Controlling Access With Interlocks and Mantraps

Interestingly, unlike delayed egress and similar special locking arrangements, interlocks which may have a negative impact on the life safety characteristics of an opening are not clearly referenced by Life Safety and Building Codes. Be careful to obtain approval from the authorities having jurisdiction (AHJ) for your installation and be aware that there may very possibly be more than one AHJ involved.

Door control systems should be easy for management to control and end-users to understand and navigate. The door control system should also be safe. The use of visual lock status indicators will help management and users know the locked status of every door. As individuals negotiate the labyrinth you’ve created, Red and Green go-no-go lights will help them transgress area with minimum frustration and confusion.

Remote controls and emergency overrides will allow immediate intervention should the situation require.

Since your system will be controlling movement in both directions, an interface with the premises fire alarm may be required, and provisions for interfacing should be included in your design and specification.

Dortronics 4300

The Dortronics 4300 Series 2-Door interlock features two powered relay outputs for direct connection to locks and traffic lights, if used. It may be easily configured during installation for locked, unlocked or locked-unlocked operation by means of jumpers. An optional remote connection provides for override of one or both door locks by remote console, panic switch or similar actuator.

The standard 4300 series controller comes mounted in a NEMA enclosure. The standard configuration includes a 12 or 24 VDC (user selectable) 4 Amp power supply with fire alarm interface. A signal from an external fire alarm (normally closed dry contact) will cause the power supply fire alarm relay (FAR) interface relay to de-energize, cutting low voltage power to all door locks, LEDs, sounders and the PLC. The power supply manual shipped with the system has additional details.

• Power connections are made at the factory.
• Door switch contacts must be closed when the door is secure. Twisted pair wiring – AWG gauge 22 or larger is recommended.
• Door unlock time is determined by an external device, typically a card reader, motion sensor, pushbutton or remote console. Only normally open dry contacts should be used. Do not apply voltage to a 4300 input.
• Maglocks and strikes are connected to the powered outputs directly. Both powered outputs are fused. LED indicators to indicate lock status may be wired in parallel.
• LED and incandescent indicator lights, typically red to show a locked or inaccessible condition and green to show an unlocked or freely accessible condition, may be connected

The 4300 controller offers an optional lock override function. If this function is required, it must be specified when the controller is ordered. Remote lock override terminals may be connected to a set of dry contacts. On closure, the associated door lock relay will energize, unlocking the door bypassing the interlock function. To release both doors by a single set of contacts, wire the Remote inputs in parallel. This is separate and in addition to the FAR on the power supply that kills power to the locks and controller in the event of a fire alarm condition.

Building codes vary by location. The installer is responsible for understanding and working in compliance with all local codes and regulations as defined by the governing authority.

Dortronics 4700

The 4700 series Programmable Logic Controller is an economic way to control up to four interlocked doors. The controller logic sequences simultaneous requests for access and monitors unsecured doors to maintain the highest level of security at all times.

The Dortronics 4700 is suitable for air locks or security mantraps, with up to four normally unlocked doors or three normally locked doors. The controller may also be customized to control automatic door openers and provide timing and logic sequences for biological wash-down controls. Typical configurations provide outputs for traffic lights, forced doors and an emergency panic release input.

It is compatible with any access control system. The request for access input recognizes any normally open dry contact.

The 4700 series PLC controller is paired with a heavy duty 4-amp power supply that includes a Fire Alarm connection for emergency egress and provides power to operate the maglocks and electric strikes and traffic lights. An alarm output is also provided.