Electrified door hardware has achieved new levels of acceptance as our society attains a more mature attitude with respect to the importance of safety and security. What might have been judged paranoia a few years ago may now be regarded as just common sense today. The two most important...
To access the remainder of this piece of premium content, you must be registered with Locksmith Ledger. Already have an account? Login
Register in seconds by connecting with your preferred Social Network.
Complete the registration form.
Used with access control systems, installers may find The Latch Monitor/Keeper Monitor a great benefit. The latch monitor provides a signal to the access control panel that indicates that the latch is in the locked position, and therefore that the door is also closed. Perhaps an even better use for the latch monitor is to trigger the REX (Request to Exit). Here's an explanation of how and why you would want to do this:
The typical access control system unlocks the door when a valid credential is presented to the reader associated with the door. The system monitors the door's position so that when the access is granted, the system will generate an alarm if the door is held open too long after a valid access, or if the door is opened without a valid credential being presented first. However, in most systems, there must always be free egress through the door, that is people are usually allowed to pass through the door from the protected side to the unprotected side, and usually it is desirable to 'suppress' forced door alarm messages to the control panel for these types of allowable door usage.
In order for the system to be able to know when the door being opened is for the purpose of egress, (as opposed to the door being forced open), system designers provide a REX (Request TO Exit) device on the interior side of the door. This can be a motion sensor, or a button, or a switch built into a touch bar (exit device).
An alternative is connecting the latch monitor to the REX terminals of the access controller. When an individual leaving the protected area turns the knob or lever to leave, the latch retracts; the latch monitor sends a signal to the access controller, and a forced door message is suppressed. When the latch monitor is used in this way, it will probably be advisable to install some other type of door position sensor, because the keeper monitor may not provide enough protection for the door. One drawback of using the latch monitor for REX is that if a key is used to gain access to the protected area, the entrance will be annunciated as a REX. If this is objectionable, the deactivate the cylinder, combinate it so that it is impossible to pick, and simply don't distribute any keys which will operate the lock.
Overall we were pleased with the flexibility of this strike with respect to being able to use it for both metal and wood, and field select the voltage. We also took full advantage of the ability to field set for Fail-safe or Fail-secure. On one group of doors we were doing, the access control system was not ready to be commissioned, and we did not want to inhibit use of the doors even though the strike was installed. So we set the strikes for fail-safe.
These doors could be used normally without restriction. However, another door in the facility was currently being controlled by a mechanical pushbutton lock, and even though were not ready to commission the access control system, at the time we installed the electric strike, we set the strike to Fail-Secure and the employees continued to use the mechanical pushbutton lock as usual, until the access control system was ready to go on line.
For information, contact your local locksmith distributor or RCI, phone 800-265-6630 / 800-899-5625, web site www.rutherfordcontrols.com.
An electric strike is a latching mechanism that operates electrically to secure or release the extended latch or bolt of a mechanical lock or exit device. When an electric strike releases the latching...
Electric strikes were invented approximately a century ago to meet the basic need of remotely unlocking a door. For most of those years, the lowly electric strike changed very little and just a...