This column features helpful information, innovative equipment, systems and applications utilities around the nation can use to save energy and improve service.

When the flood comes, will you be ready?

by Johnny Douglass

In the wake of Hurricane Katrina, it is a good time to remind ourselves that floods happen nearly everywhere, sometimes with cataclysmic results. A devastating flood has the potential to affect everyone, at least indirectly, whether they are located in the flooded area or not. Are we prepared to survive and make a timely recovery from it?

Restoring electrical apparatus

Getting electric power back on is a top priority, and utility personnel from around the country are working night and day to restore power knocked out by Katrina's flooding. However, the wheels of industry and commerce will not turn until flooded transformers, motors and other electrical apparatus go through an urgent triage and are repaired or replaced.

Flooded motors and transformers will be sent all over the U.S. to be restored to serviceability. According to the Electrical Apparatus Service Association, even motors submerged in salt water may be restored if properly cleaned, dried and tested.

Owners must take the first step of trying to keep the windings flooded, or at least wet, until they can be flushed in clean fresh water. If salt water dries in a winding, it is much harder to dissolve and remove the salt by flushing.

Utilities, industries, commercial facilities and electrical apparatus service centers need to know something about restoring flooded equipment. EASA provides several resources on its website, including two good articles on flooded motors by EASA Technical Support Specialist, Chuck Yung:

• Procedure for Flushing Saltwater from Windings describes how to construct a large washing tank from available materials to remove saltwater from windings. Even saltwater-submerged motors and transformers can recover if salt and other contaminants are flushed out and the equipment is properly dried before being tested and powered. Drying cannot happen in any reasonable time without heat, so the following article is critical to the process.
• Field-Expedient Ovens addresses how to construct a temporary oven to dry out large or multiple motors after flooding. The article also describes a method to determine when the windings are dry while the apparatus is still in the oven.

After the windings are dry, they need to be tested. Insulation Resistance Testing: How Low Can Megohms Go?, by Tom Bishop, can be helpful. Other information on resistance testing in repaired motors is available in ANSI/EASA Standard AR100-2001. Select the "Industry Info" button on the EASA home page to download the recommended practices.

The EASA articles are intended for service centers swamped with flooded equipment. However, they describe ways to conduct tests of dryness and insulation integrity using commonly available materials. If service centers are backed up for weeks, major industrial facilities may be able to set up temporary "field hospitals" for flooded motors. However, this work needs to be at least supervised, if not performed, by trained electrical equipment service personnel.

Before a flood happens

There are not a lot of ways to waterproof motor drive systems, but keeping critical systems on high ground can help to protect them. Here are some suggestions to help prepare for large or small equipment damage.

• Motor systems management software like MotorMaster+ can track motor inventory and identify in advance which motors are candidates for replacement if they become compromised. Be sure to back up these records in an off-site location.
• Multi-facility companies should store some critical spare parts at various facilities so they will survive a disaster that hits one facility.
• Determine if company service centers have a plan for restoring a large volume of flooded motors.
• Invest in a predictive maintenance program for motors and transformers, including diagnostic equipment that assesses insulation integrity. This will provide baseline information on insulation condition and identify problem equipment that needs rewinding or replacement. It can also help improve equipment reliability even in dry times.

Not all catastrophes can be avoided, but you can lay the ground work in advance for your recovery.

(Note: Douglass is a registered professional engineer with the Energy Services Clearinghouse.)