Imagination at work Ground Fault Circuit Interrupters Jonathan Potter GE Energy Management Industrial Solutions

Purpose of GFCI’s GFCI devices protect people from hazardous electric shock Listed to UL 943 Breakers also comply with UL GE Industrial Solutions | November 2014

Electrocutions Associated With Consumer Products (US Data) 3 GE Industrial Solutions | November 2014

Basic Concepts Ground Fault / Residual Current Electric current that flows from electrical equipment through a human to ground. Terms used: UL 943:ground fault current IEC:residual current Potential causes: Insulation fault in the equipment. Wiring fault in the equipment or installation. Current from equipment to earth in absence of fault. 4 GE Industrial Solutions | November 2014

GFCI/RCD Technology VOLTAGE DEPENDENT (VD) Device with electronic detection, evaluation and/or interruption functions, that is dependent on line supply voltage Differential current detection typically by current transformer Current interruption by electromagnetic mechanism with electrical contacts. VOLTAGE INDEPENDENT (VI) Electromechanical device in which neither detection, evaluation nor interruption depend on line supply voltage Differential current detection and energy for operation typically by current transformer 5 GE Industrial Solutions | November 2014

Benefits of Voltage Dependent technology Electronics provide features not generally available to Voltage Independent devices : Higher detection sensitivity –VD devices: max 6 mA - threshold for “let-go” current (UL 943) –VI devices: min 20 mA - threshold current for ventricular fibrillation, require special manufacturing techniques 6 GE Industrial Solutions | November 2014

Benefits of Voltage Dependent technology End of life indication UL 943 specifies that GFCIs at end of life shall, upon conducting an internal test, either: – a) provide an indication that the device needs replacing, or – b) make the device unable to deliver power. 7 GE Industrial Solutions | November 2014

1 mA Current Level (Milliamperes) 5 mA 6-16 mA mA mA > 2000 mA Perception level. Slight tingling sensation. Slight shock felt; not painful but disturbing. Average individual can let go. However, strong involuntary reactions to shocks in this range may lead to injuries. Painful shock, begin to lose muscular control. Commonly referred to as the freezing current or "let-go" range. Extreme pain, respiratory arrest, severe muscular contractions. Individual cannot let go. Death is possible. Ventricular fibrillation (uneven, uncoordinated pumping of the heart.) Muscular contraction and nerve damage begins to occur. Death is likely. Cardiac arrest, internal organ damage, and severe burns. Death is probable. Probable Effect on Humans Benefits of Voltage Dependent technology 8 GE Industrial Solutions | November 2014 VDVI >20mA gap References NIOSH [1998]. Worker Deaths by Electrocution; A Summary of NIOSH Surveillance and Investigative Findings. Ohio: US Heath and Human Services. Greenwald EK [1991]. Electrical Hazards and Accidents - Their Cause and Prevention. New York: Van Nostrand Reinhold.

Load IIn IOut If the current out = current back, the differential current transformer shows no output. L N Differential Current Transformer Current “Adding Machine” How GFCI’s work GE Industrial Solutions | November 2014

How GFCI’s work Current “Adding Machine” 240V Load IIN IOut L1L1 L2L2 N 120/240V Load IIN IOut L1L1 L2L2 Differential Current Transformer GE Industrial Solutions | November 2014

Current “Adding Machine” Under Ground Fault Conditions Load IIn = 6A IOut = 5.9A Ground-Fault.1A L N Differential Current Transformer If I-out does not equal I-in, the differential current transformer creates an output signal. How GFCI’s work GE Industrial Solutions | November 2014

GFCI location requirements per US National Electric Code 2014 In general, GFCI devices are required in wet locations Bathrooms, Garages, Outdoors, Unfinished basements Kitchens near countertops Sinks – Where receptacles are installed close to the sink Bathtubs or shower stalls - where receptacles are installed close to the shower stall or tub Laundry areas Boathouses Dishwashers And other locations… 12 GE Industrial Solutions | November 2014

Questions??? 13 GE Industrial Solutions | November 2014