How to Survey a Job Site for Electric Locking

An access control system that is hard wired and/or centrally controlled is nothing more than a fancy electrical switch that is used to turn some kind of electric locking device on and off. When you present your credential (prox card or fob, mag stripe card, pin code on a digital keypad, etc.), the access control system changes the state of an electrical relay that then supplies or discontinues power to the locking device. This article talks about how to choose electric locking devices for different situations.

Note: To use an electric strike with a cylindrical lock, the cylindrical lock must either have a blank handle always locked from the access side or be a keyed function, preferably storeroom function.

Cylindrical Lock on a Hollow Metal Door or Wood Door with Metal Door Frame

1. Non-fire rated door. Choose an electric strike designed for a cylindrical lock, such as: >Adams Rite 7440 >HES 5000 with 501 option faceplate >HES 5900 with 591 option faceplate >Von Duprin 6211
2. Fire rated door that can be left locked during a fire (fail secure): >Adams Rite 7240 >HES 7501 >Von Duprin 6211 Any of these three listed above could also be used on a non-fire rated opening.
3. Fire rated door that must be unlocked in the event of a fire (fails safe): An electric strike cannot be used on this door. Use an electrified cylindrical lock instead, such as: >Corbin CL33903 >Schlage ND80PDEL Your electrified cylindrical lock will need a means of transferring power from the door frame into the door. I suggest an electric hinge, such as: >Stanley CEFBB179-54 4-1/2 X 4-1/2 US26D

An electrified cylindrical lock can also be a good choice when your door frame is filled with concrete. An electrified cylindrical lock can be used on any door that you can run a wire through to power it.

Security Door Controls and other manufacturers offer door coring tools to assist with drilling the hole through which to run the wire from the electric through-wire hinge to the electric lock.

You could also use an electromagnetic lock on a fail safe fire rated opening if your local Authority Having Jurisdiction (AHJ), that is, fire marshal or building inspector, approves.

Cylindrical Lock on a Wood Door with a Wood Door Frame

Blank (Slab) Door with No Glass

• If the wooden framing will support an electric strike, use: >HES 7505 >Von Duprin 6211WF >HES 5000 with 502 option faceplate
• If the frame will not support a strike, for example, if there is a side lite hard against the frame, use an electrified cylindrical lock and electrified hinge as described above.

Door with Large Glass Window

• This kind of door can be a challenge. If the frame will support an electric strike, use one such as those listed immediately above. If not, you can core the door for a wire from the top hinge across to the lock stile, and then down through the lock stile to the lock prep, and use an electrified cylindrical lock. The easy way out would be to use an electromagnetic lock, once again if your AHJ will approve.

In the case of a mortise lock, the hardware is different, but the principals are basically the same.

Like the cylindrical lock, the easiest electric strike install is with a storeroom function mortise lock. Unlike cylindrical locks, some mortise locks, such as those shown at right, have integral deadbolts. It is possible to release a mortise lock with a deadbolt using an electric strike, but it is more complicated. The simplest kind of mortise lock to use with an electric strike is one that is always locked on the outside, always unlocked on the inside, and has no deadbolt. Mortise lock functions can be easily changed by replacing the lock body with one of the correct function. The cylinder and levers can be re-used.

Mortise locks also differ from cylindrical locks in that the hole, or keeper, in their strike plate is offset toward the bottom. This means that the keeper of an electric strike that is compatible with mortise locks should also be offset toward the bottom, unless the doors and frames are being made new. In the case of brand new doors, simply give a mortise lock with the correct function and any electric strike with a 3/4 inch deep keeper to the door manufacturer. They will prep the frame so that the electric strike lines up with the mortise lock, whether the keeper is centered or offset.

In the situation below, we assume that these are existing doors to which we want to retrofit an electric strike.

Mortise Lock on a Hollow Metal or Wood Door with a Hollow Metal Frame

• Non-fire rated applications, or fire rated applications that can remain locked in the event of a fire, use one of the following strikes:

  >Von Duprin 6210

  >HES 4500 (not compatible with all brands)

  >HES 1006 (select the faceplate option that works with your brand of lock.

• Fire rated applications that must remain unlocked in the event of a fire (fail safe):

  An electric strike cannot be used for this application. Instead, use an electrified mortise lock and an electric hinge. An electrified mortise lock can also be a good choice for opening swith grouted door frames (door frames filled with concrete).

With AHJ approval, an electromagnetic lock could also be used.

Mortise Lock on a Wood Door with a Wood Frame:

• If non fire rated or fire rated that can remain locked in the event of a fire, use one of the following electric strikes:

  >Folger Adam 310-2-3/4

  >Von Duprin 6211WF

  >Folger Adam 732-75

• If fire rated that must be fail safe, use an electrified mortise lock and electric through-wire hinge or an electromagnetic lock.

Your electric locking options change depending on the kind of exit device you have, whether or not your opening is fire rated, and whether or not your application is Fail Safe or Fail Secure.

Rim Exit Device

• Non-fire rated: Use one of the following: >HES 9600 electric strike >Trine 4800 electric strike >Von Duprin 6111 or 6112 electric strike >Electric Latch Retraction
• Fire rated, fail secure application: >HES 9500 electric strike >Electric Latch Retraction >Electrified Outside Trim
• Fire rated, fail safe application >Electrified Outside Trim

Mortise Exit Device

• Fire Rated Fail Secure, Non-Fire Rated Fail Secure or Fail Safe applications: >See Mortise Lock section above for electric strike choices. Electric strike selection will depend upon strike offset. >Electrified mortise lock is also an option. >Electrified outside trim
• Fire Rated or Non-Fire Rated Fail Secure applications: >Electric Latch Retraction>Electric Strike>Electrified Mortise Lock>Electrified Outside Trim
• Fire Rated, Fail Safe applications: >Electrified mortise lock>Electrified outside trim

Vertical Rod Exit Device, Surface or Concealed:

• Fire Rated, Non-Fire Rated Fail Secure Appications>Electric Latch Retraction >Electrified Outside Trim
• Fire Rated, Non-Fire Rated Fail Safe Applications>Electrified Outside Trim

It is possible to use electric strikes on vertical rod exit devices, but it is not something I recommend if there is any way to avoid it. Since, to use an electric strike you must lose the bottom rod, the bottom of the door is not secured. Depending on how flexible the door is, you might be able to pull the bottom open six or eight inches. Add to that the play in the electric strike and you have one very sloppy door.