Why Power Outages Cause Equipment Failure — And How to Prevent It
Key Takeaways
Power restoration after outages creates destructive transient overvoltage events, including high-frequency ringing that generic surge protectors often fail to fully mitigate.
Transient overvoltage leads to immediate failures or gradual degradation, contributing to shortened equipment life and costly unplanned downtime—implicated in up to 98% of electronic failures.
Single-point protection is insufficient. A cascaded surge protective device (SPD) strategy is required to progressively reduce transient overvoltage energy and protect loads throughout the electrical distribution system.
Uninterruptible Power Supplies (UPS) and generators are complementary, not substitutes for surge protection. UPS systems manage interruptions and voltage regulation, while SPDs mitigate transient overvoltage; both are necessary.
Introduction
Power outages don’t just interrupt operations — they can trigger transient overvoltage events that damage and/or destroy equipment, and cause equipment malfunctions. Understanding why this happens and how to prevent it is critical for reliability, uptime, and safeguarding sensitive assets.
Many facilities operate in a constant state of risk: frequent equipment failures, escalating repair costs, and disrupted production from power anomalies. Nearly nine out of 10 global executives report energy-related disruptions as a top operational concern, with transient overvoltage driving massive downtime and expenses.
What Happens During A Power Outage
When utility power is lost — whether from a storm, grid fault, or equipment failure — voltage abruptly drops. That’s the outage itself. However, the risk to equipment does not just come from the outage, but from what follows when power returns.
Restoration causes transient overvoltage. When circuits re-energize, transient overvoltage is created, increasing voltage and unleashing “a high frequency ringing on top of the 60-Hz power frequency.”² This increase in voltage doesn’t just spike once and disappear; it often oscillates rapidly, swinging above and below the normal voltage level in a “ringing” or ripple pattern before settling down.
The frequency of this oscillation can be very high, ranging from kilohertz to megahertz, much higher than the standard 60-Hz power frequency.
The rapid high-frequency ringing is often amplified by automatic circuit reclosers (ACRs) used by utilities. ACRs also create repeated transient overvoltage events; the mechanical operation to restore power following a temporary fault inherently generates new, momentary surges each time it engages.³
What Is Transient Overvoltage and Why Is It Harmful?
Transient overvoltages (also referred to as transient voltages, power surges, or spikes) increase voltage by thousands of volts in nanoseconds, causing outright destruction or latent stress that accelerates equipment aging.
A common, yet unpredictable anomaly, transient overvoltage’s causes include lightning, switching operations within the grid, electrical load changes, inductive kickback from motors and transformers, system faults (e.g., short circuits), and even electrostatic discharge. The National Electrical Manufacturers Association (NEMA) estimates 60% to 80% of transient voltage events are caused by internal facility events, like load switching.
Despite their short duration, the magnitude of transient overvoltage events stress insulation and electronic components, leading to immediate failure, or latent damage that shortens equipment lifespan.¹
Components often affected include:
- Microprocessors and power supplies: High voltage can puncture junctions or destroy chips.
- Conductor insulation, motor windings, and transformers: Insulation damage accelerates aging and can cause catastrophic failure.
Transient overvoltage damages equipment if no immediate failure is visible.
How to Prevent Equipment Failure from Power Outages
Mitigating the impact of outages requires a multi-pronged approach:
1. Cascaded Surge Protection
Surge Protective Devices (SPDs) — also referred to as Transient Voltage Surge Suppressors (TVSS) — are the first line of defense, absorbing excessive voltage during transient voltage events. Placing a single SPD at the main panel is most often insufficient; a cascading SPD strategy reduces the magnitude of residual transient energy reaching equipment.
2. Generators & Power Continuity Planning
For prolonged outages, backup generation ensures continuity. However, generators should be integrated with Automatic Transfer Switches (ATS) protected by surge mitigation, including at the control voltage to prevent harmful switching transients during transfer functions.
3. Uninterruptible Power Supplies (UPS)
UPS systems provide backup power during outages, protecting against brief interruptions. Some also offer voltage regulation, smoothing sags and swells before they reach equipment. UPS can bridge the gap between outage and generator readiness, eliminating transfer spikes and reducing stress on loads.
Note: UPS devices do not replace SPDs — they complement them. Surge protection should be upstream of UPS inputs to shield the UPS itself and downstream equipment.⁴ Some argue that a double conversion UPS can mitigate transient overvoltage events downstream; however, they can be cost-prohibitive, often costing more than the alternative of surge mitigation.
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Conclusion
As facilities grow more reliant on sensitive electronics, power anomalies represent an escalating threat with real financial and operational consequences. Generic SPDs and incomplete strategies leave critical gaps. According to a recent Prologis supply chain outlook, nearly nine out of 10 global executives reported energy-related disruptions in the past year, with many identifying power reliability as a top operational risk. This reflects a broader trend: as facilities become more digital and dependent on sensitive electronics, even brief power anomalies can become major operational failures. By understanding the causes and implementing tiered surge protection, backed-up generation, and UPS systems, organizations can greatly reduce damage risk, protect sensitive electronics, and improve resilience against disruptions.
Maxivolt combines advanced technology (non-ground-dependent, redundant, precisely engineered) with tailored cascaded application and proven expertise to deliver comprehensive, quantifiable protection.
Resources
1. Electrical Overvoltage: What It Is, Main Causes, and How to Prevent It. (2025, July 22). Solera.com. Retrieved December 22, 2025, from https://www.psolera.com/en/news/electrical-overvoltage-what-it-is-and-causes?
2. T&D System Design and Construction for Enhanced Reliability and Power Quality. EPRI, Palo Alto, CA: 2006. 1010192.
3. What is Auto Recloser: Working Principle, Types & Functions. (2025, November 6). Liyond. Retrieved December 31, 2025, from https://www.liyond.com/blog/what-is-automatic-circuit-recloser-principle-types-and-functions/
4. Protecting an Uninterruptible Power supply (UPS). (2021, November 30). ALLTEC’s. Retrieved December 31, 2025, from https://alltecglobal.com/importance-spd-protecting-uninterruptible-power-supply-ups/
