Electronic Cabinet Locks

May 3, 2010
Security for inside and outside of the cabinet

Most office furniture lock mechanisms are wafer tumbler. In most instances, the file cabinets and desks themselves do not offer much protection against unauthorized access. Some employees are more than willing to unlock the lock, remove the key and leave the cabinet door unlocked. This results in almost no security except that people may think the cabinet is locked if the door is shut.

One alternative has been to install a key-retaining mechanical lock. The key can only be removed in the locked position. It seems that some offices have found the way around this alternative solution. An employee can unlock the lock, open the cabinet door, lock the lock and remove his or her key. Problem solved. This is even worse as the lock is locked and the cabinet door cannot be closed to give the appearance of security.

Enter the electronic cabinet locks no key required. Electronic cabinet locks are magnetic, motor or solenoid operated and designed for interior, non-entry door applications. A commercial solenoid uses electricity to create a magnetic field to move the steel armature (plunger) in order to unlock the locking mechanism. Solenoids require a significant amount of current (inrush) in order to move the armature. For Fail Secure solenoids once unlocked, power is removed and the locking mechanism relocks.

An electric motor also incorporates a mechanism similar to the loop of wire used by a solenoid. However, the magnetic field in an electric motor causes the armature to rotate, removing the obstacle from the locking mechanism or retracting the latch or bolt mechanism. Once the locking mechanism is no longer locked, the cabinet can be opened. Unlike a solenoid, the motor must reengage and operate to relock the locking mechanism.

Both the solenoid and the electric motor perform similar functions to create the same results of providing access to the content of the cabinet. However, the current draw of a solenoid is usually significantly greater when compared to an electric motor. Some of the electric motor-driven electronic cabinet locks are sold as battery operated.

An electromagnet is a magnet whose magnetic field (holding power) is produced by the flow of electric current. To strengthen the magnetic field, wire is wound into a coil with a metal core. When an electromagnet is powered, and is in close proximity, the strike becomes magnetically attached to the lock. The magnetic field disappears when the electrical current terminates, releasing the strike.

Cabinets, lockers, supply doors and other fixed storage equipment can be equipped with electronic locks. Some standalone, battery powered cabinet locks are designed to retrofit cam locks. Each unit can be used to secure one cabinet door.

Standalone locks provide the locking mechanism and the access control mechanism in one. Four models will be discussed: the Rutherford Controls Inc. (RCI) 3511, DIGITLOCKS DL1230-K and the CodeLocks CL1000 and CL1200 Series.

The RCI 3511 battery operated “Lock-in-a-Box” is a complete system designed to have the lock installed within the cabinet. It uses iButton® keys and includes key management software designed for up to 160 users. Programming is simplified by using Add, Delete, User and Shadow keys. The locking mechanism is an eyehook armature installed onto the interior of the swing side of the door. The eyehook is secured with the electronic bolt lock that provides 180 pounds holding force.

The RCI 3511 lock body is surface mounted adjacent to the swing side of the cabinet door with the eyehook mounted onto the door. When the door is closed, the eyehook enters the slot in the lock body and the locking bolt slides into the eyehook locking the cabinet.

The iButton reader is surface mounted in proximity of the cabinet door. To operate the lock, place a programmed iButton against the reader, and the lock unlocks so the door can be opened.

The RCI 3511 can be installed onto wood and metal cabinets. The battery is designed for three years or 350,000 operations. An emergency mechanical override option is available.

The DIGITLOCKS Inc. DL1200 Series of battery operated, electronic cam locks are equipped with a 12-button (2x6) keypad. The buttons are 1-10, C and #. Between the two columns of buttons, DL1200 Series locks have a printed sleeve that provides the option of letters arranged according to the alphabet, separated in common with a telephone. For example, the “2” button has the sleeve letters ABC. Like an all-letter telephone number, the DIGITLOCK DL1200 Series can be coded in the same way.

Model DL1201-K is a one user code lock. Model DL-1230-K is a 30-user code lock with key bypass. The users can be programmed as one-time users or standard user codes. Once a single-use code has been entered, the code is no longer valid when the lock has been relocked.

The code hierarchy is a Master, optional sub-master, up to 30 user codes or single use codes. The Master Code is programmed first and can be four to six digits in length. The length of the Master code sets the length of the Sub-Master, User and Single Use Codes. The Master Code can enter passage mode, suspend any or all codes and restore default codes and modes.

Two AAA batteries providing 15,000+ cycles power the DL-1230-K. A low battery warning signals (no audio) on the LEDs signals when they need to be replaced. In the case of dead batteries, the electronic cam lock has terminal on the bottom for unlocking with a 9volt battery.

The DIGITLOCKS DL-1230-K is 5-1/2” long by 1-3/8” wide by 1-3/8” deep. These electromechanical cam style locks are designed for new installation or can be retrofit to replace an existing cam lock. To simplify installation, the DL-1230 is equipped with field changeable spindle lengths to accommodate various door thicknesses. The door thickness range is from 1/4” (sheet metal) up to 1” thick. A straight cam and an offset cam are included. The hook cam is available as an option. These cabinet locks can be installed vertically or horizontally. For ADA locker compliance, DIGITLOCKS offers a small lever handle option for the DL-1230-K.

The standalone, door-mounted CodeLocks CL1000 and CL1200 Series electronic cabinet locks are one-piece battery powered units that operate a cam to lock and unlock the cabinet. “CL” locks are designed to retrofit cam lock applications that are large enough to accommodate the approximately 5-1/2” long lock bodies. CL1000 Series Cabinet Locks are available in 3/8”, 5/8”, 7/8” and 1-1/8” door thickness. Ten individual buttons operate the CL1200 Series locks. Five rocker switches operate the 10 digit choices for the CL1000 Series locks.

CodeLocks CL1000/CL1200 Series cabinet locks have four user levels: master code, sub-master code, user code and a single use locker mode code. The master and sub-master codes are eight digits in length. The User code is four digits. The Master Code programs the Sub-Master and the User Code. The Sub-Master Code can also program the User Code. The use programs the single-use locker mode code.

For example, at a gym, the lock is unlocked until a person places his belongings in the locker and programs a four-digit code. Once the code has been programmed, the lock becomes locked. When this code is again entered, the lock unlocks and remains unlocked until another four-digit code is programmed. If this code is forgotten, the Master or the Sub-Master Codes can open the lock, erasing the single-use locker mode code.

The CL1200 Series is supplied with four lengths of spindle adaptor that can accommodate most door thicknesses. Two AAA batteries provide up to 12,000 operations for CL1000 locks and up to 50,000 operations for the CL1200.

In case of battery failure, a 9 Volt battery is placed over the CL1000 LED’s (red +/blue -) providing power and the lock can be unlocked by entering the Master Code. The CL1200 has 9 Volt battery contacts along the bottom.

Component electric solenoid and/or battery powered cabinet locks are available from manufacturers including CompX, HES, RCI, Schlage (Locknetics), Securitron and Security Door Controls. This sampling of component-based electronic cabinet lock mechanisms includes spring latch, bolt, catch and receiver, electric strike or magnet.

Before installation, check with the manufacturer to determine the operating requirements of the device (lock, controller, reader, etc.). Make sure the output voltage of the power supply or plug-in transformer is within range prior to powering the system. Excess voltage can cause severe damage to the lock hardware.

CompX Security Products eLocks are complete, standalone electronic locking systems available in a number of configurations including keypad, magstripe, proximity, AND combination readers with proximity and keypad, and proximity and magstripe. The eLock connects to a motor driven spring latch mechanism using a 24” latch cable. The eLock has a built in tamper alarm.

The patented HES 660 is a surface mount electro-mechanical 12 or 24VDC lock providing 1,000 pounds of holding force. Two options are available: Lock Bolt State Monitoring (LBSM) and pre-load. The LBSM is used if the lock bolt is in the locked condition. Pre-load provided the ability of the lock to unlock when the hook bracket presses against the bolt in the locked condition.

The HES 660 lock is mounted onto the interior of the cabinet or drawer using adjustable lock mounting brackets. The latching assembly is a hook bracket assembly mounted onto the interior of the swing side of the door.

Schlage (Locknetics) manufactures the 400 Series Electromechanical Cabinet Locks for non-entry doors and drawers. The 442S (Solenoid) Cabinet Lock is a Fail Secure solenoid operated locking mechanism. The Schlage 443BP (Battery-Powered) cabinet lock is powered by four AA batteries. Both locks can be mounted horizontally or vertically and the locking bolt can be accessed from the front or sides to accommodate swing and sliding doors and drawers.

The Security Door Controls 290 surface mounted electro-mechanical lock is designed to accommodate front and side entry of the strike for securing swinging and sliding non-entry doors. The field reversible 12/24VDC solenoid can accommodate Fail Safe and Fail Secure operation. To change the lock mode operation, the solenoid position is reversed.

The SDC 290 Micro Cabinet Lock is available with an optional lock status switch. The voltage draw is approximately 250mA @12VDC and 130 mA@24VDC. The overall size of the lock body is 3.25” L by 1.125” W by 1.125” D.

Securitron Magnalock Corporation offers two types of cabinet locks electromagnetic locks and a solenoid lock. The M32-SS, split strike, 300-pound holding force Magnalock and the MCL-24, a 200-pound holding force Magnalock, are designed for non-entry door applications. Both magnetic locks are designed for swinging and sliding cabinet doors. The split strike M32-SS can be installed to secure both doors of a double door cabinet. The shipping weight of the MCL-24 is 1.5 pounds. Dimensions of the MCL-24 are 4.625” L by 1.14” T by .75” D. The dimensions of the M32-SS are 8” L by 1.88” T by 1.6” D.

The SCL is a 600-pound 12 or 24VDC Fail Secure solenoid-operated cabinet lock, with a shipping weight of 0.4 pounds. The lock body mounts onto the frame of the cabinet and the keeper mounts onto the moving door or drawer. The SCL is surface mounted and will accommodate front and side entry of the keeper for securing swing and sliding non-entry door applications. Securitron’s Solenoid Cabinet Lock Tool (SCLT) is an aluminum alignment template for positioning the keeper when mounting SCL Cabinet Locks.

The MCL-24, M322-SS and the SCL cabinet locks are covered by the MagnaCare Lifetime Replacement Warranty.

HOSPITAL APPLICATION

Thinking beyond the “fixed-in-position” cabinet for which these locks were designed, electronic cabinet locks are being used to secure a variety of internal and external items.

At a large facility, a locksmith created and installed a lock for a rolling ladder that is kept in a storage room. He used a CompX eLock with motorized latch, heavy gauge custom made metal cabinet and Pullman latch mechanism from a rim exit device. The metal cabinet was secured to a steel support beam within the wall.

The locking concept behind this rolling ladder lock is a “C” shaped bar welded to the ladder in order to get it close enough to the wall. The wall -mounted metal cabinet has a “U” shaped receiver into which the modified “C” shaped bar can slide. The “C” shaped bar has a closed end and bracketing that obstructs tampering to the Pullman bolt.

As the rolling ladder is moved into position, the bar passes the cabinet mounted Pullman latch, causing it to retract on entry into the receiver. Once seated, the Pullman latch extends, preventing the rolling ladder’s release. Many different job classifications have access to this storage room; only the maintenance personnel have access to the rolling ladder.

To control access, a battery powered CompX Prox /Keypad Combo eLock is mounted onto the front of the metal box. The eLock’s motorized latch (a hole drilled through the tip of the latch itself) and the Pullman Latch are mounted inside of the box. A metal rod connects them.

Employees of this facility have Prox-equipped identification badges. The maintenance personnel who have access to this storage closet use their badges to gain access into the room and to release the rolling ladder.

SECURING A ROLLING CART

In hospitals, rolling carts hold patient records, drugs, emergency supplies, etc. In the early days, “crash” carts were Craftsman rolling toolboxes. Today, specialty carts equipped with electronic locks are in the price range of $5,000. Some hospitals already have carts; retrofitting electronic cabinet locks is not that difficult.

Securing a rolling cart does not provide burglary protection. The cart is on wheels and could be rolled out of a building. If there is a reason for higher levels of security, specifically designed drug rolling carts are manufactured of metal or similar components. Controlling access to the contents of rolling carts can be accomplished using battery-operated cabinet locks and readers.

For this five-drawer rolling medical supply cabinet, the Schlage 443BP Cabinet Lock and the PRO 78 keypad controls access by limiting rotation of the drawer release, gravity drop mechanism on this mainly plastic cart. The knob is rotated, retracting the top and bottom pins.

Behind the exterior rotating knob on the swing out door, the top and bottom rods are connected to a metal wheel. When the knob is rotated, the top and bottom rods either extend or retract, locking or unlocking the drawers.

To secure the drawers on this rolling cart, the Schlage 443BP lock was installed adjacent to the metal wheel. An armature was attached to the wheel and the strike mounted onto the armature. When the knob is rotated to the locked position (rods extended) the strike opening is aligned with the path of lock bolt.

Another hospital rolling cart had just been modified and was being tested. The cart originally came with individual keyed drawer locks. For this application, the CompX eLock with “prox” and keypad was installed as there would not have to be additional programming as the hospital personnel have “prox” equipped name badges. The finished units would be equipped with a cover protecting the locking mechanism.

This cart required not only an electronic cabinet lock, but also the locking mechanism. The locking mechanism developed is a gravity drop style similar to a multiple drawer file cabinet. The locking mechanism is a vertical moving plate that has rods attached for each drawer. In the locked (down) position, into each of the two upper drawer tracks would have a rod extending into the drawer path. Along the edge of the drawer, a triangle shaped piece of metal is mounted be mounted. The right triangle of metal performs two functions: stopping the drawer from opening when the lock is in the locked condition and raises the metal locking plate as the drawers are slid in to permit the drawers to lock at anytime.

An “L” bracket was mounted vertically onto the left side of the cart in order to mount the CompX eLock. Behind the eLock, the spring latch components were installed along with the gravity drop locking mechanism. The spring latch in the vertical down position is attached to the locking mechanism. When the proper code is entered, the motorized spring latch retracts, lifting the locking mechanism, raising the two rods out of the way of the metal triangles. In the unlocked position, the two drawers can be opened.

Once the spring latch lock has timed out, the locking mechanism slide down into the locked condition. The drawers can be slid shut and locked without having to unlock the eLock.

In addition to securing non-moving cabinets, electronic cabinet locks can be used to secure a number of different products from rolling ladders to paperwork and hospital supplies.

For more information on the manufacturers mentioned in this article, contact your local locksmith distributor or: CodeLocks, 2930-B College Avenue, Costa Mesa, CA 92626. Telephone: 714.979.2900. Web Site: www.codelocks.us

CompX, P.O. Box 200, Mauldin, SC 29662. Telephone: 864-297-6655. Web Site: www.compx.com DIGITLOCKS Inc., 2973 Harbor Blvd., Suite 631, Costa Mesa, CA 92626. Telephone: 714-465-4580 Web Site: www.digitlocks.com HES, 22630 N. 17th Ave., Phoenix, AZ 85027. Telephone: 623-582-4626. Web Site: www.hesinnovations.com Rutherford Controls Inc., 2697 International Parkway, Pkwy 5, Virginia Beach, VA 23452. Phone: 800-265-6630 Web Site: www.rutherfordcontrols.com Schlage (Locknetics), 11819 North Pennsylvania St., Carmel, IN 46032. Phone: 800-847-1864. Web Site: www.schlage.com Security Door Controls, 3580 Willow Lane, Westlake Village, CA 91361-4921. Phone: 805-494-0622 Web Site: www.sdcsecurity.com Securitron Magnalock Corp., 550 Vista Blvd, Sparks, NV 89434. Phone: 775-355-5625. Web Site: www.securitron.com