Access Control Wiring in Houston, Lock by Lock and Building by Building

What access wiring looks like in different parts of the city

If your property is a multi-tenant office on the Katy Freeway west of Beltway 8, our Energy Corridor wiring page goes deeper on fire alarm release and landlord coordination. The rest of this page applies anywhere in the city.

How each common electric lock is wired

Electric strike

A strike replaces the strike plate in the frame while the door keeps its own latch. It needs two conductors for lock power, typically 12 or 24 V DC at a few hundred milliamps. Offices usually choose fail-secure: the door stays locked without power, and the inside lever always lets people out. Many strikes are field-selectable for voltage and fail mode, and a strike set to 24 V on a 12 V supply will buzz weakly and fail to release under door pressure.

Magnetic lock

A maglock mounts on the header with its armature plate on the door. It is always fail-safe and draws current the whole time it holds. It needs the full egress package: an exit sensor, a manual button that cuts power directly, and fire alarm release. Most models also have a bond-sensor output that reports whether the armature is truly holding, which is worth wiring back so the controller knows when a door has been left ajar against the magnet.

Electrified mortise lock

The lock body inside the door is the electrified part. Current draw is low and the look is clean, but power must cross the hinge, and a request-to-exit switch is often built into the inside lever to tell the controller a departure is legitimate.

Exit device with electric latch retraction

This panic bar pulls in its own latch on command, which suits main entrances with heavy traffic. Solenoid versions draw a large inrush for a fraction of a second while retracting, far more than an ordinary lock output supplies, so they need the hardware maker’s dedicated power supply or controller. Motorized versions draw much less but still get a supply sized for them.

Gate locks

Gate-rated maglocks or heavy strikes in weatherproof housings. The hard part is not the lock but the cable path onto a moving gate leaf.

Getting power across the hinge without ruining the door

Any lock mounted inside the door leaf needs conductors that flex every time the door swings. Three standard methods do that:

• Power transfer hinge. Replaces one hinge, usually the middle one, with a hinge that has wires running through it. It is invisible once installed, but it must match the door’s hinge size and weight rating, and the number of conductors is limited.
• Electrified continuous hinge or pivot. The usual choice for heavy doors and aluminum storefronts, where a full-height hinge or a pivot carries the conductors.
• Armored door loop. A flexible steel sleeve bridging frame and door edge. It is the simplest retrofit and stays visible, and a door that opens too far can crush it.

Inside the door, a channel is bored from the hinge edge to the lock pocket. On hollow metal that is routine. On a labeled fire-rated wood door, field modification can void the label, so we read the label before any drilling and use listed hardware preparations when it applies. Older converted buildings in the inner neighborhoods often have solid wood doors of unknown history, and those get checked first.

Apartment gates and callboxes, the wiring Houston calls about most

Gated apartment communities make up a huge share of the city’s housing, and their entry systems take constant abuse from traffic, weather and moving trucks. The recurring wiring issues:

• Callboxes that dialed residents over a landline. With copper phone service disappearing, these now need a cellular or network connection. Converting one usually means a new unit and a new data path, not just a new cable.
• Vehicle gates. The gate operator moves the gate; the access system only hands it an open command through a dry contact. The operator’s safety devices stay with the gate specialist who maintains it.
• Pedestrian gates. They take the worst beating. We favor weatherproof gate locks, heavy closers, and a reader on a separate post instead of the gate leaf so a slammed gate does not shake the reader loose.
• Emergency access. Local fire code requires gated properties to give the fire department a way through, using a device the fire authority approves. Any entry system replacement has to keep that device working.
• Package and amenity rooms. These have become common controlled doors and normally share the property’s controller and credential list.

Choosing 12 V or 24 V for long runs, with the arithmetic

On large Houston sites, voltage drop settles the question. Consider a gate lock that draws 0.5 A at 12 V, located 250 feet from its power supply on 18 AWG copper. Current travels out and back, so the loop is 500 feet. At about 6.4 ohms per thousand feet, that loop is roughly 3.2 ohms, and 0.5 A through 3.2 ohms loses about 1.6 V. The lock sees around 10.4 V, a drop of roughly 13 percent, which is below the tolerance of many locks. The holding force sags and a strike may not release reliably.

Run the same style of lock at 24 V and it draws about half the current, near 0.25 A. The same cable then loses about 0.8 V, only around 3 percent of the supply. That is why we specify 24 V hardware wherever a lock is far from its supply, and why upsizing to 16 AWG is the fallback when a lock only comes in 12 V. During commissioning the reading that counts is taken across the lock terminals with the lock pulling current, never at the supply.

Materials that hold up to Houston heat, humidity and storms

• Readers rated for outdoor use, with a drip loop in the cable below the reader so water runs off the cable rather than into the back box.
• Gel-filled or sealed connectors outdoors; bare wire nuts and electrical tape corrode within a summer.
• Conduits running from outside into air-conditioned space collect condensation, so the indoor end is sealed and the run slopes away from the enclosure.
• Outdoor enclosures rated against water and placed out of direct afternoon sun where possible, because a dark box in August gets far hotter than the air around it.
• Surge suppression on reader and lock circuits at gates and detached buildings, given how often summer storms bring lightning.
• Cable rated for wet locations in any underground conduit; ordinary indoor cable breaks down when it sits in water.

EVOTECH’s approach on a Houston job

Every project starts at the openings themselves. We look at the frame, the door, the existing hardware and which way people exit, because the lock choice follows from those facts and the wiring follows from the lock. Those observations become a door schedule and a power plan: which supply feeds which locks, at what voltage, with how many hours of battery, and which outputs the fire alarm drops.

Installation follows the schedule door by door, with every conductor labeled at both ends. Commissioning is where shortcuts get caught: we measure lock voltage under load, confirm the door contact and exit signal report correctly, trigger forced-door and held-open alarms on purpose, and pull power to show how each door behaves. The owner receives the schedule, panel photos and a termination list, which is what lets any future technician, ours or anyone else’s, service the system without guessing.

Pricing variables on Houston access wiring

• The number of openings and the lock type at each; latch-retraction exit devices and transfer hinges add hardware and labor.
• Building construction: plaster, brick and missing ceiling space slow routing compared with drop ceilings and steel studs.
• Outdoor openings, gate distance and any trenching or boring.
• Callbox replacement and the data path it needs.
• How much existing cable tests good and can be reused.
• Work windows outside business hours required by the property.

We quote after seeing the site, itemized by opening, so you can phase the work if the budget calls for it.

Six wiring shortcuts we end up fixing around Houston

1. A strike left on the wrong voltage or fail setting from the factory default.
2. A latch-retraction exit device on an ordinary lock output. The output burns out, or the bar only half retracts.
3. A door loop that gets pinched because the door swings wider than planned, producing intermittent failures.
4. Indoor cable in underground conduit, or a splice buried in the ground.
5. Indoor-grade connectors at an outdoor reader, which turn green and fail by the next summer.
6. No bond sensor or door contact wired, so a propped door goes unnoticed for days.

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