Specifying Electric Hinges

Sept. 1, 2006
Electric hinges are preferred over door cords because they are less exposed to vandalism

Electric hinges are used when a locking device is mounted on a moving door and power and signals must be brought off the door to the controller and house wiring. Examples of such locking devices include an electrified lockset or electrically actuated trim, electric latch retraction device or a switching device such as a REX lever or touchbar.

Electric hinges are preferred over door cords because they are less exposed to vandalism, and preferred over power transfers because they are less expensive and easier to install.

The electric hinge is typically used to replace the center hinge, or one of the center hinges on four hinge doors.

Considerations

Here are a few important considerations when specifying electric hinges.

  1. Is the hinge to be used on an exterior door?
  2. Is it a fire rated door?
  3. What architectural finish is required?
  4. What is the flange size (typically 4.5" X 4.5"; but not always)?
  5. What number and diameter of conductors are required?

You should also think through how you will get the wiring from the hinge to the device on the door, and from the hinge through the frame to the other system elements. Either and/or both of these tasks can ruin an otherwise good day.

We developed a fondness for Marray hinges on a project last year, and our love has blossomed since then as we learned of their other products and somewhat independent attitude.

We used their door loops, and appreciated the fast shipping, low price and good looks. Their door cord is not indestructible, but it is equal or better to all the others in the price range, and each one comes with a drill bit and an adhesive template.

But hey kids, we all know hinges are better. Way better.

During the 1990s, we maintained and installed ATM entry systems. Thousands of them. 24/7. The overwhelming majority of them were comprised of a card reader and controller, an electromagnetic lock, a touchbar, REX button, power supply and a DOOR LOOP. Malfunctioning touch bars and vandalized door cords kept us hopping.

Back then, hinges weren't the thing, probably because the department in the bank that specified them (new construction) was not accountable to the department responsible for keeping the ATMs working and safe (Facilities). Back then, New York City passed a law called Local Law #7 and they enforced it; we repaired 'em.

So an electric hinge is concealed and has nothing to draw attention to it, providing a relatively vandal-proof and reliable solution.

If you are doing an exterior door, you cannot use an electric hinge constructed from ferrous material. You cannot force fit an electric hinge, because they are not designed to endure physical stress, just electrical stress.

You need to be sure your hinge is electrically rated for the job you are doing. If you've never used an electrical hinge before, the wires used are relatively tiny. You must order a hinge with the right conductors for your job. For example, one popular exit device which uses electric latch retraction requires an inrush current of 16 Amps. If you do not specify the right hinge, it isn't going to work. The lock won't unlock, or you're going to damage (cook) the hinge.

MARRAY HINGES

Marray addresses these issues on its website, www.marray.com. They face off with the issue and offer a product that will do the job. And they warranty it for three years. If I'm not mistaken, the exit devices in question aren't even warranted for that long.

I have one of their hinges on my bench right now, and it is a pleasure to behold. The attention to detail and quality is terrific. It's UL listed, and their phone number is etched on it, and I will install it with confidence.

The product shown is the Marray H2+4652450; TEF2 + 4; US 26D 4.5" X4.5" 6 conductor hinge. For projects where one pair is used for power, two pairs are used for internal switches, usually a Request to Exit or Latch Monitor switch.

Marray uses special silver coated high conductivity copper stranded wire on these units. Conductors are 1 Pair Heavy duty 20 gauge with wear resistant jacketing for improved life. Two pair is 30 gauge.

A full lifetime warranty is offered on the wires on standard 5 knuckle models. Marray will repair the wires on your hinge without question for the life of the product. Choose size (height x weight), finish and weight. These are ideal for Von Duprin EL Devices where high current is needed for the solenoid and a second low amp pair is needed for the bar switch. They are UL Listed for 8 amp surge at 100,000 cycles and tested by UL with the Von Duprin EL99 Device and the PS873 Power Booster.

Marray Enterprises, Inc. has been an after market modification expert since 1995. A move to Nevada in late 2003 caused the company to incorporate under the new name of Marray, Inc.

In the past several years, through exhaustive research and analysis, Marray has shifted and grown from being not only a modifier of fine hardware, but also to being a first source manufacturer of quality hardware. Such unique products as their DOR-COR™ drilling fixture, and narrow stile electrified panic rim bars, are letting them lead the industry in price, availability, and on time delivery of top quality, unique, products.

Marray has already gained a reputation for stocking a wide variety of modified products, finishes, and material. Their web page has information on the different products and services available.

For additional customer support, Marray lists a toll free number on all products and packages.

Certifications

Marray manufactured hinges are listed with Underwriters' Laboratories of the United States. (Control No. 73WJ), All of their hinges are also UL listed 10B Fire Rated Hardware.

Marray modified electrically controlled single point locks and latch are listed with Underwriters' Laboratories by the original locking hardware manufacturer, and are under label service for the Marray modification (Control No. 90WJ) Marray Rim Panic devices are listed with Underwriters' Laboratories under Control No. 24RK.

Marray's DOR-COR™ drill fixture has been tested by ITS/Warnock Hersey for use on 20 minute fire rated wood and particle board doors.

Marray has applied for and been granted four unique patents on the way it builds electrified hinges. Their electric through wire hinges so impressed the patent examiner that their request went through as written without challenge. Their DOR_COR™ drill fixture is the first of its kind available.

Marray's straight line drill pattern for hole placement allows them to repair their hinges should the wires become damaged or torn. (Murray will do this for free — for life).

Their two wire hinge can handle 16 amps of surge current for 5 seconds. This is 1600 percent over any other standard hinge on the market. Each hinge and every modified panic bar or lock comes with proper templating.

For more information on Marray hinges, contact your local locksmith distributor or Marray Enterprises Inc., 52 Laxalt Drive, Mound House, NV 89706. Telephone: 8-00-500-1449. Web site: www.marray.com.

About the Author

Tim O'Leary

Tim O'Leary is a security consultant, trainer and technician who has also been writing articles on all areas of locksmithing & physical security for many years.