Surge protection devices limit the magnitude of overvoltage transients to prevent equipment damage. While the cause and prevention of surges have been known for some time, the proliferation of semiconductor devices in recent years has made SPDs a necessity in industrial facilities.
Surge protection includes:
- Protection inside the facility and out – at the main circuit breaker and at specific sensitive equipment
- Comprehensive low-resistance grounding – surge protection is not complete without this
- Data line and power protection – surges can damage multiple types of equipment
- Comprehensive surge protection approach is the best strategy.
Basic three points need to be considered while planning to install a surge protection system:
1. Risk analysis according to national and international standards – careful and systematic risk assessment needs to be carried out after inspection of the physical structure and electrical installation. This assessment addresses the various sources of damage (direct lightning strike, transient overvoltage, etc), financial losses and the cost evaluation of planning, installing and maintaining a surge protection system.
2. Characteristics of the area to be protected – in order to ensure total protection of a physical structure from the effects of lightning strikes and surge voltage, various protective measures, and equipment that is tailored to one another are required. To ensure proper protection IEC divides the area of protection into different zones. Such as, the unprotected zone outside the building where direct lightning strikes are possible, zone outside the building that is protected by LPS via air terminals, zone inside the building where high energy surge voltage is expected, and zone inside the building where surge currents are expected to be extremely low.
3. Surge protection device types – surge protection power values are based on the protection class to be achieved. For example, Facility Guards will be required to protect the zone outside the building while Transient Limiters and Hybrid Surge protectors for data and telecom application will be efficient within the building where high energy surge voltage is expected.
Conclusion
Risk assessment, in general, is a complicated and demanding process but is still advisable. With the risk assessment report in hand, the type of SPDs best suited for your facility can be considered.
Taking a holistic approach to industrial surge protection is the most appropriate way to minimize the risk and its potential impact.
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