Disable Reclosing to Heighten Worker Protection

In utility line work, safety is built on layers. Each layer is essential; ideally, if one fails, another layer will prevent alignment of all the holes in James Reason’s proverbial Swiss cheese.

Recently, while preparing a training presentation focused on switching procedures, de-energization and grounding, I found myself thinking through the process backward and forward. I considered the moment a line is still energized, imagining the scenarios that could unfold for a troubleman or line crew. Then I thought forward again, this time to the crew working behind an open switch, between grounds and in an equipotential zone.

One question kept surfacing: If grounding is meant to protect us in the event of re-energization, why don’t we always disable reclosing on the circuit we’re working? OSHA requires blocking remote supervisory control during de-energized and grounded work, but disabling reclosing is not mandated. That’s a critical gap in our safety net.

A Hidden Risk
Automatic reclosing is designed to restore power after temporary faults, such as a tree brushing a line. But when a line is intentionally de-energized and grounded for maintenance, any re-energization attempt could be catastrophic. If reclosing is left enabled, the breaker will attempt to reclose multiple times – even into a grounded fault – before finally locking out.

With reclosing disabled, time delays are removed, even on the first relay. Here’s how it works:

• The breaker trips on the first fault, typically within three to eight cycles depending on settings and voltage.
• No reclosing attempts are made.
• The circuit locks out immediately and remains de-energized.

Immediate lockout significantly reduces the risk of unexpected re-energization and ensures the line stays safely out of service until it is manually restored.

Why Does This Matter for Workers?
Grounding is not a guarantee of safety during high-energy fault events. Reclosing into a grounded line can:

• Cause arcing, equipment damage and violent whipping of ground jumpers.
• Expose workers to dangerous step and touch potentials.
• Lead to failure of personal protective ground jumpers due to excessive fault energy.

The longer the system continues to reclose, the greater the energy delivered into the fault. This could exceed the capacity of protective grounds, leaving the line energized and workers exposed.

The Hazards of Multiple Reclosing Attempts
The first reclosing attempt typically uses a fast-acting protection curve to quickly clear transient faults. However, second and third attempts often rely on slower inverse time-delay curves, allowing more time for faults to clear naturally. This results in:

• Longer energized durations.
• Increased energy delivered into the fault.
• Greater arc flash risk.
• Elevated likelihood of ground jumper failure, which could result in the line remaining energized.
• Higher potential for injury or death.

Remember, reclosing’s job is to remove the fault. If the fault is a grounded line with personnel present, reclosing works against us – not for us.

Final Word
Workers are exposed to increased risk as repeated reclosing attempts lengthen time delays, making the act of disabling reclosing when working on grounded lines not just a best practice but a potentially lifesaving act.

About the Author: Ben Browne, CUSP, has over 20 years of global experience in electric utility safety, risk management and sustainability leadership. He currently serves as the safety and environmental manager for S&C Electric Co.