Converting Mechanical to Electronic Access Control

Dec. 1, 2014
Cylindrical Locks, Exit Devices, Exterior Trims and Mortise Locks can be converted to electrical operation. Command Access Technologies can do the conversion or can provide field install kits.

There are many reasons to upgrade a commercial doorway equipped with mechanical to electrified door lock hardware. Electronic access control provides credential choices, remote keyless access, higher levels of security, time scheduling, holidays and audit trail. In addition, incorporating electronic access control eliminates the possibility of lost or loaned keys. Additional advantages include easier access for physically challenged individuals, better control over high traffic doors, traffic flow and the option of hands-free access and egress where desired or required.

Electrifying door lock hardware does not necessarily change the operational or locking mechanism. It usually adds either a solenoid or a motor-driven mechanism to either retract the latching mechanism, or lock and unlock the lock mechanism, controlling the operation of the exterior and, where applicable, the interior lever.

Four types of mechanical door lock hardware can be converted to electrical operation:

  1. Cylindrical Locks
  2. Exit Devices
  3. Exterior Trims
  4. Mortise Locks

Of these four types, two can be configured to electrically retract the latch and three can be configured to lever control. Exit devices and mortise locks can be configured for latch pullback operation. Retracting the latch enables people to simply push or pull the door open to gain access with no need to rotate the knob or lever or press the pushpad.

The three lever-control electrified operations are the cylindrical lock, mortise lock and exterior trim. When any of these three are converted, the mechanism locks (Fail Safe) or unlocks (Fail Secure), releasing or securing the outside lever. When the outside lever is unlocked, to gain access, the latch must be retracted before the door can be swung open. This type of modification does not retract the latch.

The application and the end users' resources usually determine the type of electrification.

There are two basic ways to electrify mechanical door lock hardware to electronically lock, unlock or to retract the latch ‑ purchasing new electrified door lock hardware or modifying the existing door hardware. Purchasing new door hardware is more expensive than electrifying existing door lock hardware. Before making a decision, consider the age and condition of the lock hardware. If the lock hardware is not in good operating condition or appearance and the company is planning upon staying in the building for a number of years, purchasing new electrified door hardware may be the best option.

When purchasing new electrified lock hardware, options are purchasing the electrified model of the same manufacturer or purchasing a different electrified model or brand. Some lock modifiers offer their own product lines of cylindrical, mortise, trim and exit devices. If the job also entails purchasing modification kits, purchasing from the same company can be advantageous as technical support is one telephone call. However, alternative lock hardware may not look identical, which is also an important consideration.

The alternative to purchasing new is to modify existing lock hardware. Some companies sell field installable kits. Unfortunately, not every cylindrical lock, mortise lock, trim or exit device can be field-modified.

When there is no field installable kit available or the locksmith does not want to make the modification, some companies modify the lock hardware in-house. For this option, the door hardware must be removed from the door and shipped to the modifier. The company must have replacement hardware available until the modified lock hardware has been returned. Most companies do not maintain large numbers of backup product. As a result, the modification process would have to be piecemeal. For large jobs, this would require too much time, becoming financially impractical.

Field installable kits are available for some manufacturers' models of cylindrical locks, mortise locks and some exterior trim. Most pushpad-equipped surface vertical rod and rim exit devices have field installable kits.

Before meeting with the company, ask to be given the opportunity to walk the property with a list of doors that are being considered for electrification. Answer the following five questions to better understand opening condition and what is necessary for electrification.

  1. Is the door and hardware in operating condition?  If the door does not swing closed and latch, there is no security. Repairs to the opening, closer or hinges must be made before considering electrified door hardware. 
  2. Is the opening on the exterior or interior of the building?  It is never a good idea to install a solenoid equipped mechanism on the outside of an exterior door. Solenoids are especially sensitive to moisture. 
  3. Is the opening fire rated?  Knowing if the opening is fire rated determines the replacement door hardware or the kit that can be installed. It also determines the hardware functionality. Fire rated openings must securely latch when power has been removed .
  4. Is the door able to accommodate the electrified lock hardware?  This is determined by the hardware on the door, the codes and regulations, the desired operation of the door and the availability of bring power to the opening and to the hardware.
  5. Is there a noise issue if the electrified hardware is installed onto the secured side of the door?  Installing electrified exit device trim places the solenoid on the exterior side of an interior door. Limiting the noise from emanating through the door. A solenoid equipped lock or latch pullback exit device will produce more sound.

Then discuss with the end user the reasons they are considering adding electronic access control. It is a good idea to discuss what they hope to accomplish. Discussing each opening separately will help you understand their needs and wants. Offer suggestion of possible additions including power operator and accessories that notify if the door is not secure. The more you know about the job, the more likely your recommendations will be the best solution for each opening.

Consider the following factors when deciding which component to electrify: exit device trim or pushpad-equipped exit device.

Electrified trim is designed to lock and unlock the lever. The exit device uses a latch pullback mechanism that retracts the latch. The latch pullback mechanism retracts the pushpad when unlocked. The exit device is electrically dogged, creating a push-pull condition. The act of access or egress does not operate the exit device. Electrically unlocking the trim requires the lever to be rotated to retract the latch. Rotating the lever operates the exit device adding the operational wear.

Electrified exit trim is less expensive than electric pullback exit device for stairwell conditions where fire/life safety codes require a Fail Safe condition or applications where electric pullback exit devices are not required. The trim is mounted onto the unsecured outside of the door. The exit device is located on the secured inside of the door.

Electrified exit device trim draws approximately 250mA @ 12Volts or 150mA @ 24Volts. This is a smaller power requirement than an exit device equipped with motor driven latch pullback. The average solenoid latch retraction exit device requires a 12-16 Amp inrush and approximately 500mA @ 24 Volts to keep the latch retracted.

The electrified trim requires the wire run to the lock side of the door with approximately 18 gauge wires. The electrified exit device requires a short run into the door with a smaller (thicker) gauge wire. Wire gauge varies by length of wire run.

A door operator will operate with latch pullback equipped exit device. It will not work with an electrified exit device trim.

There are two types of electrified mortise locks: the mortise lock with electronic lever control and the latch pullback mortise lock. Both allow remote keyless access and control access and egress where applicable. These locks can be purchased modified, factory modified or, in some instances, modified onsite using field install kits. The electrification uses continuous duty solenoids that are designed to run cooler for continuously powered applications. Electrified mortise locks can be powered 12/24 VDC/AC.

Command Access Technologies manufactures and modifies electrified door hardware, related products and accessories. They modify cylindrical locks, mortise locks, trim, and storefront and architectural exit devices. In addition to factory modification, they manufacture electrification products that locksmiths use to modify exit devices at the jobsite. These field install kits are available with solenoid or motor driven latch pullback mechanism. Exit devices that can be modified include rim, surface vertical rod, concealed vertical rod and mortise models. Contact the factory for an up-to-date list of modification services including UL Listed products.

For example, Von Duprin 33/35/98/99 exit devices are available as exit device modification, new devices that have been electrified. Customer owned Von Duprin exit devices can be shipped to Command Access for electrification. They can be field modified by a locksmith. Not only can the above models be modified, but fire rated Von Duprin exit devices can also be field modified.

Some exit device models can be modified using a solenoid only or motor only; others can be modified both ways. Here are a few points to consider if there is a choice.

  • A Command Access solenoid equipped with the PM200/PM300 Power Booster needs a power supply that compensates for the higher power needs up to 2 Amps @ 24VDC and approximately 250mA holding.
  • A motor has low surge current draw that can be operated on a one Amp or greater 24VDC power supply drawing 125mA holding.
  • A solenoid provides an audible sound when powered indicating access has been granted.
  • Motorized exit devices are quieter, operating at almost the same speed as a solenoid.
  • If there is a small amount of pre-load on the latch, a motor provides more efficient retraction than a solenoid.
  • A motor provides a more efficient method of electric dogging.

In addition to providing latch pullback exit devices, Command Access Technologies offers available components including Request-to-Exit (REX) also known as Authorized Egress and Latchbolt Monitor (LBM). For some exit devices, factory modification is required.

Keeping exit devices in adjustment can be a daunting task, especially for vertical rod exit devices. Effective August 1, 2014, Command Access Technologies has equipped all Von Duprin motorized exit devices and modifications with the “push-to-set” (PTS) and the new MM3 module. This patent pending technology enables making adjustments to a modified Von Duprin Exit Device without any disassembly or physical changes to the latch mechanism. Here are the three step instructions:

Step 1. Press the device pushpad to the desired setting. This can be fully depressed or less than fully depressed.

Step 2. While depressing the pushpad, activate the device (i.e. present the credential to the reader) .

Step 3. Keep pad depressed and the device will beep six times. After the beeps have stopped, release the pad and the adjustment is complete.

If not to your liking, repeat the three steps.

Cylindrical Lever Locks

Command Access sells modified cylindrical lever locks from Best, Cal Royal, Command Access, Corbin Russwin, Sargent and Schlage. Depending upon the manufacturer, the locks are available in the Storeroom, Classroom or clutch operated Storeroom functions. Modified locks are available with different trim and finishes. Command Access will electrify specific models. Field install kits are not available. Cylindrical locks can be ordered with REX. Field install REX Kit is available.

Cylindrical locks can be ordered or modified as electrically locked (EL) or electrically unlocked (EU). The latch can be retracted by key outside or lever inside. In the Fail Safe operation, when power is removed, the outside lever can retract latch. Inside lever is always free for immediate egress. For Fail Secure operation, power is required to electrically unlock the outside lever. The latch can be retracted by key outside or inside lever. Inside lever is always free for immediate egress.

The operating voltage of the modified cylindrical locks is 12 or 24VAC/DC (+ 10%). The 12V solenoid draws 250 mA and the 24V draws 150 mA. The solenoid coil resistance is 49 Ω @ 12V and 159 Ω  @24V. The power consumption is three watts @ 24V.

Mortise Locks

Modified mortise locks come in two versions: electrified lever control mortise locks and latch pullback mortise lock. The electrified lever control mortise locks are available as complete locks that include trim, chassis only or locks sent to Command Access for modification. There are no field installation kits. Brands modified include Accurate, Arrow, Baldwin, Best, Cal Royal, Corbin Russwin, DORMA, Emtek, Falcon, FSB, Omnia, Sargent, Schlage and Yale. Optional switches include REX, DPS, LBM, DBM, SLM and SCM. For more information, contact the factory.

  1. Electrified lever control mortise locks are available in five functions: Electrically Locked (EL) for exterior lever only
  2. Electrically Unlocked (EU) for the exterior lever only
  3. EL for both the exterior and interior levers
  4. EU  for both the exterior and interior levers
  5. Fail Secure Classroom where the outside lever is electrically unlocked (EU). The latch can be retracted by either side lever unless the outside lever has been locked by key. Powering the outside lever permits latch retraction. Inside lever always free for immediate egress.

The operating voltage of the electrified lever control mortise locks is 12 or 24VAC/DC. The 12V solenoid draws 700 mA and the 24V draws 350 mA. The solenoid coil resistance is 18 Ω @ 12V and 69 Ω  @24V. The power consumption is eight watts @ 24V.

When energized, the Command Access Technologies LPM1 Series Latch Pullback Mortise Lock retracts the latch, allowing a push-pull condition. This solenoid powered mortise lock can be operated as momentary or continuously on to provide unrestricted or disabled access. The LPM1 Series Mortise Lock can be used in conjunction with an automatic operator for hands free access and egress. The LPM1 uses a Schlage compatible mortise lock body that will retrofit existing L9000 Series trim.

The operating voltage of the electrified latch pullback mortise lock is 24VAC/DC (+/- 10%). The surge current amperage is 1.9A for 500ms@24V. Holding current draws 250 mA @ 24V. The solenoid coil resistance is 1.75 Ω. The power consumption is eight watts @ 24VDC.

Due to the added power demand, the LPM-1 Mortise Lock requires a power supply that can withstand power inrushes in excess of two Amps for up to one second. This is like running two solenoids at the same time. To compensate, the power supply must have larger capacitors, specialized fuses and specialized programming to compensate for what may appear to be a dead short.

Exit Device Trim

The Command Access Technologies Exit Device Trim (ET) Series is an alternative for latch pullback in applications where rotating the exterior lever to gain access is desired or required. This can include storefront or stairwell applications. The ET Series are available Fail Safe or Fail Secure in different mechanical functions. Brands modified include AHT, Cal Royal, Command Access, Design Hardware, Falcon, Hager, Jackson, Precision, Sargent and Von Duprin.

The continuous duty solenoids that power the exit trims require low current draw to release or engage the locking bar. A factory installed Request-to-Enter (REE) switch is available. Command Access Technologies does not offer Exit Device Trim ET Series field install kits.

Support Components

To minimize the power requirements necessary for modified door hardware, Command Access Technologies has developed support components for their products and other manufacturers to operate together. These include the PM300 Series Power Boost Interface Modules and the two models of the Current Reduction Units, the CRU2 and the CRU2i.

When energized by a 24VDC power source, the PM300 Series Power Boost Interface Modules provide a local high current surge. When the PM300 is installed within an exit device equipped with a solenoid equipped latch pullback or in the hinge jamb directly adjacent to the exit device, the high current surge is sufficient to retract the latch. The PM300 connects between the latch-pullback exit device solenoid circuit and the power supply.

The patented PM300 Power Booster Module allows a solenoid-driven latch pullback equipped exit devices to be used with most 1.5 Amp or greater, 24VDC, non-switching power supplies. Four PM300 Series models are offered: the PM300 (looking for 24VDC filtered and regulated), PM300D (½ second delay to accommodate two latch pullback equipped exit devices on the same circuit) PM300AC (Alternating Current), and PM300ACD (Alternating Current with a ½ second delay to accommodate two latch pullback equipped exit devices on the same circuit).

PM300 Series modules are designed to overcome temporary field conditions that make it harder for the solenoid to retract the latch. These conditions can include marginal power supply, minor binding, poorly operating door hardware mechanisms or too small gauge wire run. Note: The four models of the PM300 Series each have a switch that enables the built-in High Output circuitry. This circuitry provides a maximum power boost.

Installing a PM300 Series Module adjacent to the solenoid driven latch pullback equipped devices increases wire runs while decreasing the gauge required. The maximum wire runs with a PM300 is 700 feet with 18 gauge wire, 1000 feet with 16 gauge wire, 1250 feetwith 14 gauge wire and 1500 feet with 12 gauge wire.

The CRU2 and the CRU2i are current reduction modules for low voltage electric locking devices. The CRU2 operating voltage range is 12 to 30VDC to manually limit the current draw necessary for 12 or 24VDC solenoid powered locking devices. When initially powered, full current is provided to actuate the solenoid. Once actuated, the CRU2 limits the current to allow the solenoid to run cooler while delivering sufficient power to remain actuated. The CRU2 is equipped with a manual adjust potentiometer, permitting fine tuning in the field. Once adjusted, the CRU2 provides an occasional high frequency current boost to ensure the solenoid is actuated. Maximum amperage is 1.0A.

The CRU2i is a 12 volt auto sensing module that converts 12 to 30VDC to efficiently power a 12 volt solenoid. This microprocessor equipped module makes available the appropriate startup current and adjusts to holding current once the solenoid is actuated. The CRU2i provides an occasional high frequency current boost to ensure the solenoid is actuated. Maximum amperage is 1.0A.

Command Access Technologies warrants that its products are free from defects in workmanship and material under normal use and service.For more information, contact your local locksmith distributor or Command Access Technologies, 22901 La Palma Ave, Yorba Linda, CA 92887. Telephone: 888-622-2377 .Web Site: www.commandaccess.com. In Canada, 2261 E Royal Windsor Road, Mississauga ON L5J 1K5. Telephone: 855-823-3002.