When Wet Really Isn't Wet (part 2)

Albert M. Rose, P.E.

In our last post we discussed equipment ratings and location definitions (what is a dry or wet location).  In this post let's discuss equipment that is not made to get wet, yet for some reason it does.  Does this mean it needs to be thrown away and a new one purchased?  No, of course not.  I spilled a diet soda on the keyboard of my computer a few years ago.  After the panic lessened I realized it was still working.  So the computer was sent to a computer shop, a new keyboard was installed, and the computer still works to this day.  However, that doesn't mean that anything that gets wet can be fixed.

First, let's discuss electrical distribution equipment.  Things like circuit breakers, switchgear, and control panels.  Recall from our first post that while pure water is not conductive, it does become conductive when chemicals and normal impurities are mixed in.  So any water from your tap would be conductive, as would water from a fire protection system, or water as a result of rain.   

Let's say there is a leak in an electrical room and some switchgear gets wet.  Is it panic time?  First, you have to examine WHERE the water went.  If the water just was on the external enclosure and did not penetrate into the internal sections then, no, it's not panic time.  Most switchgear is rated as NEMA 12 enclosures, which will allow for a light spray of water.  However, what if the water penetrated and got into the bus bars and circuit breakers.  Is it a problem then?  The short answer is yes.  Water that gets on exposed electrical connections, whether its bus bar connections or in circuit breakers, starts the corrosion process almost immediately, which can destroy connection integrity.  This loss of integrity can result in high-resistance connections that will then overheat and fail.  While the connections can be cleaned, tested and re-certified, sometimes the cost to do this is more than the cost to just buy new switchgear.  So the determination will need to be done on a case-by-case basis.

But what about electronics, like the aforementioned computer?  There are companies that specialize in cleaning and decontaminating electronics.  And most can do the job for less than the cost of buying new, and in fact many now offer warranties of anywhere from three months to a year.  As an example, a call center had a small fire, and their electronic communications and servers got wet from the fire fighting activities.  The cost estimate to replace all of their equipment, which was over 10 years old, was over $500,000.  An electronic cleaning company was contacted, and they quoted a cost of less than $25,000 to clean all of the electronics, and they offered a one year warranty that the electronics would not fail as a result of the water intrusion.  That's a big cost savings with an added new warranty the equipment didn't have before it got wet!

So, what happens with the Authority Having Jurisdiction (AHJ), commonly called the Fire Marshal or Building Inspector, gets involved?  Stay tuned for Part III.