Maglock Installation in Katy: When a Magnetic Lock Is the Right Call, and How to Power It

Start with the opening, not the lock

77491 is one of Katy’s post office box ZIP codes, so the businesses that use it are spread across the whole city: older brick storefronts in Old Town, office parks and medical buildings along the Katy Freeway, retail around Katy Mills, and newer centers out toward the Grand Parkway. Their doors vary just as widely, which is why we never begin a Katy maglock job by choosing a lock.

A magnetic lock earns its place where three things are true: the door is hard to electrify any other way, the space can accept a lock that releases on power loss, and anyone leaving can get out without a key or special knowledge. It is the wrong answer when an opening must stay secure through a long outage, when the building cannot provide a legal exit release, or when a surface-mounted magnet would sit in every visitor’s line of sight.

Some real patterns from Katy offices and shops:

• A medical office wants staff-only access to a back corridor. A maglock on an interior door, released by a reader outside and a sensor inside, is a clean fit.
• A retailer wants the glass entrance locked after hours by fob. A maglock can do it, but because the door will be scheduled open all day, electrified exit hardware or a strike is often the neater choice.
• A small business in an Old Town building has a solid wood door. An electric strike or an electrified lockset keeps the door secure if power fails and avoids hanging a magnet on an older frame.
• A server closet or records room must stay locked even with the power out. That is a fail-secure requirement, and no maglock can meet it.

Maglock, electric strike or electrified hardware: how they differ

Commercial maglocks are sold mostly in two strength classes: roughly 600 lb for interior traffic control and roughly 1,200 lb for perimeter and heavier-duty doors. Those figures are measured with the faces in perfect contact at full voltage. In the field both conditions slip, which is why the power design below matters more than the rating printed on the box.

Why 24 volts and cable gauge decide real holding force

Most maglocks accept either 12 or 24 V DC, selected by a jumper. At 24 V the coil draws about half the current, and less current means less voltage lost in the cable. On a large Katy office floor, where the power supply lives in an IT room far from the door, that difference is anything but academic.

Here is a worked example. 18-gauge copper has roughly 6.4 ohms of resistance per thousand feet. A 150-foot run is 300 feet of conductor out and back, or about 1.9 ohms. A typical 1,200-lb lock draws on the order of half an amp at 12 V, so the cable eats nearly a volt, close to 8 percent of the supply, before anything reaches the coil. Jumper the same lock to 24 V and it draws about a quarter amp; the loss falls under half a volt, around 2 percent. Magnetic force tracks coil current, so the 12 V lock at the end of that run holds noticeably less than its rating.

So on longer runs we set locks to 24 V, size the conductor to the distance, and measure voltage at the lock terminals with the coil energized rather than at the supply. Other power decisions we make on every Katy job:

• A dedicated lock supply. Controller auxiliary outputs are usually meant for readers. Loading two or three maglocks onto one invites brownouts that drop locks or reboot the controller.
• A fire alarm input on that supply. Lock supplies with an alarm input can drop every lock output at once when the building’s fire alarm activates, which is how the code-required release is normally carried out.
• Individually fused outputs, so a pinched cable at one door does not take the rest of the building down with it.
• Surge protection on any run that leaves the building or crosses to another one.

Katy power outages: how long should the lock hold?

A maglock that loses power releases. That is a safety feature, and it is also the thing Katy business owners ask about most after the long, storm-driven outages the Houston region has been through. The honest answer is that a battery buys hours, not days.

Standby sizing is arithmetic. Two 1,200-lb locks on 24 V at roughly a quarter amp each add up to about half an amp; four hours of standby is two amp-hours before allowing for battery age and heat, so a pair of 12 V, 7 Ah batteries wired in series is a common and comfortable choice. If the reader and controller share the supply, their draw goes into the same sum. We run the numbers from the actual lock data sheet, not a rule of thumb, and show them in the quote.

Heat matters too. Sealed lead-acid batteries in a hot equipment closet lose capacity faster than the label suggests, so we date every battery at install and put a replacement reminder in your handover notes.

What no battery can do is make a maglock fail-secure. If an opening must stay locked through a two-day outage, we plan a different lock there, or a mechanical lock that is used only when the space is empty. That second option needs care: a deadbolt thrown on a maglock door while people are still inside turns an exit into a trap, so we write a closing procedure your staff can actually follow.

An EVOTECH maglock call in Katy, start to finish

1. Survey. We look at each opening, its swing, frame, closer and daily use, and tell you plainly if a strike or electrified hardware would serve it better.
2. Power plan. Supply location, cable gauge and length, 12 or 24 V, battery standby, and the fire alarm input.
3. Itemized quote listing every door with its lock, brackets and exit devices.
4. Door prep. The closer is adjusted so the door reaches the magnet on every cycle, including when the HVAC is pushing air against it.
5. Installation. Magnet and armature aligned, cable run and labeled, exit sensor and button in place.
6. Commissioning. Voltage measured at each lock, a battery run test, exit release checks, an alarm drop test, and your schedules entered in the access software.
7. Handover. A one-page record of each door, the supply and fuse that feed it, and the battery date.

What goes into a Katy maglock quote

• How many openings, and whether any are double doors.
• The lock class and any brackets the door’s swing and frame require.
• Distance to the power supply and the path the cable takes through ceilings and walls.
• The standby time you want the batteries to cover.
• The exit release method chosen for each door.
• Tying into an existing card, fob or keypad system, or starting a new one.
• Coordination with the building’s fire alarm contractor.

The power-side mistakes we design out

• Locks on the controller’s aux output. Everything works on day one, then the controller reboots whenever a second lock energizes.
• 12 V on a long, thin run. The door passes a gentle pull test and gives way to a determined one.
• Batteries nobody tests. After a few Texas summers, a battery can read full voltage at rest and collapse under load. We load-test at install and record the date.
• A mechanical lock added later. Someone fits a deadbolt for extra security and quietly creates an exit that cannot be opened in an emergency.
• An alarm input left unwired. The supply has the terminal, nobody connected it, and the locks stay energized during a fire drill.

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