By Kent · Lock Depot Staff Writer

The back door at the warehouse is propped open with a fire extinguisher. Again. Somebody went out to meet the truck, or for a smoke, and the door never shut behind them. On a bad day a stranger walks in and nobody knows for an hour.

Most people answer that door with four purchases: a panic bar, a closer, an exit alarm, and a latch guard. Four line items, four installs, four things to fail, and the crew still beats it with a wedge. The Arm-A-Dor is a different shape. Exit hardware and an automatic relock in one unit, mounted on the inside face of the door, with no outside trim and no outside keyway. Nothing on the exterior to pick, drill, or pry, because there is nothing on the exterior. Start at the Arm-A-Dor hub.

How a one-piece exit device and relock works

Push the bar, the door opens, and the device re-secures itself when the door swings shut. That is the whole mechanism. Securing the door stops being a decision anybody makes, so nobody has to remember to throw a bolt or check that the latch caught. The door closes, the door is locked.

Everything a normal back door exposes to the parking lot, this one does not have. No lever, no cylinder, no keyway, no trim screws. On a typical outswing service door the exposed latch is the attack point, which is why you end up adding a latch protector against a pry attack. Exit-only hardware takes the outside off the table.

It does not close the door for you. A relock is useless on a door standing open. If the opening has no closer, or a tired one that stalls two inches short, fix that before the new hardware goes on. Same for a frame a pallet jack has knocked out of square: the door and frame have to meet clean or the relock has nothing to catch.

Read this before you order: you are not coming back in that way

The Arm-A-Dor is an exit-only device. In the base configuration there is no outside trim and no key on the outside. That is the entire security value, and the thing that surprises people: once you walk out, you are not coming back in through that door.

Think hard about who uses the opening. If the receiving guy goes to the dumpster eight times a shift and comes back the same way, this will not survive contact with him. He will prop it, wedge it, or brick it open, and you will have bought hardware that recreates your original problem. When somebody legitimately needs to re-enter, you want a panic bar with night latch trim, or an alarmed exit control device you can key back through. Our piece on the Detex ECL-230 and the propped back door covers that side.

Say it out loud to whoever signs the PO. Exit only. No way back in.

Choosing an automatic relock exit device for a back door

Alarm or no alarm

The plain versions, the Arm-A-Dor A101-001 exit device and the Arm-A-Dor A102-001 exit device, do the mechanical job and nothing else. Nobody gets back in. Nobody finds out the door opened either.

If the problem is unauthorized exit or a crew that props the door, you need an alarmed unit: the A101-002 exit device alarm, the A101-012, the A101-015, or the A102-002. A relock stops re-entry. It does not tell you the door opened at 2:40 in the morning. Only the alarm does. Where re-entry is the whole problem, the plain device is less to maintain and nothing to keep powered.

Single door or a pair

A pair of doors is a different install, not the same device bought twice. The dedicated part is the Arm-A-Dor A106-001 for double doors. Look before you assume. Plenty of dock openings called a single door are a pair with one leaf bolted shut.

Door width and the exact configuration

Width drives the part number. One unit is listed as an automatic relock with alarm for 36" doors, so the family is built around door size, not one part covering everything. There is more than one device series here too, and we confirm which fits your door.

The option suffix on the end of the part number sets the exact configuration. Tell us the door width, whether the opening is rated, and whether you need the alarm, and we will confirm the part number before you order.

Fire-rated openings

A fire door has its own rules. It has to self-close and latch every time, and the hardware on it is part of a listed assembly. Do not hang hardware on a rated opening without confirming it is approved for that use. Tell us the opening is rated before you order anything, and clear the assembly with your authority having jurisdiction. I would rather lose the sale than have you fail an inspection over a back door.

Power

Alarmed versions need power. That is a battery or a plug, and the Arm-A-Dor A107-001 plug-in AC adapter is the plug. The A107-002 adapter hardware is the mounting that goes with it.

The honest version: a battery installs faster and needs no outlet, and a battery on a back door nobody checks is dead inside a year. Your alarm is then a plastic box. If there is power at or near the opening, run the adapter and stop thinking about it. If not, put the battery on the smoke-detector schedule and keep it there.

The accessory that decides the job

If you want the rest of the building to know this door opened, that is the A103-002 RX switch kit. A local horn is loud at the door and nowhere else. The RX switch is the signal out to access control, an alarm panel, or a camera trigger, so the event lands where somebody sees it. On a site with cameras already up, that part turns a noisemaker into a logged event.

Two small parts are worth adding to the order while you are at it. The A104-001 low-profile install kit matters when the door has a closer arm, a vision panel, or trim already fighting for the same real estate. The 630-668 door decal costs almost nothing and does real work: half the propping stops once the crew knows the door is alarmed. Cheapest deterrent in the catalog.

What to measure before you call

• Door width, measured, not remembered.
• Single door or a pair.
• Whether the opening is fire rated.
• Whether power is available at or near the door.
• Whether anybody legitimately needs to re-enter through that door. Answer this one first, because it kills orders.

Send a photo of the inside face and the frame with that. If the crew turns out to need a way back in, we point you at the right exit device instead and nobody wastes a trip.

Common questions

Can I get back in through an Arm-A-Dor door?

No. In the base configuration there is no outside trim and no outside keyway, so the door is exit only. That is the point, and the reason there is nothing to attack outside. If somebody needs to re-enter there, you want different hardware.

Do I need the alarm version?

Only if you need to know the door opened. The relock stops re-entry on its own, so a plain exit device solves that with nothing to power. Pick an exit device alarm when the real issue is people going out the back or propping the door.

Does it need power?

The alarmed versions do, from a battery or from the A107-001 plug-in AC adapter. Plain exit device versions do not. Given the choice, plug it in. A battery in a door nobody inspects dies quietly.

Can I use one on a pair of doors?

Not the single-door device. A pair needs the A106-001 double-door part, a different install. Check whether your opening is really a pair with one leaf permanently bolted.

Will it work on a fire-rated door?

Only in the configuration listed for a rated opening. The hardware has to match the rated assembly. Tell us the opening is rated when you call, and clear it with your AHJ.