1. Ground Fault Protection Overview April 2008

2. Ground faults occur in electrical systems where you are likely to find moisture, dust, vibration, and/or corrosive chemicals. Ground faults represents a danger to workers through electrical shock and arc-flash. Ground faults can cause fires, explosions, and system interruptions. Equipment Ground Faults Source: FM Global

3. Ground Fault Detection & Prevention • 90% of ground faults occur over time and can be prevented by monitoring. • Fuses and circuit breakers do not protect against ground fault incidents. • Ground fault monitors and relays improve the safety of your workers. • Ground fault detection devices must protect to a safe level without causing nuisance trips which impact the uptime of an industrial system.

4. POWR-GARD Ground Fault Protection • RCD Series detects leakage current from 10mA to 3A with variable time settings for alarm or response • GFR Series provides leakage current detection with additional motor protection to prevent motor restart in fault condition • Both products work with WKE Series current transformers, uniquely designed for interface with POWR-GARD relays to assure protection without nuisance tripping

5. Earth Loop Monitor • ELM Series - Ground Continuity monitor • Assures proper safety grounding of portable or mobile equipment • Used in applications where having a proper ground circuit is critical • Particularly used where subject to water, dust, and vibration • Alarm range 1.0 Ω

6. Ground Fault Relays RCD300M2 24V or 120V GF Test button Leakage current options Relay “ON” indicator Current selection dial Fault indicator light Response time select dial

7. Ground Fault Monitors GF Test button Relay “ON” indicator Leakage current options GF Test Reset Button Fault indicator light Current selection dial Insulation Resistance Time selection dial

8. Device Selection * All devices must be used in conjunction with WKE series current transformers.

9. Accessories

10. Littelfuse Product Benefits • Protects circuits in ungrounded, grounded or high resistance ground systems • Protects workers to a lower level of leakage current for added safety • Provides reliable protection without nuisance tripping which improves system availability • Offers metering output to drive a remote meter or interface • Predictive protection reduces incidents of arc-flash, fire and system disruption

11. Industries Using Ground Fault Protection • Ground Fault Protection is likely to be used by industries where electrical systems are exposed to moisture (water), dust, vibration and/or corrosive chemicals. • Semiconductor manufacturing - Power pedestals for RV’s • Mining Industry - Marinas and boat houses • Petrochemical - Equipment for carnivals, fairs, • Pulp and Paper and outdoor entertainment • Pharmaceutical - Pools, spas and water parks • Municipal water treatment plants • POWR-GARD ground fault protection products have an advantage over competitive products as they are designed to prevent nuisance tripping caused by line noise, and therefore can be set to a more sensitive level to increase protection without impacting uptime of critical systems.