/images/PowerCableUpdate.jpg/images/southwire_100x70.jpgCable Fire Shows Cost of Smoke DamageCableFireShowsCostofSmokeDamage.htmWhen flames spread through a cable shaft, heat and smoke effects cost millions.
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Cable Fire Shows Cost of Smoke Damage

When flames spread through a cable shaft, heat and smoke effects cost millions.

A recent cable fire at a Tennessee Valley Authority (TVA) hydroelectric plant is a $30 million example.

“It all started when damaged cable insulation allowed arcing to a metal grating,” says Dave Mercier, technical director of Southwire’s Electrical Division. “That started a fire that spread along the cables in a cable shaft till control room employees saw smoke pouring into their work area.”

The fire was contained in the control building, but five workers were treated for smoke inhalation and the heat and smoke destroyed all the cabling and power plant controls in the cable shaft and control building. Damage may run to $30 million. When flames spread through a cable shaft, heat and smoke effects cost millions.

Low-smoke cables would have minimized damage

A standard requiring low-smoke non-halogen cables had been put in place not long before the fire, but the plant was built in 1942, so many cables were not fire-retardant, and none were low-smoke rated. Mercier comments. “The spread of the flames – and equipment damage from corrosive smoke – multiplied the cost of the fire.”

Modern low-smoke, non-halogen fire-retardant cables could have greatly reduced the impact of the incident by keeping the fire local and preventing equipment damage from corrosive smoke. That would have minimized the damage and the time needed to restore operations.

Cabling being installed after the fire includes fire-retardant low-smoke, zero halogen jacketed cables that provide an effective fire stop. “With low-smoke cables, if you do get a fire, there is not enough smoke to migrate to other areas,” says Mercier.

Low-smoke standards becoming widely accepted

“One of the interesting things about the incident is the timing,” Mercier says. “The requirement for low-smoke cables was not put in place as a reaction to the damage. The standard was already there, but there had not been time to replace the cabling.”

Mercier concludes, “Low-smoke, non-halogen requirements are becoming commonplace. TVA now requires this cable construction for all their hydro and fossil-fuel plants, and a major southeastern utility company recently added it to their approved list. People are seeing the benefits and adopting the standards.”