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Electric lock & door opener: Retrofitting the locking mechanism correctly

Elektroschloss und Türöffner – Verriegelung für Drehtor, Schiebetor und Pforte nachrüsten

Daniel Schweighöfer |

Electric lock & door opener: Retrofitting the locking mechanism correctly

A gate or door that closes "somehow" is not a security concept – that's gambling. It happens all the time, especially with swing gates, sliding gates and pedestrian gates: The drive mechanism closes, but wind pressure, Play in the mechanism or a crooked stop will cause you to push the gate open again with a strong jerk. The result: trouble, damage, and in the worst case, an open property.

This editorial provides clear explanations: What is an electric lock, what is a door opener, and when do you need which system? And how do you neatly connect the locking mechanism to the control unit, code keypad, or key switch? In addition: simple checklists, typical error patterns and useful product recommendations. We advise customers daily who in the end only need a small part – or who have already bought the wrong lock. To prevent this from happening to you, let's tidy up here.

Quick check: Do I even need a lock?

You (almost certainly) need a lock if… 🔒
  • you can push the closed gate open again using hand force.
  • Wind pressure causes the gate to "work" (especially with long wings).
  • You operate a gate/door with an access system (code/finger/key).
  • You value genuine burglary protection (not just "moved in").
You might not need one if…
  • You have a mechanical lock that really engages cleanly.
  • The gate is already secured at the factory with a motor lock/drive lock.
  • Your goal runs smoothly and the stop is rock solid (no play).

Important: “The drive will hold it” is not a locking mechanism. It only refers to the motor's standby power – which is lost against wind, play, and time.

Quick update: What's currently in demand?

More access without a key

Code locks, fingerprint scanners and wireless access are becoming increasingly popular – logically: fewer remote controls, more control. If you use such a system, you need a locking mechanism at the back that actually "holds".

Relevant categories: Combination locks , Key switch , Smart Home Gate Control

Retrofit instead of buying new ✅

Many problems arise not because the gate is “bad” – but because the stop, closing point and locking mechanism were never properly aligned. That's exactly where retrofitting pays off: cheaper, faster, and often the cleanest solution.

If you're unsure: Contact us – then we'll save you from bad purchases and crafting frustration.

Terms: Electric lock vs. door opener vs. motorized lock

Door opener (electric door opener)

Classic design for doors/gates: The frame contains an opener that releases the bolt/latch. Ideal if a door mechanically “locks” and you only want to release it electrically for opening.

Electric lock (locking mechanism)

Actively locked – e.g., bolt extends/retracts or holds sash in position. Common with swing gates/sliding gates when wind load or play otherwise pushes everything apart.

Motor lock / drive lock

The drive has an integrated locking mechanism (or uses a system that actively locks the sash). Powerful – but not every system has it, and not every installation is designed for it.

Key point: If you want to solve “access” cleanly, think in 2 steps:
  • Who is authorized to open the door? (Code, key, radio, app)
  • What actually holds it closed after that? (Lock/latch)

Fail-Safe vs. Fail-Secure: What does that mean?

This is where most bad purchases happen. So let's be clear: Fail-safe means: In the event of a power failure, the lock opens/releases. Fail-Secure means: In the event of a power outage, it remains locked.

type Behavior in case of a power outage Typical application Pros / Cons
Fail-Safe opens / releases Gate, escape routes, areas where “getting out” has priority ✅ Safe in emergencies / ❗Less burglary protection in case of failure
Fail-Secure remains locked Driveway, property, storage ✅ Remains closed / ❗Emergency opening must be arranged
Motor lock depending on the system Swing gates/sliding gates with integrated locking mechanism ✅ elegant / ❗Check compatibility

Tip: If you want “access for many” + “security”, you need a clear concept for emergency opening. If you'd like, we can go through it with you: Contact

12V/24V AC/DC: Why this is important

AC vs. DC – explained briefly ⚡
  • AC = Alternating voltage (e.g. 12V AC)
  • DC = Direct current (e.g. 24V DC)
  • Many door openers/electric locks can handle 12–24V AC/DC – but not all of them.
Why it goes wrong in practice
  • Insufficient voltage at the lock → it “hums”, but does not unlock.
  • Incorrect voltage (AC instead of DC) → unreliable or continuous overheating.
  • Cable too thin / line too long → voltage drops, lock becomes temperamental.
Rule of thumb: The longer the cable and the stronger the locking mechanism, the more important Clean supply , suitable cross-section and correct control logic .

Mechanics first: Stop, play & wind load

If the mechanics aren't right, no lock will save you.
  • The closing point must be precisely hit (the bolt should not be "on edge").
  • The strike plate/stop must be stable (do not bend).
  • The piano must not "work" (play in the fitting, uneven floor).
Mini check in 60 seconds
  • Close the gate.
  • Grab the wings at the top and bottom and shake them: How much play is there?
  • Check the locking point: is the bolt centered?
  • If you notice: “pulls crooked” → first correct mechanically, then retrofit electrically.

Which locking mechanism is suitable for swing gates, sliding gates & pedestrian gates?

Application Recommendation What to look out for
Swing gate (2-leaf) Electric lock/latch on the fixed leaf or floor lock Wind load, wing play, stable stop
Swing gate (single-leaf) Electric lock + clean strike Lock position, cable protection, emergency opening
Sliding gate Depending on the system: locking mechanism/motorized lock or mechanical bolt. Closing edge, end stop, safety devices
Gate / Door Door opener (fail-safe or fail-secure depending on the concept) DIN direction, door rebate, bolt/latch, appropriate voltage

For accessories related to locking mechanisms and fittings: Swing gate operator accessories / Electric locks

Parts list: What you really need

Must-have (Basics)
  • Locking mechanism (electric lock or door opener)
  • Stable strike plate / stop
  • Clean power supply (12/24V AC/DC compatible)
  • Suitable cable cross-section + protection (corrugated conduit/spiral hose)
Nice-to-have (makes it stress-free)
  • Additional relay/relay contact if required by the control system
  • Access system: code, key or button
  • Safety: Light barrier in automatic systems
  • Clean mounting hardware (screws, brackets, dowels)

Matching accessories: Mounting hardware

Connection to control system: relays, terminals, logic

Basic principle (simply explained):
  • The control unit issues a command (e.g., “open” or “unlock”).
  • The lock requires the correct voltage (e.g. 12V/24V) – not just anything.
  • Switching is often done via a potential-free relay contact (clean & compatible).

Important: We can't blindly model every control system here. If you send us your model and target, we'll tell you directly how to do it properly: contact

Typical mistake

The lock is directly connected to a terminal that only provides a “signal” – not enough power. Result: It clicks sometimes, but not reliably.

Typical solution

Relays in between, clean power supply, correct timing logic (unlock time / delay). After that, the thing works as it should.

Integration: Code keypad, keypad, smart home

Key switch

Robust, simple, reliable – a sure thing, especially outdoors.

Selection: Key switch

Keypad lock / keypad

Perfect for multiple users. Important: clean connection (relay contact) and clear authorization.

Selection: Combination locks & keypads

Smart Home

App/automation is cool – but only if the underlying locking mechanism is stable. Otherwise, you're only controlling it "halfway".

Selection: Smart Home Gate Control

Don't forget safety: Depending on the system, automatic gates require additional safety measures – e.g., a light barrier.

View light barriers

Assembly Step 1: Installation Location & Alignment

Door/Gate (door opener)
  • The opener sits in the frame; the strike plate must fit.
  • The bolt/latch must engage easily – without force.
  • Is there play in the hinge? Fix it first, otherwise the opener will seize up and break.
Swing gate (electric lock)
  • Choose the closing point so that wind load cannot “lever” it.
  • Secure the strike plate firmly (not a flimsy, makeshift solution).
  • Plan the installation in such a way that water/dirt does not permanently get in.
Pro tip: A lock that closes “under tension” (diagonally / offset) will first make noise – and then cause problems. Take your time here, that's half the battle.

Assembly Step 2: Cable routing & protection

Cable protection outside
  • Do not leave cables hanging freely (UV radiation, water, animals, mechanical stress).
  • Use corrugated tubing/protective hose, seal penetrations.
  • Position loops/movement points so that nothing rubs.
Cross-section & length
  • Long distance = voltage drop = lock becomes unreliable.
  • If you don't want to calculate it: better to go a size "stronger" than too thin.
  • If you're unsure, just let us know, and we'll work it out for you using the data.

Assembly Step 3: Electrical Connection (Basics)

Safety first: Work on 230V electrical systems should only be carried out by qualified professionals. Period. At 12/24V it is “lower”, but you can still cause damage (and in case of doubt, fry the controller).

Here's how to do it properly 🛠️
  • Check the type and voltage of the lock (12/24V, AC/DC, Fail-Safe/Secure).
  • Identify the output at the controller (relay contact vs. supply terminal).
  • Define the switching logic (when to unlock, how long, delay).
  • Test everything first, then finalize the decision.
If you want a clear example

A typical door opener (12–24V, fail-safe) is, for example, this model: Door opener 12–24V (fail-safe)

Important: Always check compatibility with your application (door/gate/gate) and the control system.

Commissioning: Test procedure in 10 minutes

  1. Mechanical test: Does everything close easily? Does the bolt engage centrally?
  2. Voltage test: Is the correct voltage reaching the lock (under load)?
  3. Switch test: Does it unlock exactly when it's supposed to?
  4. Practical test: 20x open/close, quickly one after the other (not just 2x "that's fine").
  5. Worst-case scenario: Light pressure against the wing (simulating wind) – will it hold?

If you get stuck on test #3 or #4: don't keep pushing. Find the cause – then it will work in the long run.

Safety rules & no-gos

No-Go #1: “Somehow connected”

Incorrect voltage or output will destroy your lock or control unit. That's more expensive than a quick, proper plan.

No-Go #2: Closing point on edge

If the bolt enters at an angle, the mechanics always win in the end – and you lose time and nerves.

No-Go #3: Ignoring safety

Automatic gates need appropriate safety measures. A photocell is often the simplest starting point.

Troubleshooting: When it hums, jams, or doesn't hold.

Problem: The lock hums, but does not unlock.
  • Voltage too low (cable too long / cross-section too small)
  • Incorrect voltage (AC/DC reversed)
  • Mechanism jammed (bolt on edge)
Problem: Locking mechanism does not hold securely
  • The strike plate is too soft or poorly attached.
  • Goal/wing has too much play
  • Closing point incorrectly positioned (lever effect due to wind)
Problem: Opens at the wrong moment
  • Switching logic incorrect (relay inverted / incorrect NO/NC contact)
  • Unlock time incorrectly set
  • Interference / poor wiring
If you want it resolved quickly: Write us a short message. (Gate type + drive/control + lock type + photo of installation) . Then we'll tell you in 2-3 sentences what the cleanest solution is: Contact & Customer Service

Maintenance & Care: So it doesn't die after 6 months

Every 3–6 months
  • Clean the closing point (dust, sand, ice)
  • Visual inspection of cable protection and penetrations
  • Tighten screws/stop
Once a year
  • Align the strike plate (it tends to settle slightly)
  • Functional test under load (wind pressure / counter-pressure)
  • If it's stuck: don't wait, adjust it.

Practical examples from everyday life

Case #1: “The gate was closed… until the wind came”

A classic problem with large wings: The drive pulls in, but without a proper locking mechanism, wind pushes the wing open. The solution was not “more force”, but a cleaner locking point + electric lock.

Case #2: “Door opener only works sometimes”

The cause was not the opener, but voltage drop over a long cable. After switching to a clean power supply (and with the correct cross-section) it ran stably.

Case #3: “Combined lock installed – but no concept”

Code is great. But without clear rules for emergency opening/fail-safe/fail-secure, it quickly becomes dangerous or unsafe. After a brief consultation, the system was complete: access + locking + emergency solution.

Useful product recommendations & accessories

Locking mechanism & fittings

You'll find the right corner here for swing gates and matching components: Swing gate operator accessories / Electric locks

Security technology

In automated systems, safety is not a “nice-to-have”. Light barriers are often the easiest and most effective way to get started.

Here's how to proceed now (without making a bad purchase):
  1. Specify gate type (swing gate/sliding gate/pedestal).
  2. Decide between fail-safe and fail-secure (safety vs. emergency opening).
  3. Check voltage/control (12/24V, AC/DC, relay contact?).
  4. Check the mechanics (attack, play, alignment).
  5. Only then should you order – or briefly inquire if you are unsure.

Bonus check: Check the casters and hinges at the same time.

If you're going to be tinkering anyway…

Many problems with the gate stem from wear and tear on the rollers, hinges, or roller brackets. If the gate "works", the closing point also suffers.

Suitable replacement parts

Smooth operation = less play = better locking. Sounds simple, but it's exactly that.

FAQ: Frequently asked questions about electric locks & door openers

1) What is the difference between an electric lock and a door opener?

A door opener releases the latch/bolt of a door. An electric lock actively locks (typical for gates).

2) What exactly does fail-safe mean?

Fail-safe means: In the event of a power failure, the door can be unlocked/opened. Good for escape routes, but less secure in case of a power outage.

3) What does fail-safe mean?

Fail-safe technology ensures the lock remains engaged during a power outage. This is good for security, but emergency unlocking must be properly regulated.

4) Can I connect any lock to any gate control unit?

Don't do it blindly. You need to check the voltage (AC/DC), power, and switching type (relay contact/supply).

5) My castle is buzzing – what is that?

Most often the cause is voltage too low, incorrect voltage (AC/DC), or mechanical stress at the closing point.

6) How do I find out if I need 12V or 24V?

It's written on the lock/type plate and often in the control unit. If you're not sure, just ask, and it'll be sorted out in 2 minutes.

7) Do I need a light barrier if I lock it?

A locking mechanism does not replace a safety device. For automatic gates, securing the gate is often mandatory and always advisable.

8) Why doesn't my swing gate close properly despite the motor?

Because engine standby power is not a locking mechanism. Wind, play, and wear can force the blades open.

9) What is more important: the lock or the strike plate?

Both. A top-quality lock on a wobbly strike plate is like a safe with a cardboard door.

10) Can I retrofit an electric lock without having to rebuild everything?

In many cases, yes. The decisive factors are the installation location, cable routing, and whether the control unit can switch cleanly.

11) How can I recognize an “incorrect” installation?

If the bolt engages at an angle, makes noises, or only works "sometimes," that's not a coincidence; that's misalignment.

12) What do I do in case of a power outage?

That depends on fail-safe/fail-secure. An emergency plan is essential (mechanical emergency opening, access, rules).

13) Do I need to hire an electrician for this?

At 230V: yes. At 12/24V it's simpler, but if you're unsure: better to have it done properly than to pay twice later.

14) Which accessories are often forgotten?

Cable protection, proper fastening, relay/switching logic, and sensible safeguarding (e.g., light barrier).

15) Can you tell me which system is suitable?

Yes. Tell us the gate type, control/drive system, and what you plan to do – then you'll get a clear recommendation.

Next step

If you now say: “Okay, I want to do it right from the start” – then you have two options:

  • You know what you need: Then go directly to the relevant categories and put together your setup.
  • If you're unsure (type/voltage/control): Then save yourself the mistake of buying the wrong product and send us a quick message. We'll help you quickly and directly.
✅ Ready for a lock that really holds?

Thanks for reading. If you'd like, we can look together at which electric lock or door opener to use. Fits your gate – including connection & useful accessories.

One sentence is enough: “Double-leaf swing gate, control XY, I want code + locking mechanism.” – we'll take care of the rest.

Get in touch now

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