What Happens During a Power Outage in Access Control Systems?

Power outages are an unavoidable reality for commercial buildings. Whether caused by storms, electrical failures, or planned maintenance, a loss of power can impact security systems, electronic locks, and access control hardware. For facility managers, locksmiths, and installers, understanding how access control systems behave during a power outage is critical for maintaining both security and life safety compliance.

Different types of electronic locking hardware respond differently when power is lost. Some locks will automatically unlock to allow free egress, while others remain secure to prevent unauthorized access. This behavior is determined by the hardware design, system configuration, and the presence of backup power sources such as batteries.

In most commercial environments, access control systems are designed with fail safe and fail secure principles to ensure that doors behave appropriately during emergencies. These design choices help buildings remain compliant with fire safety codes while still protecting restricted areas.

Power supplies with battery backup also play a major role in maintaining access control functionality during outages. Many systems are designed to keep locks operational long enough for the building to safely transition during an emergency.

In this guide, we'll explain what happens to different types of access control hardware during a power outage and how proper system design ensures both security and safety.

Fail Safe vs Fail Secure Locks

The behavior of a door during a power outage largely depends on whether the locking hardware is fail safe or fail secure.

Fail safe locks unlock when power is lost, allowing free entry. These are commonly used on doors where safety and emergency egress are the top priority.

Fail secure locks remain locked when power is removed. This design prevents unauthorized access during a power outage and is commonly used for secure areas like server rooms, storage rooms, and restricted offices.

Choosing between these two options depends on building codes, fire safety requirements, and the level of security needed.

What Happens to Different Types of Electronic Locks?

Not all electronic locks behave the same way during a power outage. The way a lock responds depends on the type of hardware being used and how it has been configured within the access control system.

Electrified Mortise Locks

Electrified mortise locks can be configured as either fail safe or fail secure, depending on the specific model and electrical function.

In a fail secure configuration, the outside lever remains locked when power is removed, while the inside lever still allows free egress. This setup is commonly used for offices, storerooms, and other secure areas where maintaining security during a power outage is important.

In a fail safe configuration, the outside lever unlocks when power is lost, allowing entry during an outage. This configuration is typically used in applications where life safety codes require doors to unlock automatically during emergencies.

Many modern electrified mortise locks are designed with field-configurable electrical functions, allowing installers to choose the appropriate behavior for the application without replacing the lock.

Electric Strikes

Electric strikes can be configured as either fail safe or fail secure, depending on the type of strike installed.

Fail-secure strikes remain locked when power is lost, which helps maintain security during an outage. Fail-safe strikes unlock automatically when power is removed, allowing the door to open.

Because electric strikes work with the existing mechanical lock, their behavior during a power outage also depends on the function of the lock installed in the door.

Magnetic Locks

Maglocks are always fail safe by design. When power is removed, the magnetic bond releases and the door unlocks.

Because of this, maglocks are commonly paired with backup power supplies and safety devices such as request-to-exit sensors and fire alarm integrations to ensure proper operation during emergencies.

The Role of Backup Power Supplies

Many commercial access control systems are designed to continue operating during power outages through battery backup power supplies.

These power supplies keep electronic locks, keypads, and access control panels running long enough for building occupants to safely exit or for emergency systems to take over.

Typical access control power supplies support battery backups that can maintain system operation for several hours depending on the load and battery capacity.

Properly sized power supplies are essential for ensuring that electrified hardware continues to function during unexpected outages.

Fire Alarm Integration and Emergency Unlocking

Many access control systems integrate with a building's fire alarm system. When a fire alarm is triggered, the system can automatically release certain locks to ensure safe evacuation.

For example:

• Maglocks are often released through fire alarm relays
• Electrified locks may change state depending on configuration
• Access control panels may unlock designated emergency exits

These integrations help ensure compliance with life safety codes while maintaining normal security during everyday operation.

Conclusion

Power outages don't have to compromise building security or safety when access control systems are designed properly. Understanding how different types of electronic locks behave during a loss of power is essential for choosing the right hardware and ensuring compliance with safety regulations.

By combining the right locking hardware with properly configured power supplies and emergency integrations, commercial buildings can remain secure while still protecting occupants during emergencies.

For installers and facility managers, planning for power outages is simply part of designing a reliable access control system.