What Is an EPO in Construction? Essential Safety Insights

June 12, 2024

An Emergency Power Off (EPO) button, also known as an EPO switch or EPO panel, is a critical safety device designed to quickly disconnect electrical power to equipment or even entire facilities during emergencies. This ensures a swift and safe shutdown of all power sources, which include uninterruptible power supplies, batteries, and generators from a central location.

Situations Requiring an EPO Button

Emergency Scenarios

EPO buttons are designed for use in situations where there is a potential for loss of life or substantial property damage. These scenarios include:

  • Fires
  • Evacuations
  • Floods
  • Risks of electrocution

Locations to Find EPO Buttons

Common Installations

EPO buttons are typically installed in various high-risk environments such as:

  • Manufacturing plants
  • Telecommunications facilities
  • IT data centers

Importance of Centralized Power Shutdown

Preventing Damage

A centralized power shutdown via an EPO button significantly reduces the potential damage during disasters. It stops electrical fires from spreading and minimizes the risk to equipment and infrastructure.

Safety for Rescue Operations

Activating an EPO button allows safer conditions for emergency personnel who need to handle the situation, whether they are dealing with fire, water, or electrical hazards.

Considerations for Installation

Clear Marking and Protection

To ensure the efficacy and prevent accidental activation, EPO buttons should be:

  • Clearly marked
  • Installed under a clear, lift-cover box
  • Preferably equipped with an integrated alarm

Avoiding Unintentional Downtime

Accidentally pressing the EPO button can have significant negative implications, such as:

  • Significant revenue loss
  • Extended downtime due to improper shutdown of systems

Regulatory Requirements

Standards and Codes

The specific requirements for the size, placement, and accessibility of EPO buttons vary by jurisdiction. Historically, codes required EPO buttons at every exit door. However, the 2011 National Electrical Code (NEC) allows a single EPO switch placement in a nearby room, given approval from a code inspector and fire marshal.

Integration with Other Systems

Linked Controls

EPO buttons may be interconnected and managed from a central point. They often tie into fire panels or building control systems to automatically activate an EPO before activating fire sprinklers, minimizing the risk of electric shock.


Supplier Examples

There are several suppliers for EPO buttons, including well-known companies like:

  • APC by Schneider Electric
  • Safety Technical International

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