Power disruptions can cost businesses hundreds of thousands or millions of dollars. Devices that correct or eliminate power quality issues like sags, swells, and transients are important to reduce costs. Power quality issues are caused by events on the utility grid or within a facility. Proper protection devices and backup power sources can help mitigate these issues and improve equipment performance. A study estimated that power interruptions cost the US economy $80 billion annually, with most of the costs borne by commercial and industrial sectors due to downtime of electronic equipment.

2. Power disruptions can cost hundreds of thousands - or even millions of dollars in lost production, clean-up and start-up costs. Few industrial or commercial operations are immune to the costs of power problems, making devices that correct for or eliminate these problems an economic imperative.

3. Any occurrence, manifested in voltage, current, or frequency deviations which results in failure or misoperation of customer end-use equipment

4. The integration of electronic equipment into everyday life has raised the bar substantially!

5. Power Quality can be subdivided into Temporary Conditions Transients Sags & Swells (0.5 Cycles – 1 minute) Long Term Voltage Variations (> 1 minute) Flicker Stead-State Conditions Harmonics Voltage & Frequency Stability

7. Causes of: Grid Switching (Utility) Load Switching (In-Plant) * Lightning Transformer Inrush * Load switching accounts for 85% of all transients

8. Solutions for: Inductors “ Smart” Switching techniques (zero crossing) Transient Voltage Surge Suppression

9. Causes of Sags Loose wiring Faults Motor starts VR failures Lightning Equipment Failure 33% Sag for 12.2 Milliseconds

10. Service Entrance Gear Utility Source A B C fault

11. Causes of Swells: Faulty equipment (i.e. regulators & load-tap changers) Capacitors 67% Swell for 26.1 Milliseconds

12. Causes of: Storms Ice Animals Failed equipment

13. Power Reliability is a statistical measure of the number, frequency and duration of power disruptions Sags, Swells and even Momentary events are not factored into Reliability calculations Most Utilities maintain an acceptable level Reliability as required by their local utility board

14. Source: EPRI, An Assessment of Distribution System Power Quality, Vol. 2: Statistical Summary Report. Palo Alto, CA. EPRI TR-106294-V2 (May 1996)

16. Device % Nominal Voltage Ride-Through Time Contactors 43-49% 2 cycles Relays 78% < 1 cycle DC Power Supplies 70% 9.2 cycles PLC’s 47% 37 cycles Regulating Ballasts 65% Varies ASD’s 70% 2 cycles

17. Defining your level of sensitivity Outage (5 minutes+) Momentary (2 seconds to 5 minutes) “ Blips” (< 2 seconds) Picking the correct solution Includes an evaluation of cost, space, personnel, safety, etc

18. Berkeley Lab Study Estimates $80 Billion Annual Cost of Power Interruptions (February 2, 2005) $57 billion (73 percent) is from Commercial Sector and $20 billion (25 percent) in the Industrial Sector Momentary interruptions were responsible for two-thirds of the cost, at $52 billion “ This finding underscores that fact that, for many commercial and industrial customers, it is the length of the ‘down-time’ resulting from a loss of power that determines the cost of interruption, not necessarily the length of interruption itself,” Source: Understanding the Cost of Power Interruptions to U.S. Electricity Consumers

19. Local protection (sags and outages) Sectionalize (outages) Install arresters (transient protection) Expedite protection equipment (sags) Regular maintenance (outages) Backup generation or 2 nd Utility source (outages)

20. Device Possible Solution Result Contactors & Relays Hold-in Circuit Improved performance up to 75% Sags PLC’s PQ Resistant Programming Improved performance up to protection limits ASD Local Ride-Thru Device Improved performance up to 60 % Sags UPS Local Ride-Thru Device Full sag protection

21. One PD for each XFMR One PD for 3 XFRM’s A B C fault

22. “ Facilities housing electronic load equipment of any type should have service entrances equipped with effective lightning protection in the form of Category “C” surge protective devices, as specified in IEEE Std C62.41.1&.2-2002” In addition, “It is recommended that additional surge protective devices of Category “B” or Category “A”, as specified in IEEE Std C62.41.1&.2-2002 be applied to downstream electrical switchboards and panel boards , and panel boards on the secondary of separately derived systems.”

23. Want the device closest to the fault to operate as quickly as possible Want to avoid miss-coordination Fuses will operate in ½ cycle vs. 3-5 cycles for breakers A B C fault

24. Critical Load Utility Input Output Input Bypass PES Isolation transformer Up to (4) power modules System control AC caps Battery Battery charger AC inverter

25. Voltage Sag red = supply voltage; blue = load voltage

26. Critical load Output Input Bypass Main container Isolation transformer Up to (8) power modules Battery New or existing back-up generator system Utility input AC gen Diesel, Natural Gas or Turbine Engine Diesel engine Power- Electronic Switch Battery charger AC inverter System control AC caps Transfer switch