SurgeCalc^TM is designed to suggest an adequate level of TVSS protection based on the IEEE-C62.41 Category/Exposure Level as well as the facilities actual operating environment.

1. Geographic location of the facility.

This can be determined by consulting an Isokeuronic map and finding the location of the facility. The Iso map will show the number of days lightning is experienced for any given location. Once this is done, using the IEEE classification, rate the location for high, medium, or low exposure.

High Medium Low

2. Facility location relative to other buildings.

If the facility is in a rural location isolated from other structures, or on a hilltop the probability of a lightning induced transient is much higher than in an urban environment.

Rural Suburban Urban

3. Adjacent Structures.

If the facility has a large antenna, water tower, or is the tallest building in the area it has a higher probability than a facility nestled among other structures.

Tallest Equal Smallest

4. Location of the facility on the utility service.

If the facility is on the end of the utility line transients will travel down the transmission line, or if there are other large industrials on the same line transients could be introduced on the line by these other facilities.

End-of-Line Multiple Clients Dedicated Line

5. Utility history for an existing facility or for facilities being served by the same utility of a planned facility.

If there has been equipment disruption or equipment damage in an existing facility this is an indication of a high probability of transient activity. If this is a new facility, an inquiry to other facilities served by the same utility will give an indication of transient activity.

Damage Has Occured Restarts Required Few Disturbances

6. Consideration of the equipment being protected and the function this equipment performs as it applies to the facility mission.

If the equipment is supporting mission critical functions such as an on-line database, a continuous process control application, life support equipment, or other equipment that is essential for the operation of the facility it should have a high level of protection.

Must Not be Down Loss of Revenue Recoverable

7. Expense to repair equipment.

If there is equipment within the facility that is very expensive to repair if damaged, such as MRI equipment, network controllers, CNC machinery etc. the level of protection should be high to avoid expensive repair bills.

Expensive Moderate Inexpensive

IEEE C62.41 Category: Category C Category B Category A

Recommended Products and Critical Specifications

IEEE C62.41

Facility Exposure (Application Level)

Calculated Exposure Index