The electric strike was developed in the late 1800's to enable New York apartment dwellers to remotely open the locked common entrance door for their visitors. Each tenant in the building could remotely unlock the entrance door from within his or her unit.
Over the years, electric strikes have evolved to provide access control for specific types of locking hardware and applications. Today's electric strikes also monitor the position of the door and if the latch is extended against the electric strike jaw(s) and the monitoring switch.
The new Adams Rite UltraLine 7400 Series Electric Strikes meet or exceed ANSI/BHMA Grade 1 standards. The 7400 Series electric strikes use a split stainless steel jaw design that retains the lock's latch while keeping the deadlatch retracted. The jaw's swinging movements are controlled using a blocking roller assembly. This assembly blocks the jaw's arms from moving when in the locked condition. When unlocked, the blocking roller assembly tilts out, permitting the jaws to swing, releasing the lock's latch.
Having two individually controlled jaw assemblies enables a significant level of holding force. According to Adams Rite, “The UltraLine provides over 2,000 pounds of static holding force, more than twice what is required for a Grade 1 electric strike rating.”
Because the electric strike's locking mechanism tilts, the UltraLine 7400 Series can release a door that is under up to 30 pounds of pre-load. Heating and air conditioning, settling of the jamb and temporary or permanent warping of the door can create the pre-load condition.
To ensure proper alignment of the latch when locked in the electric strike, Adams Rite developed a spacer mechanism for the interior side of each jaw. Two sizes of spacers can be attached to the interior sides of the jaws in order to properly position the latch within the latch bolt pocket. The thick spacers are 3/16” thick and will be pre-installed on the electric strikes. The thin spacer is approximately 3/32” thick. Installation or removal of the spacers sets the positions of the jaws in relation to the latch. This way, the latch can be positioned to enable minimal or no fixed pre-load, and ensure the deadlatch will remain retracted when the latch is in the locked condition.
The 7400 Series electric strikes are compact, requiring only 1-1/16” overall depth. The case is approximately 3-3/8” tall by 1-3/8” wide. According to Adams Rite, the UltraLine can retrofit the Adams Rite 7000, 7100, 7500 and 7800 electric strikes.
The UltraLine solenoid can accommodate 12, 16 or 24 Volts AC or DC by using the different plug-in connectors. The current draw is shown in Chart 1.
If DC power is applied to the strike, then the unit is rated for continuous duty and can be installed as Fail Safe or Fail Secure. If AC power is applied, then the unit is rated for intermittent duty and must be installed as Fail Secure.
The 7400 Series electric strikes are field reversible -- Fail Safe to Fail Secure or vise versa.
To change the electric strike operation, the position of two Phillips screws on the back of the strike body must be moved. First, loosen the internal function screw, which is located in the middle of the case. Once loose, slide the screw towards the far end of the elongated hole and secure it. Note: If the screw is not moved as far as possible, the operation of the electric strike may not be reversed.
Next, loosen the external function screw, located under the edge of the lip. If the electric strike is equipped with a lip extension, the extension must be removed to gain access to the external function screw.
Once this screw is loosened, slide the plate beneath it towards the far end of the elongated hole and secure the screw. If setting the electric strike to Fail Safe, the jaws should swing out using your fingers. Test the operation to make sure the electric strike operation has been reversed. Check to be certain both of the screws are tight.
For the purpose of this article, the 7400 Series sample was installed into a wood jamb using the Major Manufacturing HIT-34 Series router guides for wood doors and jambs, 1/2” two flute up-shear router bit and a 5/8” outside diameter template guide. The Adams Rite 74R1 and 74R2 were installed into an aluminum jamb. As an alternative, the electric strike preparation can be completed using a sharp chisel and hammer.
We started with a wood jamb prepped to accommodate a 4-7/8” strike plate with dust box. To complete the necessary electric strike prep, we used the Major Manufacturing HIT-34, HIT-34LP1 and the HIT-34SB6. The HIT-34 was mounted onto the jamb following the vertical and horizontal centerlines of the strike opening.
The first step was to rout the opening necessary for the electric strike lip using the HIT-34LP1. Once the jamb had been routed for the lip, the next step was to rout out the opening for the electric strike body using the HIT-34SB6. The final step was to drill a hole for the wiring. For an actual installation, the wiring would have to be run for the power supply and the access mechanisms.
The Adams Rite UltraLine 7400 Series electric strike is designed to accommodate a 5/8” throw latch from a cylindrical key-in-knob/lever lock or Adams Rite 4500, 4700 or 4900 Series locks. The semi-mortised Adams Rite 74R1 electric strike is designed to operate rim mounted exit devices equipped with a 3/4” Pullman bolt. The 74R2 electric strike is designed to operate rim mounted exit devices equipped with a 1/2” Pullman bolt. The Adams Rite semi-mortised electric strikes are designed to work with rim exit devices with or without an auxiliary deadlatch.
The two semi-mortised models have a zinc/aluminum alloy mounting plate whose Ritecoat epoxy standard finishes are designed to match clear, dark bronze anodized or black anodized finishes on narrow stile aluminum glass doors and jambs.
The three faceplate sizes for the 7400 Series electric strikes are: 4-7/8" radiused or square corner, 7-15/16” radiused corner and 10-1/4” radiused corner. Faceplates are available in the Adams Rite finishes.
To accommodate different jamb sizes, the UltraLine has field applied lip extensions, which mount onto the bottom of the electric strike's lip using two Phillips head screws. Lip extension kits are available in various lengths to accommodate the distance at the jamb from the vertical centerline of the door to the edge of the frame.
The 7400 Series Electric Strikes can be installed into wood, hollow metal or aluminum jambs. They have a five-year limited warranty.
For more information, contact your local locksmith wholesaler or:
Adams Rite, 260 Santa Fe Street , Pomona , CA 91767 . Telephone: 800-872-3267. Web site: www.adamsrite.com.
Major Manufacturing, 1825 Via Burton , Anaheim , CA 92806 . Telephone: 714-772-5202. Web Site: www.majormfg.com.