1. © 2001 POWERVAR, Inc.

2. POWERVAR Ground GuardTM A new solution for an old (and usually expensive) installation problem

3. POWERVAR Ground Guard b POWERVAR Ground Guard is a solution that makes it possible to eliminate the need for dedicated/isolated electrical circuits for sensitive electronic systems. b Ground Guard is based on patented POWERVAR technology. b Ground Guard power conditioning is paid for by savings in wiring costs.

4. © 2001 POWERVAR, Inc. Some History on Wiring b Many installation specifications continue to include dedicated/isolated electrical circuits out of habit. b Most of these specifications are based on inaccurate beliefs about the capabilities of dedicated/isolated electrical wiring. b Such special wiring techniques offer almost no protection for the system.

5. © 2001 POWERVAR, Inc. The definition..... A dedicated/isolated electrical circuit is one in which the circuit’s three conductors (hot, neutral, and ground) run continuously (with no splices) from a distribution panel with a neutral to ground bond (NEC defined newly derived source) directly to the protected load in a dedicated conduit and terminating in an approved isolated grounding (IG) receptacle.

6. © 2001 POWERVAR, Inc. This is a standard circuit

7. © 2001 POWERVAR, Inc. This circuit is dedicated/isolated G

8. © 2001 POWERVAR, Inc. Isolated Ground Receptacles b Dedicated/isolated circuits must be terminated in an isolated ground (IG) receptacle. b IG receptacles generally look like this. They are not like normal receptacles.

9. © 2001 POWERVAR, Inc. The non-isolated receptacle b Non-isolated receptacles are grounded via the mounting strap of the fixture. b There may be a separate ground wire or conduit may be used as ground. b The receptacle ground is common with other grounds.

10. © 2001 POWERVAR, Inc. The isolated (IG) receptacle b The ground of an isolated ground receptacle is only grounded via the dedicated/insulated grounding conductor. b Receptacle ground is not common with the conduit or other grounds.

11. © 2001 POWERVAR, Inc. Dedicated/isolated circuits b Must have their own hot, neutral, and insulated ground conductors, and... b Must be in their own conduit. b Must be terminated in an IG receptacle. b Must originate from a location with a neutral to ground bond (NEC defined “newly derived source” -- Paragraph 250-5D).

12. © 2001 POWERVAR, Inc. What do people believe...... ? b Dedicated/isolated circuits provide surge protection. b Dedicated/isolated circuits provide noise protection. b Dedicated/isolated circuits provide voltage regulation. b Dedicated circuits provide computer grade power.

13. © 2001 POWERVAR, Inc. Do you get surge protection ? b Because no other load shares the circuit, the computer is protected from transient voltages generated on its own circuit. b If transient voltages occur as a result of other loads connected to the same distribution panel, the dedicated/isolated circuit cannot prevent them from reaching the protected load.

14. © 2001 POWERVAR, Inc. Do you get noise protection ? b Because no other load shares the circuit, the computer is protected from electrical noise generated on its own circuit. b If electrical noise occurs as a result of other loads connected to the same distribution panel, the dedicated/isolated circuit cannot prevent these disturbances from reaching the protected load.

15. © 2001 POWERVAR, Inc. Do you get voltage regulation ? b Dedicated circuits do not regulate voltage (and the computer doesn’t need it). b Because no loads share the circuit, there are no other current demands that may cause voltage on the circuit to vary. However, if voltage levels vary at the distribution panel, they will vary at the load, too, even if the circuit is dedicated.

16. © 2001 POWERVAR, Inc. Computer grade power ? b Dedicated/isolated circuits have nothing to do with “computer grade power.” b Perhaps the reason dedicated/isolated circuits are popular is because we’ve used them since the days of the first computer. b Unfortunately, they are no longer adequate to protect today’s system topologies. b Do these circuits provide any benefit?

17. © 2001 POWERVAR, Inc. Yes -- but a questionable one b When a system is on a dedicated circuit, it is thought to be unlikely that someone will accidentally turn that circuit off. b This assumes that individual breakers in a panel are properly identified (something that should happen anyway). Dedicated circuits are expensive insurance against poor workmanship and panel maintenance.

18. © 2001 POWERVAR, Inc. Problems.... b Dedicated/islolated circuits are clean only to the extent that the distribution panel is clean. b Voltage regulation on a dedicated/isolated circuit is only as good as regulation at the distribution panel. b Dedicated/isolated circuits do not prevent or eliminate induced or radiated power disturbances.

19. © 2001 POWERVAR, Inc. Problems.... b Dedicated/isolated circuits do not protect systems from problems entering facilities from outside such as lightning. b Dedicated/isolated circuits are expensive, difficult to manage, impossible to maintain. b Electricians and inspectors often disagree on how to interpret wiring specifications. b And most importantly....

20. © 2001 POWERVAR, Inc. The biggest problem..... b Dedicated/isolated electrical circuits do not have the ability to prevent “ground loops” in today’s networked system environment. b Ground loops are the source of what one manufacturer calls “inter-system noise”. b Inter-system noise can destroy system hardware and disrupt system reliability.

21. © 2001 POWERVAR, Inc. What are “ground loops”? Courtesy of PowerCET Fig. 2 illustrates two circuits of different length. The safety ground at each receptacle will have a small voltage potential with reference to safety ground at the panel. These voltage potentials will be different because of the differences in circuit length and impedance (illustrated by the oscilloscope in the drawing). Connecting a data cable (white line) between the two computers powered by these circuits will create a “ground loop” in which noise currents will flow as a result of the voltage potential difference between the safety grounds of the two circuits. The “loop current” can induce disruptive disturbances into data lines.

22. © 2001 POWERVAR, Inc. Why worry about ground loops? Inside the data cable, the signal ground and/or frame ground conductor lies next to the signal conductors themselves for the entire length of the cable. The conductors can act like a transformer for an unwanted signal allowing a power disturbance in the ground to couple into the data circuit itself. Disruption of or damage to the system may occur. This may manifest itself as communication errors, I/O driver failures, or numerous unexplained network collisions and wasted system resources. Data terminal ready Modem ready Receive data Send data Signal Ground Typical RS232 Data Cable(example only)

23. © 2001 POWERVAR, Inc. Even ungrounded data cables b Networks using “differential” data pathways with unshielded data cable such as 10baseT ethernet will still experience problems. b In such installations the ground referenced offset voltages will be felt directly across the I/O port. If they exceed the port’s design limits, failure will occur.

24. © 2001 POWERVAR, Inc. Don’t power conditioners stop this? A power conditioner addresses normal mode noise and common mode noise. Ground loops are not the same thing. Traditional power conditioners should not be thought of as portable dedicated/isolated circuits. Safety ground is continuous. If data line grounds exist to other computers, a ground loop may still occur.

25. © 2001 POWERVAR, Inc. What about Ground Guard TM Data Cable Ground Ground Guard contains a specially engineered “ground conditioning filter” that prevents power disturbances from entering data cable grounding conductors or reaching I/O ports. The impedance is patented and safety agency approved. (UL, cUL, and VDE) Ground Guard completes the power conditioning picture by conditioning ground, too. Ground Guard does replace a dedicated/isolated circuit. Control Impedance

26. © 2001 POWERVAR, Inc. What are the benefits? b Elimination of dedicated/isolated wiring b No compliance problems with wiring codes b Elimination of the scheduling, time, hassles expense, and delays involved with using electrical contractors b Uniform installation environment b Portability - easy to remodel and rearrange

27. © 2001 POWERVAR, Inc. Other benefits.... b Grows with the system -- unlike wiring b Ground Guard is a hardware solution that can be leased. Electrical wiring cannot be leased. It’s cash out of pocket. b Ground Guard provides complete power conditioning, and since Ground Guard is paid for with resources that are normally spent on wiring, power protection is virtually free.

28. © 2001 POWERVAR, Inc. What do customers say? b “Our contractor estimated it would cost about $30,000 to rewire the place. The Ground Guard alternative was about $4500. »Grant DePorter, Managing Director, Harry Carey’s Restaurant b Thanks to POWERVAR’s Ground Guard power conditioners, we no longer worry about variations in local utility companies or electrical contractors. Ground Guard has made our power problems go away. It’s just that simple. »Craig K. Herzer, Manager of Info Systems, IHOP Corporation

29. © 2001 POWERVAR, Inc. What do customers say? b We’re very pleased to be associated with POWERVAR. The Ground Guard series of power conditioning products are a huge benefit to our customers because they provide a cost-effective method of helping to ensure reliable computer operation. As well, in cases where we retrofit an older POS system, the need to completely replace the existing wiring is eliminated. This is a considerable saving in both time and money. »Linda Gillis, Product Marketing Mgr., Squirrel Companies

30. © 2001 POWERVAR, Inc. Finally.... b Ground Guard is covered by POWERVAR’s five year warranty against defects in materials and workmanship. b Ground Guard is safety agency listed for use throughout the world.

31. © 2001 POWERVAR, Inc. b To learn more about Ground Guard, contact your POWERVAR representative or call POWERVAR at (800) 369-7179 b You may also learn more about Ground Guard by visiting us on the World Wide Web at http://www/powervar.com

32. © 2001 POWERVAR, Inc.