Worker Safety During a Power Outage

A power outage is a disruption of electrical service that creates elevated risk conditions for electrical and utility workers. There are heightened risks for worker safety when power is out compared to normal operations, including generator backfeed, islanding, urgent working conditions, poor weather, and unknown energy sources. These special hazards make proven safety procedures especially critical during an outage.

In this article, we’ll discuss outage-specific hazards that threaten worker safety, proven safety procedures for mitigating them, and the role of power restoration safety training.

Why Power Outages Increase Electrical Worker Risk

Power outages create unique hazards that do not exist during routine work.

There’s a tendency to make the false assumption that “no power means no danger,” which can cause individuals to overlook important safety precautions. In fact, power outages are more dangerous for workers than normal operations and must be treated as such.

There are many factors that contribute to heightened safety risks during an outage, including:

• Emergency Response Pressure: Workers may be under intense pressure to restore power in multiple locations, leading to rushed work and skipped precautions.
• Low Visibility: Since poor weather is one of the primary causes of power outages, the conditions outside are often suboptimal for hazardous work.
• Unpredictable Energy Sources: Even during a power outage, lines can undergo unpredictable re-energizing from several sources.

Common Electrical Hazards During Power Outages

During a power outage, many everyday electrical hazards still apply, but line workers also have to contend with outage-specific hazardous energy sources.

On top of that, the power outage itself, along with the pressure to get the lights back on, can lead to mistakes. Let’s look at some key unique threats to electrical line safety during outages.

Generator Backfeed

While generators are a common solution during a power outage, many people don’t realize that improperly installing a generator can result in a serious safety issue – not just for their own home, but for the surrounding area and any electrical workers performing power restoration.

During normal conditions, electricity entering a home is isolated and filtered for safety. When a portable generator is plugged into an appliance socket, these safety precautions are circumvented, and the energy from the generator goes straight into the home’s wiring. This puts the home at risk for short-circuiting and electrical fires, but it can also cause electricity to flow backward from the home into the surrounding area, energizing nearby power lines.

This is called a generator backfeed electrical hazard.

The use of a manual or automatic transfer switch can prevent backfeeding, but this isn’t understood by the general public. As a result, emergency electrical workers can’t assume that power lines are de-energized during a blackout because people inside the home or business may have generators back-feeding electricity to the main line.

Islanding From Distributed Energy Resources

Another special hazard that line workers might face in a power outage is an islanding electrical safety risk. Islanding is when a distributed energy resource (DER) continues to supply power to the local electrical grid even when the main grid is down. DERs are small-scale technologies that can generate, store, and feed electricity back to the power grid from the consumer’s side. Popular examples include home solar- and wind-powered generators.

As with backfeeding, islanding may result in energized electrical lines even during a power outage, therefore presenting an electrical shock hazard during power restoration work.

Automatic Reclosers

Automatic reclosers are typically programmed to attempt two to four reclosing attempts in case of a temporary electrical fault. Each attempt can deliver a high-energy current to the line if the recloser is not restrained.

Downed and Crossed Lines

If wires from different circuits or communication lines come into contact, unexpected voltage can be introduced to a seemingly de-energized line.

Stored Energy

Another unexpected energy source during an outage can be stored energy. Equipment can store energy even when disconnected from a main power source.

Stored electrical energy can come from capacitors, batteries, or lingering charge in the equipment. Other forms of stored energy include mechanical, hydraulic, pneumatic, chemical, and thermal.

Safety Principles Electrical Workers Should Follow During Outages

How do workers protect electrical line safety during outages, given these potential hazards?

Mindset and baseline safety assumptions can make a big difference. Below, we’ll review a few of the safety principles electrical workers should follow during outages.

Always Assume Lines Are Energized

The most important precaution for preventing electrical shock during power restoration is that all power lines may still be “hot” or energized. Workers who approach their job with that idea in mind greatly reduce the chance of a fatal error.

Since any of the lines could have current, it’s worth acting as if they all do until proven otherwise. Before contact with a seemingly downed line, workers must verify that the line is de-energized with rigorous testing.

Assume That De-Energized Lines Can Become Re-Energized

A line doesn’t become “safe” just because it’s been tested and found to be re-energized. Through the mechanisms we discussed above, any de-energized line can become re-energized at any time.

This is why temporary grounding at both sides of the work zone is non-negotiable.

Assume That Grounding Isn’t Foolproof

Line workers are trained in temporary grounding techniques under ideal, controlled conditions, but grounding in the field, under time constraints and, often, poor weather, is anything but.

Line workers should be aware that installation and removal of temporary grounding is, itself, a dangerous process. They should exercise special care during these transitions and take the time to question assumptions and assess the effectiveness of the grounding.

Finally, line workers should keep in mind that grounding may not fully mitigate exposure. They should assume that the protection offered by grounding is partial instead of complete.

Wear Properly Rated Personal Protective Equipment

Since complete protection from a re-energized line can never be guaranteed, line workers must always wear properly rated personal protective equipment (PPE) during outage response.

Necessary PPE during an outage includes properly-rated gloves and sleeves that undergo regular testing and inspection.

All work should stop if adequate PPE is unavailable or compromised. Without sufficient gear in place, repairs should not be attempted because of the risk of electrocution.

Lockout Tagout Procedures During Power Outages

Not all power outages are accidental. During a planned power plant outage for maintenance, lockout/tagout procedures are a critical precaution for electrical worker safety.

Lockout/Tagout, or LOTO, is a safety program that prevents “hazardous energy release” during maintenance or repair. The procedure includes:

1. Communicating the expected power shut-off to all relevant employees.
2. Identifying all hazardous energy sources.
3. Isolating identified sources, releasing any stored energy, and removing potential sources of kinetic energy.
4. Locking and tagging the hazardous energy sources so they can’t be unexpectedly re-energized.
5. Verifying equipment has been effectively isolated.
6. Coordinating re-energization with care, removing locks, notifying affected personnel, and ensuring everyone is clear.

Why Lockout Tagout Matters in Outage Conditions

LOTO procedures ensure that all equipment is shut down and de-energized before work begins. It protects workers from injury by the unexpected energization or the release of stored energy.

During a planned power outage, work crews have the time and control to follow a formalized and thorough LOTO process, and removing the risk of fatal errors makes the effort worthwhile.

During emergency restoration, work crews may be tempted to rush. While they aren’t expected to complete as extensive a LOTO process as they would during a planned shutdown, it’s still critical to perform the basics: rapid de-energization by switching, disabling reclosers, field verification, temporary grounding, and methodical re-energization.

Testing and Verification Before Power Restoration

Before power restoration, testing and verification of power lines are essential.

The steps for testing and verification before power restoration are as follows:

1. Confirm Isolation: Verify that all switches, breakers, jumpers, taps, and other sources are in the correct position.
2. Verify Clearance: The supervisor should confirm that all work is complete, all crew members are accounted for, and all tools, cover-up, and other equipment are removed from the line about to be energized.
3. Test For Absence: Test conductors for the absence of voltage to confirm that no unintended energy sources are present, including phase-to-phase and phase-to-ground. Always use the “test the tester, test the circuit, test the tester again” method to ensure that the detector did not fail during the test.
4. Visual Inspection: Look for damage, loose hardware, foreign objects, and signs of tracking or flashover. Confirm that protection and controls are set to the intended mode.
5. Re-Energize and Monitor: Re-energize the line in the approved switching order, verbally confirming each step to be logged by the control center. Then monitor load, voltage, and protective devices for abnormal indications. Be prepared to open the circuit again if an anomaly appears.

Test for High and Low Voltage

Standard testing must be performed for both high and low voltages.

Voltages between 601 and 230,000 volts are known as “high voltage,” and any number higher than 230,000 is called “extra high voltage.” These voltages present a serious risk of electrocution.

However, low voltages can also be deadly, which is why testing for high voltage alone is not sufficient. Workers must check lines for low voltage before work begins.

Line workers should always use testing equipment with high-intensity LED displays and audible alarms. This guarantees that readings won’t be missed even in less-than-ideal lighting or weather conditions.

How the Public Can Help Protect Electrical Workers

The public can help keep emergency electrical workers safe with a few important precautions, including:

• Getting your generator installed by professionals.
• Turning off the main breakers before using your generator.
• Avoiding unsafe electrical modifications during outages.

The Role of Training in Power Outage Safety

Training is often viewed as a compliance checkbox, but it’s also a legitimate way to prevent safety incidents. When workers understand the hazards they face and the role that safety procedures play, they’re more likely to remember and use proper precautions.

Electrical workers should undergo annual formal safety training, but they should also attend a pre-outage briefing where key aspects of power restoration safety training are reviewed and emphasized.

For effective safety training, consistency and repetition are crucial.

Lockout Tagout Training for Electrical Workers

As an OSHA-authorized training provider for over 20 years, our worker safety courses are up-to-date, effective, and convenient. Learners are able to study at their own pace, anywhere and anytime that works best for them. This allows for greater attention to and retention of the material.

We offer several Lockout/Tagout (LOTO) courses, including basic LOTO awareness, in-depth LOTO training, and a Spanish-language version.

Enroll today!