Print Page   |   Contact Us   |   Sign In   |   Join
IAEI Magazine | Author: Cari Williamette
Share |

Cari Williamette

Cari Williamette is the senior electrical inspector for the city of St. Paul, Minnesota. She also teaches code classes for IBEW LU 343 and LU 110. Cari is an alternate on CMP-19, representing IAEI. Previously, she spent six years as an electrical contractor in southern Minnesota, specializing in industrial and agricultural installations, and seven years as electrical inspector for several jurisdictions in Minnesota. She has served one term as president of the Minnesota Chapter, IAEI, and on the electrical committee for the Minnesota Building Official’s Institute for the last five years.


Ground-Fault Protection for Marinas and Boatyards

Two young boys are excited about being at the lake for the first time that summer. While the parents unload the car, they quickly don their swimsuits and run down the dock. The first boy dives in, oblivious to the cold water. The second boy stops to consider if he should dive in also, or wade in slowly. Suddenly the first boy screams, begins thrashing in the water, and goes under. His friend dives in after him, feels the electric current flow through his body, causing his muscles to contract. He can’t force his body to swim, or even to stand up. He also goes under. By the time the parents can get to the dock, both boys are dead. While this particular scenario is fictitious, electric shock drowning happens far too often.

GFCIs and Electrocution

"According to Acting Chairman Anne Graham of the U. S. Consumer Product Safety Commission, "The GFCI shock protector constantly monitors electricity flowing through a circuit. If the hair dryer or any electric appliance accidentally topples into the sink or tub, the GFCI will shut down the power in milliseconds to protect the consumer against electrocution or severe electrical burn injuries.” (CPSC News release, October 18, 1989). But do GFCIs actually protect people from electrocution? GFCIs measure the current flow on the "hot” conductor and compare it to the current flow on the "neutral” conductor. If the GFCI detects more than 5 – 7 milliamperes of difference, it will shut off the circuit.