Essex delayed egress schematic
Essex SKE-34 keypad, 2x6 configuration
Essex SKE-34, 3x4 configuration
Essex thinline keypad, stainless steel
Healthcare application: delayed egress for lobby doors
It is increasingly rare to encounter a security system which is not connected by some means with a larger group of doors, be it networked or wireless. And even if there is no network connection to a door, there still may be an ‘offline’ relationship, where although management and reporting are not in real time, there is a provision for the management of card holders, uploading activity logs and alteration of system operating parameters to meet requirements.
Hybrid system designs may include certain features, but omit others. This may be due to technological limitations of a particular product, or because the device is designed to fit a particular market segment or price point.
Being able to adapt the system to closely achieve the customer’s stated requirements means you are providing custom design services that differentiate you from the rest of the pack. You are offering a scalable solution which you may be able to upgrade in the future as the client’s security requirements and skills evolve, and you are doing your job as a professional security provider.
Case Study: Healthcare
This month’s case history is a good example of value-driven system design because the solution was custom configured to the customer’s exacting, and almost perpetually revised security requirements, and it was provided to the customer in a timely and cost-effective manner.
The project involved the inner lobby door to a health care facility. During the day, a receptionist was stationed in the vestibule adjacent to the door. While her presence there represented a degree of security for the premises and the patients, there might be times when she would have to leave her station. After hours, no one was there to admit visitors and monitor for inappropriate departures.
It was determined that a delayed egress system would provide the required degree of protection against patients straying out of the door by providing staff an audible alert and permitting time for a response. The Local Authority Having Jurisdiction (LAHJ) concurred with the application.
However, this was a high traffic door with visitors and staff passing through in both directions all day long. The entry function during business hours would be covered by the receptionist. Also the receptionist could see as individuals approached the door from within the premises. But an additional means for authorized individuals to leave without involving the receptionist when she was busy or after hours was required.
I specified an Essex SKE 34S standalone keypad and a Securitron IMXDA delayed egress electromagnetic lock.
Essex Standalone Keypads
Model SKE 34S is a standalone keypad with a sealed stainless keypad housing. There are no moving parts and it is extremely durable and easy to clean. It also has several great features which enabled me to design a highly functional door control system with it and the IMXDa which also offers many features in addition to the delayed egress function.
The SKE-34 is a heavy duty self contained access control keypad with many features that make it suitable for a variety of applications and environments including residential, institutional and harsh environments. The unit has an integral Form C 2A main output relay, as well as two open collector outputs* which can operate exterior relays and be controlled in a variety of ways. It may be configured to operate at 5 VDC or 12/24VDC.
The keyboard is laser etched stainless steel piezo actuated with no moving parts, and weather/vandal resistant.
The keypad is available in a 3X4 single gang or 2X6 narrow mullion configuration.
*What is an open collector output?: In functional terms, an open collector output means that when the output is activated, it goes to ground and is able to pull enough current to operate a small load or a relay coil.
iMXDa (Integrated Movement Exit Delay Advanced) is a self-contained delayed egress solution designed to provide NFPA 101 compliant door control on doors with pre-existing latching hardware. The core of the device is a 1200 lb. Securitron electromagnetic lock with a specially designed armature mounting system which enables the installer to adjust the sensitivity of the integral movement sensor which actuates the delayed egress.
Delayed egress is used to protect patients, children and merchandise and control traffic in and out of secured areas. Applications include hospitals, Alzheimer’s facilities, dormitories, airports, child care, retail or warehouse environments and proprietary corporate environments.
The IMXDa is labor saving, streamlined and easy to maintain when compared to delayed egress systems utilizing individual components. Installation requires no alteration or replacement of existing fire-rated or non-fire-rated latching hardware reducing costs and appealing to LAHJs.
Forced/Propped Door Alarm: By installing a door position sensor to the door and connecting it to the SKE 34, I was able to use the SKE integral forced door, propped door alarm feature. The SKE has a main relay output and two additional open collector outputs which may be configured for many different applications. The forced door alarm is instantaneous and the propped door alarm is programmable for up to 99 seconds. The output resets when the door closes, but it would be easy to develop a latching circuit and then use the other open collector output to provide a manual reset of an alarm if that were required.
An open collector output means that when the output is activated, it goes to ground and is able to pull enough current to trigger a relay. When configured for forced/propped alarm, the SKE holds the output low until there is an alarm, the opposite of the other configurations. This makes sense since if the keypad loses power, it will cause an alarm on the output rather than just sit there which would be the case if it energized the relay upon alarm and there would be no voltage available. By using open collector outputs, the SKE can be smaller, and you do not pay for the dry contact outputs unless you need them.
Additional components include GRI’s 4400 Switch Series, a heavy duty surface mounted industrial grade contact. The weather resistant rugged aluminum housing and a variety of optional mounting brackets make it ideal for securing chain link gates, overhead garage doors, safes or walk-in freezer doors.
Kits include hardware, brackets and mounting instructions.
The GRI 4460 Series is a compact, nice looking and extremely rugged switch set offered with or without armored cable that looks like it belongs when installed and not added as an afterthought.
The 4460 Series switch sets are resistant to nuisance vandalism and will blend in to the friendlier and more decorative atmosphere of today’s institution.
A robust working gap and mounting versatility make the G.R.I. 4460 a top choice where good looks and adaptation to a rough environment are required.
Additional components included the Altronix RB1224 Heavy Duty Relay with LED indicator and the Safety Technology International Inc. Universal Button UB-1.