By Kent · Lock Depot Staff Writer

There is a door at the back of your building that keeps opening. Merchandise goes out it. Staff prop it with a bucket so they can smoke. You cannot lock it, because it is a required means of egress and locking it is how people die in fires. The answer is a delayed egress lock for an emergency exit door. The SDC 1511S ExitCheck is that answer with the fewest parts in it.

What a delayed egress lock for an emergency exit door actually does

A delayed egress door is not a locked door. That distinction is the legal basis for the product. Somebody pushes the device. The door does not open. An alarm sounds locally. A timer runs. When it expires the magnet drops and the door opens. Anyone who wants out gets out, standing there while a siren announces them to the whole sales floor.

It does not stop egress. It removes the anonymity and speed theft depends on. A guy with a cart full of power tools will not stand at a screaming door with a camera on him. He puts the cart down and walks out the front.

The three releases that are not optional

Three conditions drop this lock, and none are optional:

• Fire alarm. Panel goes into alarm, lock releases, for the duration.
• Loss of power. No power, no magnet, no lock. Fail-safe by physics, not programming.
• The timed cycle. Push, alarm, wait, open.

Delay length, the nuisance-delay window, and the signage are governed by your authority having jurisdiction, driven by occupancy type and occupant load. I am not printing a number of seconds here; the number that matters is the one your AHJ signs off on. Call them before you order.

Why integrated beats a maglock plus a controller

You can build delayed egress out of pieces: a maglock, a controller, a sounder, wiring, a panel with the logic in it. It works. I have also been called back to fix it.

The 1511S puts the magnet and the logic in one header-mounted housing. Fewer parts to wire: one device at the header instead of a magnet plus a controller in a closet. One thing to troubleshoot: a single unit, not a ladder and a guess between the magnet, the controller, and the wire. And the logic cannot drift out of sync with the lock, which is where the intermittent failures in split systems live.

Finishes and part numbers

We stock the single-door 1511S in three finishes:

• SDC 1511S-NA-K-V in Aluminum, finish code V, default on aluminum storefront.
• SDC 1511S-NA-K-Y in Black Anodized, finish code Y.
• SDC 1511S-NA-K-X in Dark Bronze, finish code X.

Finish letters across the family run V aluminum, Y black anodized, X dark bronze, C brass powder coat, P bright chrome, and Q dull chrome.

The option codes in the middle of the part number set the configuration. Do not guess them off a cut sheet. Tell us the application, the door count, and the monitoring, and we will confirm the exact part string. The rest of the line sits on our SDC hub.

Delayed egress versus the two things people confuse it with

A plain maglock

A standard maglock drops the instant somebody hits the request-to-exit. That is what makes it legal, and it is why it does nothing against the guy walking out with your inventory: it opens as fast as an unlocked door. For holding a door shut in a controlled-access scheme, a plain mag is right: the 1650 lb holding force SDC 1511V single magnetic door lock or the double-leaf SDC 1512V. If your problem is shrink out the back door, it is the wrong tool. More on mounting in the maglock for a door you cannot mortise.

An exit alarm

An exit alarm bolts on the door and screams when somebody pushes the bar. The door opens immediately. Nothing holds. You get notification, and a horn most casual proppers stop testing after the first week. It costs a fraction of a delayed egress install: no power run, no fire alarm interface, no AHJ conversation. If the problem is a shortcut habit, buy the alarm. We laid that case out in the Detex ECL-230 piece on stopping a propped back door.

Delayed egress is what you buy when notification has already failed, or when the loss justifies making the door physically hold. Real step up in money and scope. Spend it on purpose.

	Exit alarm	Plain maglock	SDC 1511S delayed egress
Door opens on push	Immediately	Immediately on REX	After timed hold
Local alarm at the door	Yes	No	Yes
Stops a determined theft exit	No	No	Yes, in practice
Fire alarm interface required	No	Yes	Yes
AHJ signoff required	Rarely	Yes	Yes, always
Relative cost and scope	Least	Middle	Most

The traps

Three ways this job goes wrong.

The AHJ will not permit it on that door. Delayed egress is allowed by occupancy type and occupant load, and there are doors where the answer is no. People order first and ask second. Then it sits in a box. Ask first.

Nobody wires the fire alarm interface. The lock goes up, it works, and the relay never got connected because the alarm contractor and the door contractor each assumed the other had it. Now the door holds people in during an alarm. That is non-compliant. Confirm the panel has a relay and who is landing the wire, in writing, before the ladder comes out.

The header will not take it. The header has to carry the magnet and get power to it, and the door has to close square enough for the armature to seat flat. A warped hollow metal door slammed for fifteen years is a problem you solve first. Send us a photo of the header and the door top.

What to confirm before you order

• Single or double leaf. A pair changes the part.
• Finish. Match the existing header hardware.
• Monitoring and signaling. Door status at a panel, a remote annunciator, a keyswitch reset. These drive the option codes.
• Fire alarm relay. Spare dry contact at the panel, and who lands it.
• AHJ signoff. Delay time, nuisance delay, signage wording.
• Header condition. Photo of the header and the door top edge.

Common questions

Is a delayed egress lock legal on a fire exit?

Yes, in permitted occupancies, and the AHJ decides whether yours is one. It releases on fire alarm and on power loss, which is what makes it code-recognized. Allowable delay and signage vary, so call your AHJ first.

What happens to the SDC 1511S in a power outage?

It unlocks. An electromagnetic lock holds only while energized. If you need the opening secured during an outage, that is a mechanical lock or an access-controlled latch on the other side.

Do I need delayed egress, or is an exit alarm enough?

An exit alarm is enough when the problem is behavior: shortcuts, propping, casual misuse. Go to delayed egress when notification has already failed, or when the merchandise going out justifies making the door hold. Our Detex ECL-230 write-up covers the cheaper case.

How is the 1511S different from a regular SDC maglock?

The delayed egress logic and the magnet share one housing. A plain maglock like the 1650 lb 1511V releases the instant it gets a request-to-exit signal, with no delay and no alarm. The 1511S adds the timer, the alarm, and the release logic in the same box.

Which part number do I order?

Tell us the door and we will build the string. The option codes in the middle set the configuration, and we confirm those against your application rather than guessing. Send the door count, the finish, the monitoring, and what your AHJ told you.