life safety » Door Hardware Genius

Interconnected Locks

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Sargent 7500 Series Interconnected Lock

An interconnected lock is actually two locks that are connected by an assembly that retracts both the deadbolt and the latch simultaneously when the inside handle is turned. This is done to fulfill the life safety requirement under NFPA 101 that egress should be accomplished by one motion with no prior knowledge necessary, and at the same time provide the user with the security of a deadbolt. The same function could be provided by an entry function mortise lock, but interconnected locks are cheaper, since they are usually cobbled together out of (usually) a grade 2 cylindrical lock and a tubular deadbolt.

The history of the interconnected lock is a twisted, strange story of different companies reinventing the wheel with different distances between the centerlines, connected or separate latch/bolt assemblies with correspondingly different strike preps, and radically different hole patterns on both interior and exterior door surfaces. The end result has been many, many doors and frames prepped for locks that are now irreplaceable.

Today, preps are much more standardized.

These are some of the interconnected locks available today and the measurements of their preps:

Falcon H Series – 4 inches CTC, 1-3/4 inch hold above, 2-1/8 inch hole below
Schlage H Series – 4 inches CTC, 1-1/2 inch hole above, 2-1/8 inch hole below
Schlage S200 Series – 4 inches CTC, 1-1/2 inch hole above, 2-1/8 inch hole below
Schlage CS200 Series – 4 inches CTC, 2-1/8 inch holes above and below
Sargent 75 Series – 4 inches CTC, 2-1/8 inch holes above and below
Yale 4800LN series – 4 inches CTC, 2-1/8 inch holes above and below

Replacing any of the locks above with any of the others would not present an enormous problem.

Sargent 7500 Series Door Prep

Locking People In

August 12, 2011 access control / door hardware / Life Safety Hardware / security hardware

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I often get a request to help create a system that locks people in. People want to lock children inside a daycare center, students inside a “Time-Out” room, babies inside a nursery in a maternity hospital or patients inside, for example, an Alzheimer’s disease in-patient facility for their own good.

“Well, what if there’s a fire?” I ask.

That’s really the issue. If we are keeping them in, how are they supposed to get out in the event of a fire? Yet, except when there is a fire or other emergency that renders the building unsafe, it is in their best interest if they are kept inside.

Often, people simply want to lock people in with an electromagnetic lock or other device. Since this is certainly a violation of life safety code, any injury that may result would be uninsurable and could invite litigation.

I discuss delayed egress systems in depth in another article (click here to read). A delayed egress system is really the right way to do this, since it is actually covered in the NFPA 101A Special Locking Arrangements section of the fire safety code, but it is fairly inconvenient to use. To get out without setting off an alarm users must use some kind of bypass request to exit switch like a keypad, card reader or key switch – much less convenient than, say, simply pushing a door open via the push pad on an exit device.

The gist of a delayed egress system is that, after a short ‘nuisance’ delay, the lock sounds an alarm for fifteen seconds and then lets the person out. That means that authorities on the secured premises have fifteen seconds to get to the exit and prevent unauthorized egress.

Where unauthorized egress is not a life threatening prospect, therefore, a delayed egress system is perfectly adequate. However, when a person’s life may depend on being kept inside their care facility, a more complex solution maybe required.

A great solution for Alzheimer’s or other dementia care facilities is the WanderGuard system by Stanley. This system is designed for Alzheimer’s and other health care facilities where unscheduled patient departure is an issue, and covers other needs with fall monitoring and patient call capabilities. Patients are fitted with bracelets that serve as tracking and communication devices. As one might expect, such a system is not inexpensive and a bit on the overkill side for use in a day care center or maternity facility. To physically keep people inside the facility, the WanderGuard system is designed to interface with delayed egress locks.

I think that the WanderGuard system would be a good choice for use in maternity ward nurseries as well.

The situation is more challenging when you have a day care center or a “Time-Out” room.

I had heard that Schlage was coming out with a mechanical time out lock, but a search as of today renders only the same Time-Out Room solution: An electromagnetic lock with a momentary pushbutton. The troublesome child is forced into a room, the door is shut, and then the teacher or other disciplinarian must physically press the momentary contact pushbutton to keep the magnetic locked locked. As soon as the teacher lets go, the child is free.

As long as the button is momentary, I have no problem with this idea. Should there be a fire or other life safety emergency, even if the teacher panics and runs away, leaving the child in the Time Out Room, the child will still be able to leave the room and exit the building.

The right way to prevent the kids in a daycare center from running out of the building and into the street without permission is with a delayed egress system. True, it may be cumbersome to punch in a code on a keypad or present a proximity card for authorized egress, but delayed egress systems can be easily deactivated for periods of time, say, for drop off and pick up. A delayed egress system is more expensive than, for example, an electromagnetic lock connected to the fire alarm system for safety. But if you run the scenario of a fire in your mind, the fire alarm interface to the electromagnet malfunctions, panicked children and day care providers flinging themselves against an illegally locked door, too crazed with fear to think – suddenly a delayed egress system makes a lot more sense.

There is really only one place you can really lock someone in, and that’s in a jail or prison. Otherwise there must be some provision to let them out – for safety’s sake.

Exit Device, Panic Hardware and Crash Bar Basics

April 4, 2011 door hardware / Life Safety Hardware / security hardware

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Introduction

The terms “crash bar”, “panic hardware” and “exit device” all mean the same thing.

Precision Apex 2000 Series Rim Exit Devices by Stanley

Exit devices are used on doors in the path of egress in buildings built to accomodate numbers of people. Facilities like schools, hospitals, goverment buildings and large residential buildings all use them. Fire rated exit devices are used on fire rated doors. Most interior doors that require exit devices, especially stairwell doors, are fire rated.

Fire Rated Exit Devices

Fire rated openings require fire rated exit devices. Fire rated devices are so designated by Underwriters Laboratories. I am told that UL tests them by mounting the device on a fire rated door and setting the door on fire, letting it burn for a time, and then blasting the door full blast with a fire hose. If the door opens, the device fails the test and cannot be sold as a fire rated exit device.

Non-fire-rated exit devices are used mainly on exterior doors.

Dogging Feature

One of the chief differences between a fire rated exit device and a non-fire-rated exit device is called the “dogging” feature. A dogging feature allows the user to “dog the bar down” using a hex wrench or standard key, leaving the door unlatched. Since fire rated devices must always postitively latch, they never have a dogging feature.

Narrow Stile Exit Devices

The term, “lock stile”, refers to the part of a panel door or aluminum-and-glass storefront door onto which an exit device or other lock is installed. Many aluminum storefront doors one encounters in the world have lock stiles only 1-3/4 inches to 2 inches wide. If you need an exit device for such a door, you need an exit device for a narrow stile application.

Exit Device Types

The four main types of exit devices are:

Rim
Mortise
Surface Vertical Rod
Concealed Vertical Rod
Mid-panel

See examples of rim exit devices at:

http://www.sargentlock.com/products/product_overview.php?item_id=86

and

http://www.sargentlock.com/products/product_overview.php?item_id=57

See an example of a surface vertical rod device at:

http://www.sargentlock.com/products/product_overview.php?item_id=56

See an example of a mortise exit device at:

http://www.sargentlock.com/products/product_overview.php?item_id=59

See an example of a concealed vertical rod exit device at:

http://www.sargentlock.com/products/product_overview.php?item_id=60

Specifying Exit Devices

Exit device choice is based upon the door. As mentioned previously
if the door is fire rated, the exit device must also be fire rated.
If the door is a narrow stile door, an narrow stile application exit
device is required.

In addition, you need to know the width of the door. Exit devices
come in different lengths to accomodate different door widths, so
that the touchpad of the exit device provides the coverage required
by national and local life safety and/or fire code. Door thickness
could also be a factor, especially if you are going to need exit device
trim, that is, a lever, doorknob or thumbpiece that allows people
to unlatch the door and enter from the outside. I will discuss exit
device trim shortly.

For a pair of doors (otherwise known as a double opening, or a set
of double doors), the best choice is usually a surface or concealed
vertical rod exit device. In this case you also need to know the door
height.

It is possible to lock a pair of doors using one rim or mortise exit
device and either a vertical rod exit device or a set of flush bolts,
but these solutions (while perhaps saving a little money) present
other problems. If you use a rim device on the active door, then the
strike (the part you will be mounting on the inactive door to receive
the latch of the rim device) is called quite appropriately a “pocket-ripper”
strike, since it hangs into the opening at pretty much trouser pocket
level. Use of a mortise exit device on the active leaf eliminates
that problem, but it will not work as reliably as would two vertical
rod devices, and would save very little money.

The choice between concealed and surface vertical rod exit devices
should be a simple one. If you are having doors made, have the door
manufacturer install concealed vertical rod exit devices at their
factory. If you are installing a vertical rod device at a job site
on existing doors, then use surface vertical rods.

Concealed vertical rod exit devices are preferable because they are
protected from damage by the door. However, it is an especially skilled
installer who can install one in the field, and at that, it is a time
consuming and difficult job.

Mortise exit devices offer superior durability, and are otherwise
the best choice when retro-fitting an exit device to an existing door
that already has a mortise lock.

Exit Device Trim

The exit device goes on the inside, or interior side of the door,
and exit device trim goes on the outside. Exit device trim is available
in different functions. Below are the most common functions:

Key locks and unlocks lever handle or thumbpiece. Trim can be
left unlocked for periods of time allowing free entry.
Key retracts latch. Exit device is always locked from outside,
entry by key only. Not available on some vertical rod exit devices.
Key unlocks trim only while key is inserted. User turns key, operates
control for entry. Trim is relocked when user removes key.
Passage function: trim is always unlocked allowing free entry.
Dummy trim: trim is rigid, usable as a handle to pull the door
open when either the bar is dogged down using the dogging feature
(see above) or when the latch is retracted or the device released
by other means.

Exit Device Options

Exit devices are available with a wide variety of options that increase
their functionality. These include:

Alarm
Touchpad or latchbolt monitoring switches
Electric latch retraction
Electric dogging
Delayed egress