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Katy, TX · Our home base · Locks, power supplies, diagnostics
Low-Voltage Access Control in Katy: Matching Every Lock to Its Power
Most access control failures we trace in Katy are electrical, not software: a lock set to the wrong voltage, a supply shared with a card reader, a strike scheduled open all day on a supply sized for momentary use. EVOTECH is based in Katy, and this page explains how we match each lock to its power and how we diagnose the doors that misbehave.
Lock load and duty ratingsPower supply sizingPer-door protected outputsMeter-first diagnosticsHomes, gates and storefronts
The openings we wire most often around Katy
Katy’s building stock is young overall, but it is far from uniform:
- Retail and office strip centers along the Grand Parkway, Mason Road, Fry Road and the Katy Freeway frontage, usually with aluminum storefront entries in front and hollow metal service doors in back.
- Amenity centers in Cinco Ranch, Cane Island, Elyson and Katy’s other master-planned developments, where pool gates, fitness rooms and clubhouse doors run on schedules an HOA sets.
- Churches, daycares, clinics and private schools, which often need many exterior doors unlocked on a timetable and locked instantly on demand.
- Light industrial and warehouse space toward Brookshire and along the rail line, with heavier doors and vehicle gates.
- Older buildings around Old Town Katy, where wood doors, wood frames and existing finishes limit how cable can reach the opening.
- Homes, where wired access control is less about the front door and more about side gates, detached garages and workshops.
Because we are based here, drive time is short across most of Katy. Every job still begins with an on-site estimate, since the right hardware depends on seeing the door, the frame and the power available.
Every electrified lock is a different electrical load
| Hardware | Typical voltage | How it draws current | Fail mode | Where it fits |
|---|---|---|---|---|
| Electric strike | 12 or 24 VDC, often selectable | Only while released, unless scheduled open | Field-selectable on many models | Hollow metal service doors, interior office doors, wood doors |
| Magnetic lock | 12 or 24 VDC | Constantly, the entire time the door is locked | Always fail-safe | Glass or aluminum doors where other hardware will not fit; requires added egress devices |
| Electrified exit device with latch retraction | Commonly 24 VDC | A brief high inrush, then a lower holding current while retracted | Usually fail-secure | Main entries of churches, schools and storefronts on unlock schedules |
| Electrified mortise or cylindrical lever | 12 or 24 VDC | Low, during the energized state | Either, set at order or in the field | Wood and hollow metal doors; power reaches the leaf through a transfer hinge or loop |
| Gate operator | The operator’s own supply | The access system only closes a dry contact | Set by the operator | Pool, parking and entry gates |
Two lessons come out of that table. The idea that a fail-secure strike only draws power when released stops being true the moment someone schedules the front door unlocked from 7 a.m. to 6 p.m.; the strike then carries current for eleven hours a day and runs warm, so it must be rated for continuous duty. And latch-retraction exit devices can pull a surge several times their holding current for a fraction of a second, which is plenty to drag down a shared supply.
Sizing and splitting the power supply
A dependable system follows a handful of rules we apply on every Katy job:
- Add up the worst moment, not the average. Total every load that can be on at once, including locks held open by a schedule and exit-device inrush, then add roughly 20 to 25 percent headroom. The supply’s output rating comes from that total, not from the number of doors.
- Give each door its own protected output. A distribution board with individually fused or PTC-protected outputs means a pinched cable at one door trips one output instead of taking every door down.
- Keep lock power apart from logic power. Controllers and readers get a clean output, or a supply of their own, so a lock energizing cannot pull their voltage down.
- Suppress the coil. DC strikes and maglocks are inductive, and when current switches off they kick back a voltage spike. A diode across the coil, installed with the correct polarity, or the lock’s built-in suppression protects the controller’s relay contacts.
- Feed it from a dedicated circuit. An electrician provides the 120-volt feed, ideally a circuit nobody can switch off with the lights. Everything downstream of the supply is Class 2 low-voltage work.
- Wire the fire alarm input wherever the building has a fire alarm and fail-safe locks are used, so the supply drops lock power on alarm.
A quick sizing example. Two strikes scheduled open all day at about 0.3 amps each plus two maglocks at about 0.5 amps each come to 1.6 amps of continuous load at 12 volts. With 25 percent headroom the output needs to deliver about 2 amps, so a supply rated at 1.5 amps is undersized even though it would run any single door comfortably. Real currents come from each model’s spec sheet.
Wired access control at a Katy home: where it beats a battery smart lock
For most front doors, a good battery-powered smart lock is the right answer, and we will tell you so. Wired low-voltage access control earns its place in a few residential situations:
- Side and pool gates that need a keypad or reader and a lock stronger than anything that runs on AA cells. The electrified hardware must never defeat a pool gate’s self-closing, self-latching function.
- Detached garages, workshops and garage apartments on larger lots, where a reader at the door and a controller in the house provide a log of who entered and when.
- A video intercom at the gate, so a visitor can be seen and let in from a phone.
- Homes with in-home caregivers or regular service crews, where codes that work only on certain days beat handing out keys.
HOA architectural guidelines in many Katy communities cover visible changes to fences and gates, so we check them before choosing a keypad housing or a post location.
When a door misbehaves: what the meter usually shows
| Symptom | Most likely electrical cause | What we check |
|---|---|---|
| Reader beeps, resets or goes dark when the door unlocks | Lock and reader on the same supply output; missing coil suppression | Reader voltage while the lock energizes; diode presence and polarity |
| Strike clicks but the door will not open when someone pushes on it | Pressure on the latch beyond the strike’s preload rating, or low voltage under load | Voltage at the strike while released; door alignment, weatherstripping, HVAC air pressure |
| Strike hums loudly | An AC strike, where hum is normal, or a DC strike fed unfiltered rectified power | Supply type against the strike’s rating |
| Maglock holds weakly or lets go under a hard pull | Misaligned armature plate, dirt or rust on the faces, or low voltage | Plate alignment, face condition, voltage at the magnet |
| Doors unlock after a brief power flicker | Fail-safe hardware with no battery backup, or a controller that restarts unlocked | Battery condition, supply output during AC loss, controller restart behavior |
| Constant door-forced alarms | Door position switch gap, a sagging door, or a request-to-exit device not triggering | Switch alignment, the input state on the controller, REX coverage |
Most of these take minutes to confirm with a meter and the controller’s input status screen, which is why we diagnose before we replace parts.
What EVOTECH does on a Katy access control call
- Record the symptoms and when they occur, including whether they follow storms, schedules or power events.
- Open the power supply and read its real output voltage, the battery voltage under load, and the state of every fuse or protected output.
- Take a reading at each lock while it is powered, and at each reader at the instant its lock fires.
- Check each door mechanically: alignment, latch pressure, closer adjustment and the door position switch gap.
- Review the controller’s inputs, outputs and schedules for configuration causes.
- Explain the findings and provide an itemized quote for the repair, whether that is one diode and an output split or a new supply or lock.
What affects the price of low-voltage access work in Katy
- The lock hardware each opening needs, and whether the door or frame must be prepped or a power transfer hinge added.
- Supply capacity, distribution boards, batteries, and whether a new 120-volt circuit is required.
- New construction versus retrofit into finished walls and ceilings.
- The controller and software platform, and whether existing readers and credentials can stay.
- Fire alarm, gate operator or intercom integration.
- How many doors run on unlock schedules, which affects duty ratings and supply size.
Installation habits that create repeat visits
- Hanging every lock and the controller off one unprotected output.
- Picking the 12-volt version of a lock for a long run when the same model comes in 24 volts.
- Scheduling a strike open all day when it is rated only for intermittent duty.
- Skipping the power transfer hinge and running exposed cable to an electrified lever.
- Installing a suppression diode backwards, which shorts the output the first time the lock energizes.
- Replacing a reader that was never faulty when the real problem was voltage sag.
Ask for a Katy access control power and lock quote
Related services
Frequently asked questions
Should our locks run on 12 volts or 24 volts?
Either works when the lock, the supply output and the wire are chosen together. We favor 24 volts where runs are long or exit devices are involved, since many of those are 24-volt only; inside a compact suite, 12 volts is common and fine. Mismatches, such as a 24-volt device on a 12-volt output, cause weak or intermittent operation.
What is a power transfer hinge, and do we need one?
It is a hinge with conductors running through it, carrying power from the frame into the door for an electrified lever, mortise lock or exit device. Without one, the cable ends up in an exposed door loop that is easier to damage. Strikes and maglocks mount on the frame, so they do not need one.
Why does our card reader restart every time the door unlocks?
Usually the lock and reader share a supply output, and the lock’s draw or its switch-off spike pulls the reader’s voltage down. Moving them to separate outputs and confirming the lock has suppression typically ends it.
Can you work with our existing access control panel?
Often. We test the existing controller, supply and cable before recommending replacements, and many fixes turn out to be in the power design rather than the panel. If the platform is unsupported or cannot be updated, we explain why and quote a replacement separately.
Do you install low-voltage access control at homes in Katy?
Yes, mostly for gates, detached garages, workshops and intercom-controlled entries. For an ordinary front door, we will say so plainly if a battery smart lock is the better fit.
How quickly can you get to a Katy address?
Travel is short because we are based in Katy, but the visit date depends on current workload. Call (832) 359-2425 to set a time for an on-site estimate.
Put a meter on it before anything gets replaced
Book an on-site estimate through (832) 359-2425. We check the power, match each lock to its supply and hand you an itemized quote.
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