By Kent · Lock Depot Staff Writer

A maglock needs its own exit release, and a wall button isn't always it

An integrator wiring a maglock onto an aluminum-frame storefront door runs into the same question every time: how does someone get out without a key, a card, or a wall-mounted button they have to find in the dark? Code requires free egress on any mag-locked door with no special knowledge or effort, and a request-to-exit motion sensor over the header can false-trip on a passerby or miss a slow-moving cart that never breaks the detection cone. The other proven answer is a touch bar mounted right on the door itself, at hand height, that a person brushes on the way out. That's what the DynaLock 6451 Series exit sensor bar is built to do.

Both devices solve the same code requirement from opposite directions. A ceiling-mounted motion sensor watches an area and hopes someone walking toward the door registers as an exit attempt before they reach the glass. A touch bar skips the guessing: it sits exactly where a hand lands on the way out, and it doesn't care whether the person is walking fast, pushing a cart, or standing still leaning on the door while they finish a phone call. On a door that gets real foot traffic, that's fewer nuisance calls back to the integrator and fewer moments where someone bangs into locked glass because the sensor didn't see them coming.

DynaLock 6451: two ways to trip it, one mechanical backup

The 6451 mounts on the push side of the door and drops maglock power the moment someone touches it. It carries dual photo-optical sensors for a light touch release, plus a built-in mechanical switch as a redundant back-up, so a dead sensor doesn't strand anyone inside. It's rated for 1,000,000 cycles, runs on 12 to 24 VAC/VDC, and terminates to a removable terminal block so a tech can pull the bar for service without stripping wire nuts off the harness. BC lists it under SKU 6451-36-US28 at the 36" size, up through the 6451-48-US28 at 48", all in a satin aluminum finish that reads as clean trim rather than an obvious add-on box.

Sizing it to the actual door, not the nearest stock size

This is where a lot of these get ordered wrong. The actual bar length runs 2" less than the door width, and the mounting hole spacing is 2-3/4" less than the door width — so a 36" door doesn't take a 36" bar, it takes a bar sized to that door's actual width minus the standard offset. Measure the door, not the rough opening, and don't round up to the next stock size hoping it'll overhang cleanly; it won't. The catalog carries 6451-42-US28 for the 42" step between the 36" and 48" sizes, which covers most single-door storefront and vestibule openings without forcing a custom cut.

All three sizes are built for the same class of door: aluminum or hollow-metal, with a 5/8" or less frame stop. If the frame stop on the job runs deeper than that, the bar won't seat right and no amount of shimming fixes it — that's a call to make before the bar ships, not after it's on the truck.

It's also non-handed, so the same part works whether the door swings left or right and whether the maglock sits on a single door or one leaf of a pair. On a pair of doors, order one bar per active leaf; the inactive leaf on a storefront pair usually carries flush bolts or an astragal instead and doesn't need its own release. Mount the bar at a comfortable push height on the door face, not buried under a push plate or a door pull, or the whole point of a touch release disappears under someone's hand reaching for the wrong hardware.

Wiring it into the maglock circuit

The 6451 is designed to work with an electromagnetic lock, and on a fail-safe maglock circuit it interrupts power to the mag the instant someone touches the bar, dropping the lock and releasing the door on the spot. That's the same fail-safe principle behind the holding-force sizing on DynaLock's 2000, 2500, and 3000 Series maglocks: the door has to release on power loss and on a deliberate exit attempt, full stop. A sensor bar is one accepted way to satisfy that free-egress requirement; it still needs to run alongside a fire-alarm interconnect on any door in the path of egress, and a facility with a door-status monitoring requirement should pair it with a lock that reports status, the way DynaLock's DSM2 and HSM2 monitor options do on the mag itself. The sensor bar handles the touch-to-exit release; it isn't a substitute for the alarm interconnect a life-safety inspector will ask about.

Common questions

Can I use one bar size for two different door widths on the same job?

No. The bar length and the mounting hole spacing are both cut to the specific door width, 2" and 2-3/4" less than the door respectively. A bar sized for a 42" door won't line up on a 36" or 48" opening.

Does the sensor bar work if the door has a deep frame stop?

Not reliably. The 6451 is built for a 5/8" or less frame stop. A deeper stop needs a different release method or a modified mount, confirmed before the hardware ships, not discovered during install.

What happens if the optical sensor fails?

The bar has a built-in mechanical switch as a redundant back-up release, so a failed sensor doesn't lock someone inside. It's a second, independent way to trip the same release.

Does the sensor bar replace the fire-alarm interconnect on a maglock door?

No. It satisfies the touch-to-exit free-egress requirement, but a mag-locked door in the path of egress still needs to drop on a fire-alarm signal. Those are two separate requirements and both have to be wired in.

Is a touch bar better than a request-to-exit motion sensor?

They solve the same problem differently, and neither is wrong on its own. A motion sensor covers a wider area with nothing to touch, but it can false-trip on nearby movement or miss someone who approaches slowly. A touch bar only releases when someone's hand actually contacts it, which cuts down on nuisance releases on a door with heavy foot traffic close by on either side.