Effect of saltwater on electrical equipment 1

[Wills99]

We are rebuilding our island after Hurricane Ivan. Much of the island was under a 10-15' storm surge for 20+ hours. We have replaced a lot of switchgear but a lot of people are re-energizing the gear after drying it out. In the gear we have replaced we have seen a good deal of corrosion already and I am curious as to whether there are any studies or if there's any data available on what this kind of saltwater submersion could be expected to do to bus bars, circuit breakers, etc. over time.

 

[mjl2023]

I recommend you check the NEMA web site. They have a Guideline for Handling Water Damaged Equipment it is a PDF file that can be downloaded;

http://nema.org/index_nema.cfm/1426/D6EBB078-639B-4BBF-85DA2E30782D62C5

 

[LightningBolt]

The NEMA Publibication mentioned by mjl2023 is quite excellent as applied to fresh water incidents or sweet water as it is sometimes called.

Exposure to salt water splashing or spray with only surface contact can be easily resolved using plenty of warm fresh water to remove any salt with techniques as detailed in the NEMA Publication.

With Total Extended Emmersion however, in sea or brine water, the dissolved salts present a great problem. The water and dissovled salts are drawn into spaces between the conductor and insulation via capillary action and later salts solidify after drying. It is impossible to completely remove such salt deposits no matter how extensive the removal efforts.

Therefore equipment such as motors, exposed transformers windings, and the likes must be overhauled and rewound at nearly the cost of new equipment or scraped and new equipemnt purchased. Cables must be totally scraped. Bus bars and other non insulated items can be clean with large amounts of warwm fresh water and then can be reused without problem. Switchgear, breakers, and the likes must be completely cleaned and overhauled with new and refurbished components under supervision of the equipment vendor or new equipment purchased.

Which ever route you take, restore or purchase new, it is strongly recommended that the safety and reliability of the electrical systems be of the higest concern with due consideration to all of the obvious economics issues.