Mitigating Hazards for Data Center Transformer Switching

The Challenge: Frequent Operations, Persistent Risk

Pad-mounted transformer (PMT) switching isn’t a rare event. At large facilities, it happens routinely throughout the year as part of:

• Preventive maintenance programs
• Redundancy and failover testing
• Fault isolation and rapid response

Each of these operations requires interaction with energized equipment. And every interaction introduces risk, particularly when it involves opening low-voltage (LV) or medium-voltage (MV) compartment doors. Traditionally, safety measures have focused on limiting that risk. Personal protective equipment (PPE), procedures, and arc flash boundaries are important, yes, but still centered on protecting workers who remain within the hazard zone.

The Solution: Closed-Door, Remote Operation

For this project, CBS ArcSafe engineered a custom solution that allows operators to perform switching activities from up to 300 feet away with enclosure doors closed. At the center of this system is the RSK-PMT remote switching solution. With it, technicians can operate interior-mounted load interrupter switches from a safe distance. This isn’t just about convenience. It fundamentally changes the risk equation.

What makes this project stand out is how the solution was engineered to fit seamlessly into an existing system. The data center already relied on a Kirk-key interlock system and strict lockout/tagout (LOTO) protocols. Any viable solution had to:

• Maintain the integrity of the existing interlocking scheme
• Align with three internal two-position switches
• Ensure compliance with established safety procedures
• Eliminate the need to open LV or MV doors during operation

This wasn’t a plug-and-play scenario. It required a custom, closed-door design that integrated directly with the client’s infrastructure, all without introducing new risks or operational complexity.

A Shift in Safety Philosophy

This solution fundamentally shifts the approach from protecting workers in the hazard zone to removing them from the hazard altogether. Electrical safety has historically leaned heavily on administrative controls and PPE, but the hierarchy of controls tells a different story: The most effective safety strategy is to eliminate or engineer out the hazard whenever possible.

In this case, the hazard, proximity to energized equipment during switching, has effectively been removed from the equation. There are no open doors and no close-range interaction. The solution has been deployed across more than 200 transformers at the site. Importantly, it improves safety without slowing down the operation. In fact, it often improves responsiveness, especially during fault conditions where speed matters.

Where Safety and Efficiency Align

There’s a persistent misconception in industrial environments that safety improvements come at the cost of efficiency. This project proves the opposite. By enabling closed-door, remote switching:

• Safety is significantly improved
• Operational flexibility increases
• Downtime risk can be reduced through faster, safer response

At its core, this project reflects a broader belief: When risk cannot be eliminated outright, it can often be addressed through engineering and controls.

Not every facility will have identical constraints. Not every system will require the same level of customization. But the principle holds: If workers don’t need to be in the hazard zone, they shouldn’t be. And with the right approach, they often don’t have to be.