Selecting Surge Protection Devices For Reliable Power Distribution

In today’s world of technology, it is crucial to have a reliable power supply. Almost every electrical device, whether in commercial and industrial properties or residential buildings, relies on reliable, uninterrupted power. A sudden surge in power can cause costly equipment damage, disruption of critical operations, or significant downtime. Surge Protection Devices, or SPDs, can be used to protect against this. SPDs prevent costly system damage by diverting and limiting excessive electrical flows. In this article, we will examine key considerations when choosing SPDs to ensure reliable distribution of power. You’ll learn how partnering with an electrical utility equipment service company can help you make the right choices for your particular needs.

1. Understanding Surge Protection Devices

Surge Protection Devices work by detecting and diverting excessive voltage to the ground or another safe pathway, preventing the surge from traveling downstream and damaging sensitive electronics. SPDs prevent surges by detecting excessive voltage and diverting it to the ground or another safe path.

Primary Functions Of SPDs:

  1. Clamping Voltage: Reduces surge voltages.
  2. Protecting insulation and components: Preventing overheating or breakdown of internal wiring.

2. Common Causes of Power Surges

It’s important to understand voltage surges and their causes before you choose a SPD.

  1. Thunder: A direct hit can produce massive transient currents within a power distribution system. Even indirect strikes can lead to damaging surges.
  2. Switching Utility: Utilities are known to switch grids or reroute energy, which causes voltage spikes that can be brief and significant.
  3. Internal Electrical Events: Large motors and HVAC systems cycling on and off create localized surges.
  4. Faults: Electrical short circuits or faults can cause sudden, large fluctuations in voltage.

Different SPDs have different ratings for handling surge levels. Recognizing your site’s likely surge source will guide you in the selection process.

3. Types of SPDs and Their Applications

Surge Protection Devices are generally classified as Type 1, 2, and 3 (though names can vary according to region and standards). Understanding these categories will help you deploy multi-layered protective measures:

  1. Type 2 (Service Entrance SPDs)
  • These devices can be installed at either the main electrical panel or the service entrance. They protect against external sources like lightning strikes.
  • They are often the primary line of defense.
  1. Type 2 (Distribution Panel SPDs)
    • Installed below the main service panel, for instance, in sub-panels.
    • Type 2 devices protect against residual surges, which are not detected by Type 1, as well as internal surges within the facility.
  2. Type 3 (Point of use SPDs)
    • The surge protector can be found where the equipment is attached to the power source (e.g., Power strips, device-level surge protectors).
    • Provide excellent protection for electronic equipment by clamping low-level surges.

In most cases, the best approach is a coordinated layering of surge protection, which is often referred to as “zoned” surge protection. A robust surge protection system could include Type 1 SPDs in the main panel and Type 2 SPDs in secondary panels. Type 3 SPDs would be installed on critical or sensitive equipment.

4. Important Selection Criteria

When selecting SPDs, take into consideration the following factors for effective surge protection.

  1. Surge Capacities (kA Ratings)
  • The kA ratings indicate how much surge can be safely handled by the SPD without failure. A higher kA may be required for facilities in areas susceptible to heavy electrical storms and lightning.
  1. Voltage Protection Rated (VPR)
    • VPR measures the clamping current under surge conditions. Lower VPRs usually mean better protection of sensitive equipment.
  2. System Voltage
    • Make sure the SPD matches the voltage configuration of your facility (single-phase or three-phase) and grounding scheme.
  3. Replaceable vs. Non-Replaceable Modules
    • Some SPDs will allow you to change modules after they have been exposed to a surge. This allows for long-term savings and can minimize downtime.

Conclusion

Surge Protection Systems are fundamental to a reliable power distribution system. Many and sometimes unpredictable power surges can occur due to lightning, utility switching, or internal electrical events. Understanding SPDs, the selection criteria, and the importance of installation will help you reduce the chance of power surges causing damage. A trusted electrical utility equipment service will tailor your surge protection to your unique needs and maintain it over time. Investing in the right SPDs can not only provide peace of mind but also safeguard your equipment.