is curing cable, it is also replacing some cable. The decision hinges on the cost, with curing being the choice if it costs less than 60 percent of putting in new cable. Myers said that new cable has a life expectancy of about 40 years.

PNM is a combined electric and gas utility serving approximately 1.3 million people in New Mexico. The company, a wholly owned subsidiary of PNM Resources, also sells power on the wholesale market in the Western U.S. PNM Resources stock is traded primarily on the NYSE under the symbol PNM.