SECO-LARM SD-993B-SS — Electric Shear Lock Installation Manual

Installation manual for the SECO-LARM ENFORCER SD-993B-SS Electric Shear Lock and its optional SD-993S-SB (surface-mount) and SD-993S-UB (glass door U-bracket) bracket kits — a concealed shear lock for remote access and exit control on aluminum, steel, or glass doors and gates.

Overview

The SD-993B-SS is a compact electric shear lock designed for concealed installation in metal door jambs, providing approximately 1,500 lbs. (680 kg) of shear holding force via spring-loaded locking bolts and magnetic bond. It works with sliding, single-action, and double-action (swing-through) doors and gates, and can pair with SECO-LARM's SK-983A electronic keypad for keyless high-security access.

Features

• Concealed security for remote access and exit control of aluminum and steel doors or gates
• Smaller size for use with most metal door jambs
• Zinc-plated magnet and armature, aluminum anodized housing
• Works with sliding, single-action, and double-action (swing-through) doors and gates
• Use with an optional digital keypad for keyless high security
• Easily connects to SECO-LARM's SK-983A Electronic Keypad
• Spring-loaded locking bolts and magnetic bond hold doors securely with ~1,500 lbs. (680kg) shear force
• Fail-safe operation (unlocks if power is lost)
• Armature plate adjusts to compensate for gaps between door and frame

Optional Bracket Kits

• SD-993S-SB — Surface-mounting kit
• SD-993S-UB — U-bracket kit for glass doors

Technical Specifications

Important: It is the responsibility of the end user and the dealer/installer to ensure this unit is mounted in accordance with all local fire and other safety regulations. This unit is NOT fire-rated. Some method, such as a relay, must be used to ensure doors protected by this unit can be opened in case of an emergency.

Parts List

• 1x Magnet assembly, 1x Armature assembly
• 4x Spacers, 2x Springs (for vertical mounting)
• 16x Metal screws, 1x Hex wrench

Mounting Location

1. Top of door (Best) — allows flexibility against direct attacks against the door; mount close to the corner opposite the hinges.
2. Middle of door, opposite the hinges (Good) — works well in most situations; mount halfway up for greatest strength, and add extra springs to the armature assembly for vertical mounting.
3. Bottom of door (Not recommended) — dirt buildup could affect operation.

Install the magnet assembly into the door frame before installing the armature assembly into the door, since the magnet assembly needs space for wires and its recessed portion.

Installation — Cutting the Door Frame

1. Find the door center line by tracing the outside face of the closed door onto the frame, then measuring the door width to draw a parallel line; trace the center line between them.
2. Tape the door frame template to the frame, aligning its center line with the drawn center line.
3. Hollow metal door frames: cut the rectangular opening per the template, drill the four mounting holes, and install the mounting tabs with the included metal screws, then run the wires.
4. Wood door frames: rout an 11/16" (27mm) deep, 5 13/16" x 13/16" (147 x 30 mm) cavity for the magnet assembly, plus a 3/16" (5mm) deep, 5/8" x 13/16" (17 x 30 mm) hole at each end, then run the wires.

Wiring

1. Set the jumpers for the correct power supply type (12VDC or 24VDC) before connecting power — incorrect settings can damage the unit.
2. Connect power: one terminal positive, one negative (non-polarized).
3. Wire the control device (N.C. contact, relay, or keypad) into the circuit between the power supply and the lock.

Installation — Cutting the Door (Armature Assembly)

1. Determine where to mount the armature assembly so it lines up with the magnet assembly.
2. Draw the door center line between the front and back door faces.
3. Tape the door template to the door, aligning center lines.
4. Hollow metal doors: cut the rectangular opening, drill the four mounting holes, and install with the included screws.
5. Wood doors: rout a 1⅝" (42mm) deep, 5 13/16" x 13/16" (147 x 30 mm) cavity, plus a 3/16" (5mm) deep, 5/8" x 13/16" (17 x 30 mm) hole at each end.

Note: When mounting vertically near the center of the door, disassemble the armature assembly and add the two included springs to improve push-off.

Mounting the Magnet and Armature Assemblies

1. Double-check that the magnet assembly and armature assembly line up properly; make any needed adjustments.
2. Mount the magnet assembly to the door frame and the armature assembly to the door using the provided screws.
3. Use washers or metal shims as necessary to mount both assemblies flush with the surface.
4. Close the door and check the gap between the armature and magnet assembly. Using the included hex wrench, adjust the nickel-plated portion of the armature to make the gap as small as possible (min. 2mm) without interfering with door operation.
5. Apply power and test the operation.

Troubleshooting

Regular Maintenance

• Clean the contact surfaces of the electromagnet or armature plate with a soft cloth and non-abrasive, non-corrosive cleaner
• Apply a light coat of silicon lubricant to prevent rust, wiping away the excess
• Check that the armature plate is securely attached to the door yet can pivot slightly around the armature screw
• Check that the electromagnet is securely attached to the door frame

Optional Bracket Kits — Surface-Mount & Glass Door

SD-993S-SB (Surface-mount bracket kit): The magnet assembly is housed in a bracket above the door, while the armature assembly is housed in a bracket on the door itself. Includes 2x surface-mount brackets, 4x aluminum trim plates, 3x blind nuts, 3x hex screws, and 1x blind nut assembly.

SD-993S-UB (U-bracket, glass door kit): The magnet assembly mounts flush to the door frame or header while the armature assembly is housed in a bracket on the glass door. May require one or more SD-993S-SB and SD-993S-UB kits depending on the glass door configuration. Includes 2x U-brackets, 8x aluminum spacers, 4x hex screws, and 1x hex wrench. Requires a minimum 2mm gap and 7mm clearance.

Warranty

Warranted against defects in material and workmanship for one (1) year from date of sale to the original consumer customer. SECO-LARM's obligation is limited to repair or replacement of defective parts, transportation prepaid to SECO-LARM. Void if damage results from misuse, abuse, neglect, unauthorized repair/alteration, or faulty installation.