CONCEALED DOOR LOOP
To complete the electrical connection between the jamb and door, a power transfer system is required. For this installation, a Concealed Door Loop (CDL) was chosen. The stainless steel CDL is a flexible armored conduit designed to transfer low voltage power from the source through the jamb and door to the locking device. Because it is not a hinge, the CDL can accommodate larger gauged wires, up to an eight wire-18 gauge jacketed cable. The inner diameter of the conduit is .268”.
When the door is closed, no part of the Concealed Door Loop is visible. When the door is open, all that is seen is a short conduit and two end caps. The CDL can be mounted in any position along the edge of the jamb and hinge side of the door. The CDL can even be installed onto a door and jamb equipped with a continuous hinge. For this installation, the CDL will be mounted through the center butt hinge.
Note: Because the CDL is not easily seen, there can be little concern for finish in order to accommodate the door hardware.
To complete the installation, the Concealed Door Loop had to be installed, the wire run from the power supply to the mortise lock and the wire run from the momentary switch to the mortise lock.
The Concealed Door Loop was installed through the middle butt hinge. Five-eighth inch diameter holes had to be drilled through each leaf of the middle butt hinge for the rounded ends of the flexible armored conduit. To ensure good alignment of the holes through each leaf, the screws were removed from the door leaf. One screw was removed from the jamb leaf and the door leaf was closed against the jamb leaf. Then a longer screw went through the door leaf, into and through the jamb leaf and secured the two leafs against each other.
The end cap is then positioned onto the leaf in an unobstructed position. A center punch was used to locate the center for the end cap hole. Try to avoid drilling through any of the screw holes. Once the position is determined, drill a 5/8” diameter hole through both leaves and into the jamb frame. Remove the screw securing the leaves. Secure the leaf to the door edge.
To provide room for any movement of the flexible armored conduit as the door is closed, drill a 5/8” diameter hole three inch deep through each leaf into the door core and the jamb. This way as the door is closed, there will be sufficient room for the conduit. Use a vacuum to remove any debris from the drilled holes. Use a de-burring tool to remove any sharp edges.
Prepare the butt hinge for Concealed Door Loop end caps. Position the end caps into the drilled holes. Adjust one so the mounting holes are vertical and the second horizontal. Mark the positions. The end caps must be positioned in this fashion, as the screw head must not contact each other.
Drill the mounting holes using a 3/32” diameter bit. Tap the drilled holes using a 4-40 tapered tap. Clean out the drilled holes to insure a clean installation.
At this time, run the wiring from the power supply through the wall and out of the 5/8” diameter hole in the jamb. Slide the wire through the Concealed Door Loop and into the door’s raceway out the mortise pocket. Leave sufficient wire.
Install the Concealed Door Loop using the supplied four Phillips Head screws. Open and close the door to be certain the loop retracts into the jamb and door core.
The final step is to wire the electrified mortise lock. Two wires, one red (positive) and one black (negative), power the solenoid. Two wires will be run from the momentary switch in the conference room to the Request to Exit switch in the mortise lock case.
The mortise lock power wires have a pigtail containing a bridge rectifier. The bridge rectifier is needed if the power supplied operate the lock is AC. For this installation, the power supply produces DC. Cut the bridge rectifier off the pigtail. Wire the mortise lock.
Test the operation of the mortise lock and the Request to Exit to be certain the power supply and lock are operational.
More and more companies will begin to or continue to incorporate electromechanical locking mechanisms. Not only do these lock mechanisms control access, but also many of the system available provide audit control, meaning the ability to not only know when someone gained access, but be able to know who gained access.
For more information, contact your local locksmith wholesaler or Command Access Technologies, 2386 East Walnut Avenue, Fullerton, CA 92831. Telephone: 888-622-2377. Fax 888-622-2302. Web Site: www.commandaccess.com
CONCEALED DOOR LOOP