Believe it or not, pure or distilled water is not conductive.  It is the contaminants that cause component and electrical degradation.  So, with much that has happened in the Southern USA, most of the submerged electrical equipment was exposed to grey water.  This is water that carries sewerage, chemicals, salt, decay and other contaminants that will reduce the electrical and mechanical reliability of your equipment.

What has happened to your electric motor:

1. The bearings have been exposed and will have started rusting;
2. The grease will be contaminated and may have separated;
3. Shaft, rotor and other rotating components have started rusting;
4. Contaminants have come into contact with the insulation system of the electrical conductors generating a condition that will degenerate or short if electrical energy is applied;
5. Stator mechanical components have rusted;
6. Let alone water in conduit, contacts, controls, etc.

Minimum necessary work:

If possible, send the motor in for reconditioning, clean, dip and bake.  This involves steam cleaning, drying in an oven, bearings replaced, mechanical surfaces checked and polished, rotor dried in oven, varnish insulation added to the existing insulation system in order to restore it.  Also, will identify problems that pre-existed.

With Babbitt bearings, the oil will be replaced and flushed.  With ball and roller bearings, they will be replaced and grease replaced.

If you are not able to remove the motor from its location, disassemble the machine and remove the rotor.  Clean the stator with clean water until all contaminants are removed.  Set up an insulated enclosure around the motor and, using either high wattage spot lights or space heaters (keep in mind all safety rules and perform at your own risk), allow the temperature to approach 200 degrees F at a rate of 20 degrees F per hour (this prevents moisture from flashing to steam and damaging the insulation system).  Perform insulation resistance readings periodically until the insulation resistance exceeds 500 MegOhms, or more.

For information on how to manage systems following flooding, contact howard@motordoc.net.  T-Solutions engineers have the experience necessary to assist you in coordinating your maintenance and reconditioning of facilities and machinery.

Dealing with Contaminated Electric Motors

Following this article, EASA responded with these additional recommendations for reconditioning motors that have been submerged in salt water.

Chuck Yung of EASA (The Electrical Apparatus Service Association), a recipient of the MDMH newsletter, responded and suggested that I publish a link to three EASA tech notes on flushing Salt Water from motors, Building a portable drying oven and Insulation Resistance Testing.

These can be found on the EASA Home Page: http://www.easa.com

Read more from Howard at the MotorBlog