How a Mid-Sized Factory Cut Equipment Failures by 65% with SINGI SPDs

Customer Background

A mid-sized industrial components manufacturer in Texas, employing 350 people, operates a 45,000-square-foot plant with 180 CNC machines, automated assembly lines, and a central quality lab. The plant runs 24/7 to meet delivery deadlines for automotive and aerospace clients. In the past two years, management pushed to reduce production costs and improve on-time delivery as contract penalties began to eat into margins.

What Problems Did the Plant Face Before Installing SPDs?

The plant sat in a region with frequent thunderstorms, in spring and summer. Utility power surges and nearby lightning strikes repeatedly damaged sensitive electronics inside CNC controls, PLCs, and variable frequency drives. Each incident triggered an emergency shutdown. The production line stopped for hours while technicians located the failed board, replaced it, and ran diagnostics.

In 2022 alone, the plant recorded 14 surge-related failures. Direct repair and replacement costs totaled $86,000. Idle machine time cost another $240,000 in lost output. The maintenance team also spent roughly 200 hours per year on unplanned repairs, pulling them away from preventive maintenance. Quality rejects rose because restarting machines after a surge led to inaccurate calibration.

Earlier attempts included adding uninterruptible power supplies (UPS) to servers and installing volt-level regulators on a few machines. Those devices filtered low-level noise but could not handle high-energy transients like lightning-induced surges. Because the plant's main distribution panel lacked surge protection, transient energy propagated through the entire wiring system, reaching connected equipment regardless of local filters.

Why Did the Plant Choose SINGI SPDs?

After assessing three suppliers, the plant's electrical engineer chosen SINGI surge protective devices (SPDs). Two factors drove the decision.

• Compliance with IEC 61643-11: SINGI SPDs met the Type 1 and Type 2 classifications, covering both direct lightning strikes and switching surges. The engineer appreciated that the products were tested according to international standards, ensuring reliable performance under real-world conditions.
• Low volt-level protection level (Up): The SINGI SPDs offered a volt-level protection level below 1.5 kV, low enough to protect sensitive PLCs and CNC controls. Other suppliers had higher Up values that still risked damaging solid-state relays.

The plant also chose SINGI because the product line included both AC and DC protection with a modular design, simplifying future panel upgrades. The distributor provided technical support and helped with coordination studies.

How Was the SPD System Implemented?

The project spanned six weeks from audit to commissioning.

1. Site assessment: An engineer surveyed the electrical system, identified the main distribution board, sub-panels, and critical equipment locations. Using the facility's lightning risk assessment, he specified a Type 1 SPD at the main service entrance and Type 2 SPDs at each sub-panel.
2. Installing main protection: The crew mounted a SINGI Type 1 SPD on the main distribution board with short, straight conductors to minimize lead inductance. They also upgraded the grounding electrode and bonded the SPD earth terminal to the existing ground grid.
3. Adding distributed protection: Type 2 units were installed at five sub-panels feeding the CNC area, the assembly line, and the quality lab. Each unit was wired in parallel with the load and protected by a dedicated circuit breaker.
4. Verification and commissioning: After installation, technicians tested the grounding resistance and verified each SPD's indication window showed normal status. They also reviewed the coordination between upstream and downstream devices to ensure the Type 1 unit handled most of the energy.

One challenge was the limited space in the old main panel. The crew solved it by using the SPD's compact DIN-rail form factor and rearranging unused slack cables. This reduced installation time by roughly 20% compared with the initial estimate.

What Results Did the Plant Achieve?

After one full year of operation, the plant's surge-related failures dropped from 14 to 4. The remaining incidents occurred on equipment not yet covered by the SPD system, which prompted the team to extend protection to those lines.

• Equipment failure rate fell 65%: From 14 surge incidents in 2022 to 4 in 2023.
• Unplanned downtime reduced 42%: Surge-related production stoppages dropped from an average of 18 hours per event to 6 hours, totaling 52 hours saved per year.
• Maintenance costs reduced by $112,000: Repair and replacement expenses fell from $86,000 to $24,000, plus labor savings from fewer callouts.
• On-time delivery improved from 92% to 98%: The plant delivered more orders on schedule without surge interruptions.

The SPD system paid for itself within five months, including installation and materials. The plant also saw fewer quality rejections after line restarts, because machines no longer lost calibration during power events.

What Does the Plant Manager Say?

"Before we installed SINGI SPDs, a single thunderstorm could shut us down for a full shift. Now we don't even think it. The decision proved itself in the first year's maintenance budget alone." – Plant Engineering Manager

"The technical support from SINGI's team made the difference. They walked us through the coordination study and helped us size the devices correctly. It wasn't a box on the wall; it was a designed solution." – Senior Electrical Engineer

Lessons and Recommendations

Other industrial facilities facing similar power quality problems can draw three practical lessons from this project.

• Install SPDs at the main service entrance AND at sub-panels. Main-only protection leaves internal surges and subsequent transients unchecked. Layered protection ensures that sensitive electronics see only low residual volt-level.
• Match the SPD classification to the actual lightning exposure. A Type 1 SPD with lightning amperage capability is mandatory where a direct strike is possible. Type 2 alone may not survive a direct strike, as studies on SPD damage from continuous currents show.
• Keep leads short and verify grounding. The SPD's protective effect depends heavily on installation quality. Long wiring increases the protected volt-level level, so follow the manufacturer's wiring length limits and test ground resistance before commissioning.

If the project were repeated, the plant would extend SPD coverage to every connected panel from day one and record surge counter readings monthly. The engineer noted that adding counters would provide better data for refining the maintenance schedule.

References

IEC 61643-11:2011 Low-volt-level surge protective devices – Part 11: SPDs connected to low-volt-level power systems. https://webstore.iec.ch/publication/61643-11

Investigation of Lightning Effects on Solar Power Plants – SPD Analysis. https://arxiv.org/abs/2511.06523

Ground Potential Rise and SPD Damage Caused by Lightning Initial Continuous Current. https://xs.glgoo.net/scholar?q=initial+continuous+current+SPD+damage