Choosing between an electric strike or latch-based electronic lock and a magnetic lock seems simple until you pull cable, terminate a panel, and try to satisfy fire code. The hardware behaves differently under power, the wiring topology changes with the fail-state you choose, and the way you integrate readers, door position sensors, and request-to-exit devices decides whether the door feels smooth or fussy. After installing and maintaining dozens of doors across offices, labs, and mixed-use buildings, I’ve learned that the right choice has as much to do with wiring and environment as with brand and spec sheets.
This guide focuses on wiring differences and where each lock type excels. Along the way, I’ll fold in real job-site considerations: the path from controller to lock, how to handle power, and the pieces that turn a door into a reliable part of networked security controls.
How these locks actually hold a door
An electronic door lock that’s latch based, like an electric strike or a mortise lock with an electrified trim, uses mechanical engagement. Think of the latch capturing the strike plate. When energized or de-energized, the mechanism either releases the latch or keeps it captured. The door is still held closed mechanically even if someone leans on it. That mechanical bite matters in windy vestibules, high-pressure stairwells, or anywhere people push hard on a lever.
A magnetic lock uses a magnet on the frame and an armature plate on the door. Power creates a magnetic field, and the door holds by sheer force. When power drops, the bond releases instantly. There’s no mechanical latch involved at the point of holding, which makes install and door alignment a bigger part of the craft. A poorly aligned maglock behaves like a weak handshake. A carefully shimmed and torqued install convinces you it’s a solid slab.
Both can be secure when wired correctly. They diverge sharply in how power, control, and life-safety interact.
Fail-secure vs fail-safe, and why wiring follows that decision
Electric strikes and electrified latches can usually be ordered or field-set as fail-secure or fail-safe. Fail-secure means the door stays locked when power drops. Fail-safe means it unlocks if power fails. A magnetic lock is inherently fail-safe, because when you cut power to an electromagnet, it lets go.
That single fact drives your wiring choices. With a fail-secure strike, the lock reverts to locked on a power loss, so your controller usually energizes the strike only to grant access. With a fail-safe maglock, you constantly feed power to keep the door secure and you interrupt power to allow egress or when the fire alarm says dump.
If you’ve ever opened a control panel on a fire alarm service call, you’ve probably seen relays labeled “door holder release.” Maglocks live there conceptually. Their default safe state takes the path of power interruption, and your wiring must make that interruption guaranteed and authoritative.
Power: voltage, amperage, and path
Most common door hardware runs at 12 or 24 VDC. Electric strikes might draw 250 to 600 mA momentarily. Heavier mortise bodies and panic hardware with electric latch retraction can jump to 1.5 to 2.5 A inrush for a second or three, then settle. Maglocks list holding force in pounds, often 600, 1,200, or higher, and typical current is 300 to 600 mA at 12 VDC, half that at 24 VDC. Choose 24 VDC when you can. It halves current, reduces voltage drop over long runs, and keeps things cooler.
Two wiring habits help over time:
Keep lock power isolated from controller logic where possible. Many door controllers offer a 12 V output that tempts you to power the lock directly. That’s fine for low-draw strikes within short runs. For maglocks or ELR panic bars, use a dedicated, listed power supply with enough headroom and battery backup, then let the controller switch it via a relay.
Size wire gauge to the load and distance. For a maglock pulling 480 mA at 24 VDC over 120 feet, 18/2 is usually fine. For a panic bar that inrushes 2 A, especially at 12 VDC, step to 16 AWG or shorten the run. Undersized conductors make locks chatter or buzz, which shortens their life and yours.
When you watch a reader grant access, then the lock clicks late or weak, you’re hearing the voltage drop and the relay timing argue. A meter and a few extra minutes on wire sizing save repeat visits.
Basic control loops: how signals flow
Every controlled door has the same core pieces: a reader or credential input, a controller that decides, a lock or release device, and sensors that report status. The differences lie in whether you interrupt power or provide it, and where you place your egress devices and fire alarm interface.
With electronic door locks, particularly electric strikes, the controller often applies power for a brief time to release the latch. The request-to-exit (REX) device, typically a motion sensor inside the protected area, tells the controller someone is approaching the door, so it can unlock and suppress an alarm event.
With magnetic locks, code almost always requires a direct means of egress that is independent of the access control system. That translates into a physically wired release on the egress side that removes power to the maglock without asking permission from the controller. Often that’s a mechanical egress bar with a built-in switch, or a REX and a push-to-exit button wired to drop power through a relay. The fire alarm tie-in also removes power, typically through a dedicated listed power supply with a fire alarm input.
The strike door that behaves like a good door
On a typical office door with an electric strike, I’ll run a multi-conductor to the head for a door position switch, and another to the lock side for the strike. If the controller is nearby in a closet, I land the reader on the panel’s reader inputs, the REX on the REX input, the door contact on a supervised input, then drive the strike from the panel’s relay or a separate relay board powered by a 24 VDC supply. The strike wires are simple: two conductors for power. If the strike includes latch monitoring, add two conductors to the input loop.
That topology puts logic at the panel, not at the door. The card reader wiring sticks to shielded 22/6 or 22/8 depending on the reader’s needs. In many buildings, proper access control cabling means planning bundle paths with the electrician because power contractors will otherwise zip-tie your reader cable to line voltage and give you phantom reads. Shield drain grounded at one end, twisted pairs for data lines, and clean cable management prevent intermittent headaches.
With a fail-secure strike, a power loss means the door remains locked. Life-safety in that case relies on the mechanical egress hardware. The inside lever should always retract the latch mechanically, regardless of the lock power state. That’s the safest, cleanest experience for people.
The maglock door that never surprises the fire marshal
The cleanest maglock installations I’ve seen treat the controller as advisory. The lock power comes from a listed power supply with battery backup, sized for the number of doors and load. The power supply’s output passes through a dedicated fire alarm relay contact. When the alarm panel trips, that contact opens and drops power to every maglock in the group. Locally at each door, a push-to-exit device and a REX sensor both have authority to cut power through their own relay or by driving the power supply’s door output relay. The access controller gets signals from the REX and the door contact, but it is not the only path to egress.
This layered release is not just good practice, it’s usually mandatory under code. Local jurisdictions vary, so read the AHJ’s preferences before you order hardware. I’ve had inspectors ask for both a push-to-exit button and a REX sensor, with the PTE hard-wired to drop power and the REX wired to the controller for log and timed unlock. Others accept an egress bar with a built-in switch. Documentation taped inside the power can with a wiring diagram and breaker label earns goodwill at inspection time.
Maglocks are simple on paper, two wires for power. In the field, the accessory wiring around them is the real work: multiple release inputs, fire alarm integration wiring, and often a door contact to supervise the opening. Plan a slightly larger junction box at the head to land those terminations. Keep high and low voltage separated, even in the same enclosure, with barrier or space.
Readers, credentials, and the silent UX
From a wiring perspective, readers are straightforward. Most run Wiegand or OSDP back to the controller. Wiegand is ubiquitous and simple: D0, D1, power, ground, and sometimes LED/buzzer control. OSDP is RS-485 based, supports encryption, and is increasingly standard. When I have a choice, I run shielded 22/6 or 22/8 and wire for OSDP even if the initial controller is stuck on Wiegand. It future-proofs the door.
Where it intersects with locks is timing and feedback. A maglock needs a fraction of a second longer to fully de-energize and release pressure. If your reader or controller beeps ok then the maglock still holds for 200 to 300 ms under door pressure, users learn to push early and complain the door “sticks.” Padding your unlock time slightly, and adding a short REX delay to avoid alarms when someone swings quickly, smooths the experience.
Card reader wiring must avoid high-voltage coupling, share a common ground with the controller, and terminate shields properly. If you’re mounting a reader outdoors, stub a drip loop and seal the backbox. Corrosion on the ground screen is the hidden killer of long runs. For biometric door systems like fingerprint or facial readers, follow the vendor’s power guidance closely. Many draw more current and are pickier about voltage stability. I often dedicate a small 24 VDC PoE converter locally if the controller cabinet is far. If the device speaks TCP/IP, treat it as part of your IP-based surveillance setup: home-run to a PoE switch, VLAN as needed, and document the port counts. PoE access devices simplify power at the door but push you to check switch UPS capacity since a switch failure means doors fail to their default state.
Door position, request-to-exit, and the fine print that makes reports accurate
Door position switches (DPS) are cheap, low-current contacts, but their placement matters. On a maglock door, mount the DPS where the armature meets the magnet side so you get a true closed reading only when the magnet and plate are aligned. If the door flexes under HVAC pressure, choose a recessed plunger style with a little physical forgiveness.
A REX sensor over the door must be aimed to see approaching bodies without false triggering from a hallway. Mount it inside the secure area and give it a slight delay in the controller to avoid alarm floods when someone paces nearby. If code requires a push-to-exit as well, wire that button to both the power cut path and the controller’s REX input so the log shows a clean event.
Those details become important when you integrate with intercom and entry systems. A door station that calls reception can trigger a momentary unlock through the controller, and the DPS verifies the door actually opened. If the door never opened, your operator knows to call again or look at a camera.
Cameras and alarms as part of the door story
Security camera cabling for a door is best thought of as a companion run. A small turret or mini-dome over the threshold watches for tailgating and confirms identity when the intercom rings. PoE cameras simplify the head-end since you aggregate onto the same network switch as other devices, but you need to plan the switch’s UPS runtime. Doors with maglocks tied to that same UPS will release when the UPS dies. Know your battery calculations: if you promise two hours of hold time on maglocks, make sure the power supply and the UPS agree.
Alarm integration wiring shows up in two places. First, at the door controller for intrusion loops if the same contact supervises after hours. Second, at the maglock power supply’s fire input. Label both plainly. I once inherited a site where the fire alarm had been tied into the controller’s input only. During an alarm, the controller dutifully unlocked most doors, but one door’s relay failed and stayed powered. The inspector spotted it because the push-to-exit still required a press during the drill. The correction was simple: reroute the dump through the power supply, not through logic. The lesson sticks.
Electric strikes vs maglocks in specific environments
Offices with drywall corridors and standard hollow metal frames love electric strikes. You keep the hardware looking conventional, the lever inside always grants egress, and the noise profile is low. If you need to fail-secure for after-hours, a strike respects that without special egress devices. Your access control cabling stays clean: reader back to panel, strike power from a local supply, DPS and REX into the panel.
Glass doors and aluminum storefronts often push you toward maglocks because prepping the frame for a strike is expensive or structurally awkward. A maglock mounts cleanly on the header and a surface-mount armature on the top rail. The trade-off is code complexity. Plan the push-to-exit, use a listed power supply with fire release, and give the door a little anti-tamper thought since a poorly mounted armature can rattle.
High-traffic lobbies live and die by reliability. An electric latch retraction panic device paired with a mullion reader creates a familiar experience: bar pushes out, latch retracts quietly when unlocked for events, and the lock rides through door pressure. ELR demands more power and heavier gauge wire. Using a 24 VDC power supply with a timed retraction module and heavier conductors avoids that chattering latch you hear in underwired installs.
Server rooms or spaces where you want doors to stay locked on power loss point to fail-secure strikes. Pair them with a reader and maybe a keypad for dual factor. Add an interior REX and let the handle free-egress. If the area also runs on access schedules in your networked security controls, make sure your controller’s calendar doesn’t create gaps in emergency procedures. It is a bad day when maintenance schedules an unlock at the same time the fire marshal runs a drill.
Wiring topologies that save service calls
Two patterns make troubleshooting easier.
First, put a small labeled terminal strip at the door or in the frame head where the lock, DPS, REX, and any egress button land. It turns a spaghetti of splices into a clean, testable point. If you use a maglock, land the fire-drop input relay there as well with a tag on which pair returns to the power can. Future techs will thank you when a reader goes dead and they can quickly measure voltage and continuity without opening ceiling tiles across the hall.
Second, centralize power with zone labeling. If five maglocks share a power supply, label them Door 101 through 105 on the can, and mirror that in the controller’s software notes. During a fire alarm test, you can verify each door released and logged an event. When Door 103 won’t lock after a battery swap, you know which pair to meter.
For card reader wiring, I terminate in the panel with ferrules or proper crimp sleeves rather than bare strands under a screw. It keeps intermittent faults at bay. If the reader supports OSDP, use twisted pair for the differential lines and a separate pair for power. Tie the shield to ground at the panel side only, to avoid ground loops.
PoE, relays, and when to use which
PoE access devices like door controllers with integrated readers simplify small jobs. A single Cat6 brings power and data, and the controller sits at the door driving a strike or a small maglock. The convenience is real, but mind the limits. The onboard relay often handles 1 A at 30 VDC. A big maglock or ELR bar can exceed that inrush. Use the onboard relay to drive a separate power relay instead. Also check your switch’s power budget. If four doors unlock at the same time and your switch runs warm already from cameras, something will blink at the worst time.
For larger jobs, a head-end controller panel with distributed I/O creates a robust backbone. Locks get their own power supplies close to the doors, with battery backup there, not only at the head-end. Intercom and entry systems land on the network, and your IP-based surveillance setup shares structured cabling pathways but distinct VLANs. In practice, that keeps broadcast storms from taking down your readers and maintains clean QoS for video.
Safety, code, and the human factor
No amount of tidy wiring can rescue a non-compliant plan. Ask the AHJ early: do they want push-to-exit buttons on maglock doors, what signage, and what unlock timing? Some regions require the PTE to unlock immediately and keep the door released for 30 seconds. Others allow a short REX delay if it avoids nuisance alarms. If you integrate with the building alarm, verify whether the fire panel provides a dry contact you can use for power drop or if it wants to supervise the loop. Keep prints on-site.
Train facilities staff to test doors monthly. For maglocks, push the exit device and confirm the magnet drops power and the DPS reads open. For strikes, badge in, listen for smooth release, then exit with the lever. If badges feel sluggish, it’s often a power supply or a sloppy reader cable termination starting to corrode.
Pros, cons, and what decides the choice on a real job
Here’s a concise comparison that matches wiring implications to use cases.
Electric strikes and electrified latches excel where you want mechanical integrity, quiet operation, and simple egress. Wiring stays modest: low-current power plus signal lines for DPS and REX. They support fail-secure without extra egress hardware. The downside is door and frame prep, especially on glass or aluminum storefronts, and higher current for latch retraction panic hardware.
Magnetic locks shine on frameless glass and tricky retrofits where you can’t modify the strike pocket. Wiring demands more thought: constant power, positive power drop on egress, fire alarm integration, and clear code compliance. They can hum or buzz if underpowered, and a sloppy install leads to complaints. But when properly installed with a listed power supply and clean alignment, they work predictably and are easy to service.
When an owner asks which to use, I start with three questions. What should the door do during a power https://titussqrx999.lowescouponn.com/mastering-access-control-cabling-best-practices-for-reliable-installations failure? How will people egress without thinking about technology? And what does the door construction allow without turning a one-day job into a glazing and carpentry project? The wiring follows those answers.
A practical door-by-door wiring sketch
Imagine a mixed-use floor with three doors: a server room, a main office entrance, and a glass conference room.
Server room: Electric strike, fail-secure. Reader outside, lever inside. Controller in the nearby IT closet. 24 VDC power supply in the same closet. DPS on the frame, REX motion inside. Card reader wiring uses 22/6 shielded back to the controller. Strike powered through the controller’s relay, but the current is low enough that the panel can handle it. Door ties into the intrusion system after hours via the same contact. The networked security controls schedule restricts access nights and weekends, while mechanical egress stays unconditional. The wiring here is simple and robust.
Main office entrance: Electrified panic with latch retraction for day unlock, strike keeper not applicable because it’s a full-height glass door in an aluminum frame. If the frame supports it, we use an electric latch retraction device integrated into the exit bar; if not feasible, we pivot to a 1,200 lb maglock mounted at the header. Assume maglock: Dedicated 24 VDC listed power supply with fire alarm input in the nearest electrical closet. Push-to-exit button at 40 inches AFF on the interior wall, REX motion overhead, both wired to drop power locally and signal the controller. Card reader on a mullion, OSDP back to the controller. Security camera cabling brings a PoE camera view of the threshold to the VMS. During a fire alarm, the power supply drops voltage to the maglock independent of the controller. Wiring is more complex but code-clean.
Glass conference room: Aesthetics drive the choice. We use a slimline maglock with a concealed armature bracket inside the top rail. The release must be obvious, so we add a panic bar with a request-to-exit switch feeding the maglock’s power cut relay, plus a discreet button near the jamb. The intercom and entry systems tie in for ad-hoc access from reception. A small two-door controller lives above the ceiling with a PoE uplink. Battery-backed local power holds the maglock for at least 60 minutes. Voltage drop is minimal due to short runs, but the installer still pulls 18/2 for the lock and 22/6 for control. The result looks clean and behaves well during drills.
Notes on testing and documentation
Once wired, prove every path. Disconnect the controller and verify the egress path still releases the door. Pull AC to the lock power supply and confirm battery carry. Trigger the fire alarm and watch each maglock drop, then check logs in the access software for REX events and door open events. Stand at the door while someone badges, listen for lag. A meter across the lock terminals during activation tells you whether you have enough voltage under load. A surprising number of “bad locks” are fine, but their conductors are undersized or shared with too many devices.
Document what you find. A single-page diagram per door with conductor colors, terminations, and the location of splices saves hours later. Label both ends of every cable. If you pass the job to a service team, give them the IP addresses for controllers, the VLAN tags for the IP-based surveillance setup, and the breaker numbers for power supplies.
Where technology is heading and what still matters
Modern controllers speak OSDP, handle PoE, and sit comfortably on the network alongside cameras. Some readers include BLE or NFC for mobile credentials. You can centralize power or push it to the edge with PoE access devices. Those trends simplify parts of the job, but they don’t change that a door is a mechanical system governed by life-safety rules. The right wire gauge, the right relay decision, a clean path for egress, and clear documentation beat fancy features when something goes wrong at 3 a.m.
When choosing between an electronic strike and a magnetic lock, think about failure modes, doors under pressure, occupants in a hurry, and the authority of the fire system. Wire so that the safest action requires the fewest dependencies. If the door behaves correctly with the controller unplugged and the network down, you’ve built something dependable. The rest, from card reader wiring to alarm integration wiring and cameras, becomes straightforward once the foundation is right.