Electric Hardware: Fail Safe VS Fail Secure

Electric locks and electric strikes commonly require you to indicate if you want them to be Fail Safe (FSA) or Fail Secure (FSE). But what do these terms mean? We’ll answer that question today and help you understand some of the benefits and drawbacks to both.

Fail Safe VS Fail Secure

You’ll notice that both terms begin with the word “Fail“. This tells us that when the hardware fails (power is lost) then the hardware will be in either a “Safe” or a “Secure” state. Most hardware devices will allow free egress no matter what happens.

Fail Safe Electric Hardware

Electric hardware devices that are Fail Safe will remain unlocked if power is cut off or lost. The term Safe means that people can get in and out of that opening if the power is lost, such as in an emergency event like a fire. When the fire alarm goes off, a signal is sent to the hardware to remove power and the result is safe entrance or exit through the opening.

Additionally, hardware that is Fail Safe will require constant power to remain locked. When authorized personnel present the correct credential (i.e. the correct keypad code on the lock) then a signal is sent to cut the power which unlocks the hardware allowing entry. After a few moments power is restored to the hardware and it is locked.

Fail Safe is a common application for Hospitals or Stairwell doors because if an emergency event occurs, people can exit the building and get to safety quickly.

Fail Secure Electric Hardware

Electric hardware that is Fail Secure will remain locked if power is cut off or lost. The term Secure means that people cannot get into that opening if the power is lost, but people can still get out if needed. If the power is cut in an emergency or a failure in the system occurs, these locks will keep the room or area secure from unauthorized entry. A manual override (such as a key) would be required to gain access.

Hardware that is Fail Secure requires power to be unlocked. When the proper credential is presented (i.e. the correct key card) a signal is sent to supply power to the lock which then unlocks the hardware allowing entry. After a few moments the power is shut off and the hardware is locked.

Fail Secure is useful for areas that need to be restricted at all times, even in the event of an emergency. You’ll often see Fail Secure hardware in Pharmacies, Banks, and areas where sensitive information is kept such as data rooms or file rooms.

Electric Strikes

Electric strikes are going to be Fail Secure 99 times out of 100. There are a few reasons for this.

If an electric strike were to be Fail Safe then constant power is supplied to keep it locked and latched. The constant power required for a Fail Safe application causes the electric strike body to heat up. If someone touches it by accident it could hurt them. Additionally, if power is lost in an emergency, there is a possibility that the door could be left unlatched even after the power is restored.

Electric strikes are therefore more efficient when they are Fail Secure and they remain secure in an emergency. If the opening is to be fire rated then the locking hardware is required to remain latched. Fail Secure electric strikes will keep the door latched even when the power is cut in a fire emergency.

Electromagnetic Locks

Electromagnetic locks will be Fail Safe 100 times out of 100. There is one major reason for this.

Electromagnetic locks (or Mag locks) require constant power to remain locked. Once power is dropped, there is no holding force to keep the door locked. Some times Mag locks are specified at an opening with no latching hardware which means the mag locks are going to be the only hardware that secures the opening. The Fail Safe setting will keep that door locked and then allow free entry and egress if power is cut off or lost. Generally, it is best to have other latching hardware on the door with Mag locks.