Showing posts with label NFPA 72. Show all posts
Showing posts with label NFPA 72. Show all posts

Tuesday, June 1, 2021

Use Backup Power For EM Locks

Use Backup Power For EM Locks 

Access control, one of the key components of a comprehensive security solution, comes in many different varieties. Essentially there are two components, the lock (i.e. the physical mechanism keeping the door locked) and the access control system (such as a card reader, biometric reader, keypad etc, which opens the lock).
Most locks
can be set to function in one of the following ways:

Fail-safe: in the event of a loss of power supply, the lock will automatically unlock, ensuring that people can still exit through the door (safety first)

Fail-secure: in the event of a loss of power supply, the lock will automatically lock, meaning people are unable to enter (or exit) through the door (security first)

It therefore only takes a loss of power to make a fail-safe lock ineffective. Of course there can be a battery backup supply installed, but the battery will have a limited lifespan, perhaps not more than a couple of hours, which limits the time available for the power supply issue to be resolved. Fail-secure locks are therefore better for doors which require higher security, but carry greater risk for safety as there could be people trapped inside the building.

When the main power fails, many believe maglocks must leave doors unlocked.

However, battery backed up maglocks are allowed according to IBC / NFPA code. It just needs to be done properly. We examine the five critical steps for using backing up maglock power correctly:

·        Understanding Codes

·        Calculating Power Budgets

·        Factoring In Power Source

·        Connecting Power Supply Fire Alarm Loops

·        Including The AHJ

In this note, we look at what the code actually says about power backups for maglocks, where they might be illegal, and how to do it right when allowed.

Multiple Factors

When it comes to preventing your Electromagnetic locks (mag-locks) doors from being unsecured when power drops, there are three basic considerations to make:

·        Codes: Understanding the applicable codes and how they apply to a building's use of maglocks is the fundamental start.

·        Engineering: Translating those code requirements into a compliant design.

·        The AHJ: Getting approval from the relevant authority is the last, and maybe most critical aspect of the process.

Codes

Accounting for about 80% of the access control in use, mag-locks operate by an electromagnetic strip attached to the door frame which aligns with an armature attached to the door. The lock can be fail-safe (whereby the electromagnet releases the armature) or fail-secure (whereby the electromagnet attracts the armature) depending on the use and safety standards.

Surprising to many, national codes do not forbid the use of battery backed up maglocks, despite the dominant 'free egress must always be possible' theme. If codes indeed forbid battery backups, these exceptions are made at the local level. However, their use is allowed if done correctly. Take a look at these passages, covering the full scope of controlled openings regardless of occupancy code:

·        NFPA 101 (2012) 7.2.1.5.6 (Electrically Controlled Egress Door Assemblies)

·        NFPA 101 (2012) 7.2.1.6.2 (Access-Controlled Egress Door Assemblies)

·        NFPA 72 (2012) 21.9.1 Electrically Locked Doors

·        IBC 1008.1.9.9 (2012)

The fundamental relevant clause cited is:

Loss of power to the listed hardware must automatically unlock the door.

However, the clause does not prohibit the use of backup power. Any electric lock in the direction of egress shall be connected to the fire alarm system and unlock when the system is activated or when power is lost.

The local jurisdiction may have a variation of these 'model codes' that take exception to the rules, so maintaining local awareness of using maglocks or backup power to them is a crucial step, often undertaken when meeting the AHJ. (See the last section in this artical.)

Calculating Power Budgets

Knowing how long a battery will keep a maglock locked is crucial. Maglocks are typically high demand devices that can drain batteries rapidly as the current draw of maglock is continuous, unlike other lock types that only use power when unlocking.

Take this example 500 pound maglock that requires 320mA at 12 VDC or 170mA at 24VDC:

Assume a 12VDC backup system furnished with two 5 amp hour batteries that must keep four maglocked doors (two sets of double doors) energized. The locks alone consume over 1.25 amps per hour, so with a 10 amp supply, doors will fall unlocked in less than eight hours. As such, prolonged outages may still require manual security response, such as guard staff mechanically locking normally maglocked doors.

Calculating this demand is complicated by other devices that must also be powered in the access system, typically the controllers, readers, and even some RTE devices like PIR motion detectors. The total demand associated with the backup supply may quickly shave the backup power duration to mere minutes in a large system, and ample capacity is a matter of careful design.

Designing Battery Backup - Device / Door Priority

Part of designing a battery backup system may be prioritizing specific (perimeter) doors to stay locked, but leaving others (inside) unlocked when power drops. Of course, the decision must conform with facility security management plans, but in the interest of maximizing uptime for critical doors, others may need to be excluded.

Factoring In Controller Power Support

However, even if one specifies sufficient batteries, a door controller may not support passing sufficient power for the period desired for battery back up power.

Normally, the maglock will be powered by main power and power will be switched on/off by controller contacts.  However, in cases when main power fails or the access designer connects maglocks as field-powered devices, power may then supplied and routed through the controller itself. Flat out, many controller contacts are not designed or rated to deliver substantial amps for long periods.  

While card readers may draw modest amounts of power (ie: 35mA - 100mA), the controller's output relay contacts may not be rated to pass through sufficient amperage to power maglocks (ie: 125mA - 850mA+)

(Note: Later versions of eIDC32 do not include this output power limitation.)

It is because of this limitation, and the way that codes address 'direct interruption' of power to maglocks, that most maglocks are best installed using a separate linear power supply, not powered by pass-thru capacity in the controller.

Batteries vs UPS vs Generators

It is worth noting that batteries are not always the only, or even preferred method, of backup power. UPS devices or batteries, as noted in UPS Backup Power for Security Guide, are the most unitized and least expensive to deploy, but run duration is always a concern. As a result, especially in critical infrastructure or services facilities, the entire building may be backed up by a generator. In this case, the supply is generally much more substantial and runs into hundreds of amps per hour. In these situations, the run length of the backup system may simply not be a realistic problem.

Power Supply Fire Alarm Loops

The codes are clear on one engineering point: when the fire alarm activates, all power to maglock must drop. This typically is implemented by tying the linear power supply into the fire alarm via an input loop.  When the alarm is pulled, it sends a signal to the supply that it must cut power to whatever device is wired to it.

Most access panel and maglock manufacturers include these instructions, although they are typically vague on details in how to connect their components so that it happens.  In many cases, the install instructions state 'Installer must wire controller and/or power supply to stop issuing power when local fire alarm is activated', or similar. However, connection plans for doing this are not hard to accomplish if understood graphically. 

For example, take this Kisi access control knowledge base schematic that shows this common connection graphically: 

Power to the maglock is directly issued by a linear power supply, that in turn is triggered to drop power when a fire alarm is detected at the controller.  Alternatively, the power supply itself may include fire alarm input contacts instead of connecting to a door controller. As previously noted, however, this power drop may apply to every device connected to the supply: readers, controllers, RTE and more.

This may leave the door unsecured, and the main motivation of 'occupant safety' takes a clear precedence over 'building security'. Therefore, schematically planning out where each device is powered, and under what conditions backup power is supplied, should not be oversimplified.

Including The AHJ

Even after all this is done, the answer might still be "no".  If the local authority having jurisdiction, or AHJ, does not approve, the idea is dead. There are two basic reasons why local AHJs may not accept the idea:

·        First Responder Access: AHJs simply do not want any possibility that firefighters cannot enter a building because the door is locked.

·        System Malfunction: Alternatively, some AHJs refuse backed up maglocks because if the fire alarm interface malfunctions, the batteries could potentially keep the door locked and trap panicked occupants inside a dangerous building.

As a result, some areas outright forbid using backup power of these types of door locks as a matter of local exception and take any decision out of the hands of local inspectors.

Proceed Cautiously

These issues describe why maglocks are hated or deemed too difficult to work with by many. While using maglocks may be less expensive or easier to install that other types of electric locks, they are not always the best choice. If the opening design is too restrictive or costly to employ other lock types, then backup power must be supplied to keep doors locked.

Working through a code compliant design and getting approval of the AHJ become a priority for the new access system.

Before you make any decisions about what lock is best for your site, it's important to first think carefully about what your site requires in terms of safety and security, and to evaluate how risk can be reduced to ensure that security related incidents won’t interrupt your business operations.

Another key consideration is the state of the site itself: if you are adding access control to a site after its completion, it may be easier (and certainly more cost effective) to opt to use wireless locks as installing all the components and wires for mag-locks and electric strike locks will require a lot of additional time, labor and effort.

Some end-user opt for a combination of locks, installing a mag-lock and an electric strike lock on a single door to ensure that it is safe, secure and is able to accurately record movements of people in and out of the door at all times. However, in this case, it may just be simpler and more cost effective to install a wireless lock. 

If you still aren't sure what type of lock and access control system best meets your needs, feel free to get in touch with one of our experts via ssaintegrate@gmail.com. Before selecting vendor / installer check and verify they are authorized or not to execute your access control system.

Sunday, July 14, 2013

Access Control Standards Revolution Now In Progress

Access Control Standards Revolution Now In Progress 



Access control provides the ability to control, monitor and restrict the movement of people, assets or vehicles, in, out and round a building.

Access control is essential for all businesses to protect people and assets and has the added benefit of being expanded from controlling, for example, a single entrance door, to a large integrated security network. There are also huge potentials in terms of integrating other systems, such as Time and Attendance, Visitor Management, ANPR, Fire, Intruder and CCTV.

Few specifications are seen more commonly in access control than UL 294. However, aside from seeing it in print, very few understand what it means. In this note, we break apart and define this spec, describing why it is a vital part of many Access RFPs.


A Standard Defined
The scope of UL 294 covers three aspects of Access Control systems: 
  • Construction (Installation)
  • Performance
  • Operation
Essentially, the heart of UL 294 is a safety standard, where testing proves that system components can be assembled and operate reliably without hazard. In the case of access control, this is a step beyond just validating devices will not catch fire or spark - it attests that the system will not harm the safety or impede egress of those using the system.
In practical terms, this means doors will not accidentally stay locked and keep people in harm's way even during a malfunction. The UL standard subjects each labeled device to a range of testing designed to show the equipment meet relevant code expectations from:
  • NEC (NFPA 99): Requirements that each component will not create a hazard either during (recommended) install or use (Sparking, Grounding)
  • NFPA 72: Fire Code compliance, assures that controllers include interfaces with fire alarm/suppression systems 
  • NFPA 101: System devices 

A UL 294 mark is a 'extra step' the vendor has taken to 'prove' their equipment is safe, and it stands as a 'mark of assurance' when included in buying specifications that dubious equipment will not be purchased.

The Mark

While Underwriter's Laboratories offer a range of 'UL Symbols' that can be interpreted to signify different standards. In the case of UL 294, the mark looks like this:
The UL 'Security Mark' applies only to products such as intrusion detectors, burglar alarms, access control, safes, and vaults.

Performance Tests
UL 294 includes several tests that evaluate how well devices withstand damaging environments. Devices are subjected to atypical electrical, environmental, and brute force situations, including:
  • Variable Voltage
  • Variable Ambients (Environment)
  • Humidity
  • Endurance (Ruggedness)
  • Transients
  • Corrosion
  • Standby Power (Battery backup)
  • Physical Attack Toughness
Tests are performed individually and are not 'layered' or 'stacked' simultaneously as might occur in the field. The exact methodology for each test depends on the device being tested, but the resulting grade is given in four levels of security performance with Level I (lowest level security equipment) to Level IV (highest level security equipment). 

Exclusions
However, not all parts and features of an Access platform fall under the scope of UL 294. Two areas excluded from the scope include:
  • Headend Server/Database: The scope reads "The accuracy of logged data is not evaluated by this standard", and also "This standard does not apply to supplementary computer equipment that is not necessary for operation of the access control system..."
  • Intrusion Detection: Again, the scope details "Where an access control equipment and/or system incorporates the features and functions of a burglar alarm control unit, the requirements of the Standard for Proprietary Burglar Alarm Units and Systems, UL 1076, shall also apply"
This is important to note when careless specs are written that "All Access Equipment shall be UL 294 Certified", because this is inherently not possible. There will be major functional aspects outside the scope of the standard.

Large System Adoption
Especially for larger systems, UL 294 is common, including devices from: Mercury Security, C*Cure, S2, Maxxess, Sargent, etc.
However, certification is done on a component basis, and there may be gaps in a brand's portfolio. If UL 294 compliance is required in a system, every hardware component must be checked for conformity, as there is no 'system' certification.
Systems and platform intended for smaller deployments (<100 doors) typically forego the certification, because it simply is not a purchasing driver for many non-enterprise customers.

Prime Use
Regardless of the 'safety' overtures, like UL certification for surveillance equipment, 294 is primarily used to exclude non-compliant systems from specifications. UL 294 evaluation is not mandatory for Access Equipment, and many vendors forego the cost of certification especially when their offerings are not well suited for larger government, institutional, and hospital verticals where 294 is commonly cited. 
Likewise, while the mark's testing 'proves' that devices are safe, the onus remains on the field technician to install them in the correct fashion to indeed live up to the certification.

Remember once UL certification has void OEM is not responsible for any health & safety incident of your premises. UL certification void due to repairing through unauthorized service provider....etc.

NFPA 101
While NFPA 101 is comprehensive, the most relevant passages for access control include:
  • NFPA 101: 'Electrically Controlled Egress Doors' (2012: 7.2.1.5.6; 2009: 7.2.1.5.5)
  • NFPA 101: 'Releasing Devices' ( 2012: 7.2.1.5.10-12; 2009, 2006, 2003: 7.2.1.5.9 -7.2.1.5.11)
  • NFPA 101: 'Access Controlled Egress Doors' (7.2.1.6.2)
Specifically, requirements like Access Control Request to Exit (RTE), Exit Devices, and Delayed Egress foundationally conform to NFPA 101.

NFPA 72
In general, this code is the foundation of requirements that doors must release when fire alarms or smoke detectors go into alarm.

NFPA 80
Specifically, this code examines Fire Doors and how they are properly used for protection in a building. In many cases, these door types are also slated to become access-controlled openings, and the 'Locks or Latches (6.4.4)' section describes which modifications are permitted for access use without voiding their fire door ratings.

IBC: International Building Code
The IBC, published by the International Code Council, is essentially a guidebook for designing and engineering safe buildings.

If not observed directly as the authority, then whatever resulting codes that do have authority take guidance from the source.
  • ·     IBC: 'Door Operations' (2012, 2009: 1008.1.9; 2006, 2003: 1008.1.8)
  • ·       IBC: 'Sensor Release of Electrically Locked Egress Doors' (2012: 1008.1.9.8; 2009: 1008.1.4.4; 2006, 2003: 1008.1.3.4)
  • ·       IBC: 'Electromagnetically Locked Egress Doors' (2012: 1008.1.9.9; 2009: 1008.1.9.8)