Nature is biggest obstacle for power

Thursday, November 7, 2002

SIKESTON - Digital clocks, videocassette recorders, personal computers, DVD players - the list of electronic items in our homes just keeps growing.

As the list grows, so does our irritation with power interruptions.

"That's what's changed - the need for reliability for the system," said Wayne McSpadden, operations manager for the Board of Municipal Utilities. "Our world is less tolerant now to power outages than it used to be."

Nature is the biggest obstacle to providing uninterrupted power to customers. "We can trace the majority of our outages to trees and animals," McSpadden said. "Trees are a major problem when it come to guaranteeing reliability for our customers. Tree limbs interfere with power lines, and when they do that it creates an electrical fault."

"Tree trimming is our best defense against a lot of the outages that do happen in our system," McSpadden continued. "Tree trimming is a necessity to operating an electrical system."

For the last 15 years, BMU has bid out its tree-trimming duties. The contract is rebid every three years.

BMU spends roughly $200,000 each year trimming trees - money well spent in reducing power outages and reducing maintenance costs, according to McSpadden. "It probably pays for itself."

The present contractor, Trees Inc., has been trimming trees for BMU for about a year and a half now.

"We feel like they've been doing a real good job for us, doing what we ask to provide the clearances that we need," McSpadden said.

BMU uses American National Standards Institute guidelines for their trimming operations, McSpadden explained, which advise clearance of roughly 10 feet for the 13,800 volts of BMU's distribution system.

While 10 feet in clearance may have drastic results for trees located too close to power lines, residents need to keep in mind the goal is to provide hazard-free operation for at least two years.

"We fully understand that these trees are valuable to the landowners," McSpadden said. "But if they're planted under a power line they're going to get trimmed back from time to time."

BMU tries to conduct its trimming activities in a "user-friendly manner," according to McSpadden, but crews are not always able to reach residents before the work must be completed. "We do make an effort."

"We try to educate our customers more than we did in the past as to why we need to trim and beg their patience and understanding when we have to go out and do that," said McSpadden. "It's all for their benefit in the end."

The 10-foot margin also prevents squirrels from jumping from trees to the power lines.

When the limbs are allowed to grow too close, "It also gives a squirrel an easy route to a power line," McSpadden said. "They use our power lines for highways until they get near a congested area such as at a pole with transformers."

Then, once they touch two conductors, "It creates a fault condition and electrocutes them," said McSpadden. "We kill a lot of squirrels this way each year."

The fault caused by connecting the two conductors can cause a "tap fuse" to blow. "We have to go find that and refuse it, repair any damage that's been caused by that fault, and get service back up."

All of which can sometimes take up to an hour to track down and fix.

While it is frustrating for residents, for area industries that depend on BMU power, outages also mean lost revenues from production set backs - even from momentary interruptions.

"It shuts us down," said Clovis Delwiche, engineering manager for Sikeston Good Humor-Breyers. He said they can pretty much expect an hour of lost production at his plant for a five-minute power loss at a cost of around $400-$500 for each hour of down time. "It doesn't happen very often," Delwiche added. "Usually just during a lightning storm which they can't do anything about."

McSpadden said BMU is a member of the American Public Power Association and participates in their "Treepower" program which provides customers with coupons for up to $25 off at local nurseries.

"We like to encourage people to plant trees, but just in the right spots," said McSpadden. "We encourage anyone considering planting trees to pay attention to where they are planting them. Plant it far enough away from power lines that when the tree reaches its full maturity the 10-foot clearance is met."

Customers with any questions about trees and power lines are encouraged to call the BMU at 471-3328.

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