Choosing The Access Control Locking System

Oct. 1, 2006
Most access control articles discuss the installation of access control systems from the point of view of having already chosen the equipment.

Most access control articles discuss the installation of access control systems from the point of view of having already chosen the equipment. For this article, I decided to find an opening needing to be controlled electronically, prior to the decision making process.

With the cooperation of Security Door Controls (SDC), we will begin with the building codes, what the end-user wants and needs, the building owner’s limitations and finally the opening. NOTE: The building codes that we will be writing about are the International Building Code®, national model codes which in reality are guides whose components have been adopted by more than 45 states as well as Puerto Rico and the District of Columbia. However, state and local codes may and usually do have different criterion. Contact your local Building Department to obtain code information prior to supplying information regarding the lock hardware being considered for the job.

We will discuss the system selection process including some of the questions as well as the reasons why one component was chosen over another.

Building Code

Chapter Ten of the International Building Code® (I.B.C.), 2006 version, covers means of egress. Within Chapter Ten Means of Egress is Section 1008 Doors, Gates and Turnstiles. Within this section is 1008.1.3.4 Access-controlled egress doors described as entrance doors for the purpose of this article.

1008.1.3.4 is as follows, “The entrance doors is a means of egress in buildings with an occupancy in Group A, B, E, M, R-1 or R-2 and entrance doors to tenant spaces in occupancies in Groups A, B, E, M, R-1 and R-2 are permitted to be equipped with an approved entrance and egress access control system which shall be installed in accordance with all of the following criteria:

  1. A sensor shall be provided on the egress side arranged to detect an occupant approaching the doors. The doors shall be arranged to unlock by a signal from or loss of power to the sensor.
  2. Loss of power to that part of the access control system, which locks the doors shall automatically unlock the doors.
  3. The doors shall be arranged to unlock from a manual unlocking device located 40 inches to 48 inches vertically above the floor and within five feet of the secured doors. Ready access shall be provided by a manual unlocking device and the device shall be clearly identified by a sign that reads “PUSH TO EXIT”. When operated, the manual unlocking device shall result in direct interruption of power to the lock - independent of the access control system electronics - and the doors shall remain unlocked for a minimum of thirty seconds.
  4. Activation of the building fire alarm system, if provided, shall automatically unlock the doors, and the doors shall remain unlocked until the fire alarm system has been reset.
  5. Activation of the building automatic sprinkler or fire detection system, if provided, shall automatically unlock the doors. The doors shall remain unlocked until the fire alarm system has been reset.
  6. Entrance doors in buildings with an occupancy in Groups A, B, E or M shall not be secured from the egress side during periods that the building is open to the general public.

For our purposes, sub-subsection 1 of the International Building Code Section 10 Means of Egress requires us to have a sensor (motion detector) on the egress side of the door that unlocks the lock mechanism prior to the person coming in contact with the door.

According to sub-subsection 2, the access control system must automatically unlock the doors during a loss of power.

Sub-subsection 3 specifies that . a manual unlocking device will be located 40 inches to 48 inches vertically above the floor with signage “PUSH TO EXIT”. This can be a push pad in addition to the exit device. Depressing this unlocking device will unlock the door and the door shall remain unlocked for a minimum of 30 seconds.

In sub-subsection 4 and 5, the building in which the access control system will be installed is not equipped with an early warning system.
In sub-subsection 6, the access control system cannot be configured to deny egress by remaining locked.

REMEMBER: Always discuss the installation prior to purchasing product or beginning work with the Authority Having Jurisdiction (AHJ). Most electronic hardware manufacturers will provide assistance, ranging from spec sheets and drawings, to having a factory representative present at the meeting. When discussing a project with an AHJ, introduce yourself as representing the building owner or the tenant. This gives the AHJ reason to meet with you.

To determine the appropriate electronic access control system for this application, I contacted Security Door Controls. They agreed to provide recommendations and product specific information.

Want lists

The end user would like to control access into his unit electronically. There are only a few employees, and the owner does not need time zones or audit trail. The main purpose of electronically restricting access is to keep unauthorized individuals out. The door will be mechanically locked during non-business hours.

The owner of the building does not care, as long as two criteria are met. One, the tenant does not break any laws, rules, or codes. And two, only minimal modification can be done to the door and frame. By minimal modification, the owner means a few drilled holes, no cutouts. That’s it.

The Opening

For this article, the opening is a non-fire rated single door in a safe neighborhood. It is an exterior aluminum/glass storefront dual action door. The lock mechanism on this door is a bolt type deadlock. The closer is mounted in the floor. The jamb including the header is aluminum. The ceiling is several feet above the header and is comprised of lift out panels. There is a duplex outlet above the lift-out panels.

SDC asked a number of questions in order to determine the proper electronic access control system for this door. The questions asked included identifying the door, jamb and ceiling configuration. Knowing the wants, limitations and about the opening including the foot traffic determines the appropriate access control system for this application. An SDC Check List is included here.

Additional SDC Questions and Answers

Q: What is the frame size of the storefront opening?

A: The aluminum frame for the jamb is 4” wide aluminum. The frame widths are normally four to four and one half inches.

Q: Exactly how many employees require a proximity card and do you need to know who gained access at what time?

A: There are only 5-10 employees and there is no need for an audit trail.

The Product Choices

The choices for the lock device for this access control installation are quickly narrowed down with the owner’s limitations. The owner’s limitation is minimal modification to the door and frame. With that, the choice for the access control device is a magnetic lock.

With this aluminum frame and door, SDC recommends their 1571V EmLock®. This low current consumption (250 mA @ 12vdc or 125 mA @ 24vdc) electromagnetic lock has 1200 pounds of holding force. The SDC 1581 EmLock has 650 pounds holding force which is too low as the door could be forced open. The 1581 EmLock is designed for traffic control, not to secure a door.

The SDC 1571 EmLock comes with self-drilling and self-tapping mounting plate screws. The EmLock has a quick mount assembly, and an internal wire connection that enables easy access for troubleshooting. The magnetic lock is designed so the wires can be pulled before or after mounting the EmLock.

For this installation, an SDC Universal Mounting Bracket provides additional surface area necessary for mounting a magnetic lock onto a storefront door frame equipped with a double acting door. The Universal Mounting Bracket is predrilled and tapped for both a 4” and 4.5” wide frame.

The standard EmLock’s modular design enables the installer to configure the lock in the field to accommodate the application. A standard feature includes 12 and 24-volt input sensing. Options including relock delay timer, door status and magnetic bond sensors may all be added or replaced in the field without having to remove the lock from the frame.

In addition, if a component of the EmLock needs replacement, the entire magnetic lock does not need to be replaced. The EmLock has been designed to permit removal and replacement of most electronic components without having to replace the unit itself.

Before choosing a magnetic lock, look for the proper listing and performance specifications. To ensure minimum product quality and performance capability, the American National Standards Institute (ANSI) has adopted construction and performance standards established by the Builders Hardware Manufacturers Association (B.H.M.A.). All electromagnetic door locks must comply with several mechanical, electrical and holding force requirements according to ANSI A156.23. These performance standards also place electromagnetic door locks in three categories. SDC recommends using an ANSI Grade 1 magnetic lock as the cycle test requirement is one million, twice that of the Grade 2.

Make sure the magnetic lock is B.H.M.A. Certified. This indicates that the magnetic door lock has passed an independent pull test and a dynamic impact test for holding force and complies with all ANSI and B.H.M.A. performance criteria. This is the only certification in the industry that verifies a manufacturers' magnetic door locks holding force and ANSI compliance.

In addition, make sure the magnetic lock is listed by a reputable testing agency. This can include Underwriters Laboratory, Warnock Hersey, etc. The listings confirm the magnetic lock is safe and that it has been tested for the purpose the product was intended. As an example, minimum UL Listings for magnetic locks should include:

UL Listed: Builders Hardware and Auxiliary Lock is only required for labeled door. Although this listing is not required for this installation, we decided to include it as a future consideration for informational purposes when you do come across a labeled opening.

UL 10B Listed: Burglary Resistant Electrically Operated Door Lock. This listing indicates that UL has performed a physical attack test and the lock has passed. Look for this listing on all locks over 1200 Lbs holding force.

UL 10C “Positive Pressure Compliant” and Classified in accordance with Uniform Building Code U.B.C. “Fire Test for Door Assemblies.” This classification verifies the lock does not have negative impact on the integrity of fire rated openings. UL 10C is only required for labeled door. Although this listing is not required for this installation, we decided to include this listing as a future consideration for informational purposes when you do come across a labeled opening.

Sample City and State Listings include California State Fire Marshal and New York City. The California State Fire Marshal Listing is required for California installations. The City of New York building department Materials & Equipment Acceptance Division, MEA Listing is required for NYC installations. See the CSFM Mark example. The State of California is known as consistently setting fire life safety trends and having the most stringent code requirements in the world.

By determining the number of users, the type of credential(s) desired, and the need for audit trail, Security Door Controls recommends for this application, the SDC 950 EntryCheck™ single-door controller. This combination keypad and proximity reader is weather resistant. The SDC 950 self-contained, standalone single or dual credential reader comes standard with 10 prox cards or prox key fobs. The proximity cards use the 40 bit Wiegand format.

The SDC 950 EntryCheck can retain up to 500 cards and/or Personal Identification Codes (PIN) in non-volatile memory. The unit has three entry mode choices. They are card only, PIN Code or card, or Card and PIN Code. To restrict against unauthorized access, the SDC 950 EntryCheck has a tamper alarm with reader and PIN lockout.

All programming is accomplished at the unit using the Master code (keypad) or the programming (proximity) card. The EntryCheck has LED and audible tone that indicate programming procedures. The unlock time is adjustable; it can be set for 1-99 seconds. A time adjustable auxiliary output is included.

Note: For this application, the owner is considering having the SDC 950 EntryCheck mounted onto the interior side of the glass wall adjacent to the door as the reader has a six inch read range. Locating the 950 EntryCheck on the interior has several advantages as access can still be gained using a proximity card or fob. Additional advantages include the reader is protected against weather and vandalism.

For sensor activated egress, SDC recommends the SDC MD31D Series Request to Exit Sensor (REX) to satisfy I. B. C. requirements for 1008.1.3.4. The MD31D sensor will be mounted on the wall surface or ceiling without modification in proximity to the exterior door inside a building. The Request to Exit sensor shall provide free exit to individuals within the building without causing an alarm. The Request to Exit sensor will operate using Passive Infrared (PIR). The SDC MD31D is listed by Underwriter ’s Laboratories under UL 294-Access Control System Units, FCC Part 15,C22.2 No.205-M1983-Signal Equipment and CE.

The “U” shaped PIR coverage field is created by the eight beams produced by the SDC MD31D. The shape of the coverage field can be adjusted to provide precise target area detection. In addition, the height and angle of the PIR determines the field size and distance from the wall. For this opening, the SDC MD31D can be mounted onto the header above the middle of the door. At this position, the beam can be adjusted from approximately 1.5 feet away from the door to six feet away. At the angle closest to the door, the width of the beam is at least four feet, more than sufficient to cover our single door opening. At six feet, the width is approximately eight feet, sufficient for double entry doors.

The SDC MD31D features a one-half to 64 second relock delay controlled by three switches. When a person enters the motion detection field, the Sensor interrupts power and the Fail Safe operation mode releases the lock. The MD31D code compliant Passive Infrared Egress Detector is available in a white or black housing.

The SDC MD31D has been designed to protect against a variety of unwanted activations. The SDC MD31D uses a balanced dual opposed element detector to guard against unwanted activations caused by changes in infrared energy not associated with motion. RFI protection guards against false activations caused by radio frequency interference. There is a dual slope temperature compensation circuit that increases detection capability under high temperature conditions where the background temperature is similar to that of the human body.

As a backup against electrical problems, International Business Codes 1008.1.3.4, requires that doors shall be arranged to unlock from a manual unlocking device within five feet of the secured door. Ready access shall be provided by a manual unlocking device.

To comply with this code, Security Door Controls recommends using the SDC 413MNU Request-To-Exit Switch designed for narrow frame mount applications. This exit switch complies with national fire and building code requirements for manual releasing devices. The SDC 413MNU 1-3/4” by 1” button is clearly identified by a green sign that reads “PUSH TO EXIT”. For wall mounted applications, the SDC 423MU single gang wall mount switch assembly is recommended.

When pushing the button, the door lock power is interrupted and unlocked for 30 seconds. If the button is pushed again within the unlocked period, the 30-second timer cycle is restarted. This 35mA switch operates at 12 or 24 VDC. The 413MNU is California State Fire Marshal Listed and Enterprise Engineering Laboratory Listed.

To power the magnetic lock, reader, sensor, and exit switch, SDC recommends using the UL Listed SDC 602RF Power Supply, a one amp 12/24 VDC filtered and regulated power supply with battery backup. The 602RF has field selectable 12/24VDC output. It has an isolated battery charger that operates off a separate circuit enabling this power supply to provide one amp power.

The Class 2 Outputs on the SDC 602RF power supply indicate that conduit is not required from the power supply to the lock. Power supplies that are not Class 2 would require conduit from the power supply to the lock. Additionally, SDC UL listed Class 2 power supplies can be ordered with a six foot power cord to plug directly into a 115VAC wall outlet. This can eliminate the need for conduit for the 115VAC power supply input.

The SDC 602RF power supply is UL Listed, compliant as an Access Control Systems Unit, a Fire and Burglar Alarm Power Supply and a Releasing Device Accessory.

As an option to simplify access control, SDC recommends the SDC Timer 14-2, a seven day programmable timer with memory battery backup. This timer may be set to unlock doors for normal business hours and automatically lock doors evenings and weekends.


The installation would basically follow once the decision would be made. SDC has a stick-on template for the installing the EmLock onto the header. Because the installation is onto a four-inch wide aluminum frame and the door is double acting, there is not enough frame to support the magnetic lock.

To resolve this problem, SDC offers the Universal Header bracket part number UB11V. The UB11V is pre-drilled for the mounting holes and wire chase. This simplifies the installation of the 1571V EmLock on either 4” or 4.5” wide aluminum storefront frames. The UB11V eliminates the need for an angle bracket when mounting an EmLock onto a center hung door.

Remember: The manual unlocking device, Request-To-Exit Switch, must be mounted between 40 and 48 inches from the floor and no more than five feet from the door.

SDC web site provides information regarding the Authority Having Jurisdiction in the area you are working. You must register, however, there is no cost to determine whom and where the AHJ is located.

For more information, contact SDC, 3580 Willow Lane, Westlake Village, CA 91361. Telephone: 805-494-0622 or 800-413-8783. Web site: