Spiral cables & junction boxes for gates: selection, installation & troubleshooting
When a gate "frequently malfunctions", it is surprisingly often not magic – but a cable that has been pinched, kinked or simply routed incorrectly.
And yes: These small mistakes cost time, nerves, and a lot of money in the business.
This guide provides a clear procedure: What length of coiled cable is suitable? Where should the junction box be placed?
How do you install strain relief correctly? And above all: How do you quickly find faults without blindly replacing parts?
We don't sugarcoat this: You'll get checklists, typical error patterns, and a clear selection logic – so you can order correctly the first time.
and don't swear three times.
Table of contents
- Why coiled cables & junction boxes cause so much stress
- Typical symptoms: This is how a cable problem manifests itself.
- Technical basics: What a coiled cable must be able to do
- Technical basics: What makes a junction box right
- Locations at the gate: Where is what located – and why
- Quick choice in 3 questions
- Length & path of movement: How to measure without guesswork
- Wires, cross-section, signals: This is what you need to know
- IP protection, seal, cable gland
- Complete set vs. individual parts: When is which worth it?
- Planning: Cable routing, chafing points, strain relief
- Planning: Mounting point on the gate leaf (the "power zone")
- Tools & Materials List
- Assembly: Secure the spiral cable neatly (step by step)
- Installation: Install the junction box, seal it, done.
- Wiring: terminals, labeling, continuity test
- Commissioning: Tests you should really do
- Troubleshooting table: Symptoms → Cause → Solution
- Maintenance & Checks: How to make your setup last longer
- Meaningful upgrades: Integrating sensors and security seamlessly
- Quickly find relevant products & categories
- FAQ
Why coiled cables & junction boxes cause so much stress
Gates move – every day. If the cable rubs, kinks, or hangs without strain relief, damage is only a matter of time.
Sometimes it works, sometimes it doesn't. This is often due to loose connections, broken wires, or moisture in the junction box. And that costs you hours.
A cable can be laid "any old way" in a flash. But that backfires in the workplace: malfunctions, downtime, emergency service. Only Murphy's Law is laughing.
Typical symptoms: This is how a cable problem manifests itself.
- The safety circuit is briefly opened (loose contact).
- The connection briefly breaks down during movement.
- The plug/terminal is not seated properly.
- The cable kinks in a certain position.
- Spiral pull too tight/too loose.
- The chafing point hits exactly there.
- IP protection not suitable for the environment.
- Cable gland is leaking or incorrectly installed.
- Damaged seal – a classic.
Depending on the system, work on the control system / in the control cabinet should be carried out by a qualified electrician. If you're unsure, leave it alone and get some help. A goal isn't a toaster.
Technical basics: What a coiled cable must be able to do
The spiral absorbs the gate movement without the cable constantly bending sharply. The important thing is: enough reserve, but not so much that it rubs against something.
Cables rarely die "just like that". It's usually due to kinks, unexposed tension, or friction against metal edges. That's precisely where proper assembly comes in.
The crucial factors are the number of wires, their length, and the type of connection. If you have sensors (e.g., a closing edge sensor) attached, the electrical connection has to be compatible – period.
Technical basics: What makes a junction box right
A good junction box protects the connection from dust/moisture and makes maintenance easier: open, check, replace – without cable clutter.
The seal, cable gland and correct fit determine whether it corrodes in 3 months – or still runs smoothly in 3 years.
If the cable is moving inside the junction box, the terminals will also move. The result: an intermittent connection. Strain relief is essential, not optional.
Locations at the gate: Where is what located – and why
- Spiral cable hangs/leads with
- Keep a safe distance from scissors/hinges.
- No chafing on rails/edges
- Connection to junction box
- Clean execution towards control
- Choose IP protection according to environment
- Refer to the terminal diagram
- Label the cables
- Test continuity and function
Quick choice in 3 questions
- Just a simple contact?
- Multiple sensors?
- Safety chain / closing edge?
- Determine stroke/opening height
- Determine mounting point
- Allow extra space for a clean bending radius.
- Dry inside vs. wet/dusty outside
- Washing/Moisture? → Take IP protection seriously
- Mechanical stress → Protective guide
Category “Cables & Connection Boxes” in the shop: View spiral cables & junction boxes
Length & path of movement: How to measure without guesswork
- Close the gate completely → Remember the starting point.
- Open gate completely → Note endpoint.
- Measure the distance between the mounting point on the gate leaf and the fixed transfer point (box/frame).
- Plan for a reserve: nothing should be under tension at the final stop.
The coiled cable is chosen "on the edge". Result: At its maximum setting, it's as taut as a guitar string – and will later break right there.
Too long – and the spiral will rub against something, wrap itself up awkwardly, or get caught by moving parts. Not ideal either.
Wires, cross-section, signals: This is what you need to know
You don't need to be a master electrician – but you should know whether you are only switching one contact or whether multiple signals need to be transmitted cleanly. And: When it comes to security systems, "connected somehow" is not an option.
- Simple contact: e.g. door contact / status contact
- Multiple sensors: multiple wires required.
- Safety circuit: must be stable, no loose connections, securely clamped.
If you are unsure: take a photo of the nameplate, the connection and the current cable routing. Then you'll avoid making the wrong purchase and we can provide meaningful help directly.
Many "electrical" problems ultimately stem from mechanical issues: a misaligned gate → cable rubs. Check the rollers: ball-bearing rollers
IP protection, seal, cable gland
When it's dry, the primary concern is protection from dust and mechanical stress. Nevertheless: close the junction box tightly and route the cables neatly.
As soon as water, condensation, or a lot of dust is involved, the IP rating determines whether it "works" or "faults." The seal and screw connection must be compatible.
Whether indoors or outdoors: if the cable pulls on the clamp, you'll eventually touch it again – just at the wrong moment.
For neat cable routing, you often need small parts (clamps, screws, holders). View mounting hardware
Complete set vs. individual parts: When is which worth it?
| variant | Advantage | When is it useful? | Typical mistake |
|---|---|---|---|
| Complete set | Everything fits together, less risk | If you want to finish quickly and safely | The set is assembled "somehow" without any cable routing planning. |
| Individual parts | Maximum flexibility | If you have special cases (mounting point, length, special can) | The parts do not fit together properly electrically/mechanically. |
| Retrofit only socket | Fast service | If the socket is leaking/corroded, but the cable is okay | The fault lies in the cable – it's being overlooked |
Planning: Cable routing, chafing points, strain relief
- No sharp edges
- No friction on rails/hinges
- Keep movement zones clear
- Install strain relief in front of the can.
- Leave room for movement
- No pulling on clamps/plugs
- Protective hose/duct, if necessary
- Set fixed points (but don't strangle them)
- Labeling will save time later
If roller holders are worn out, the gate runs "strangely" – and cable paths change. Here you can find suitable parts: Roll holders & hinges
Planning: Mounting point on the gate leaf (the "power zone")
- protected from direct friction
- Logically sound movement (spiral works cleanly)
- no contact with scissors/hinges
- close to sharp-edged sheet metal
- The spiral is "pulled" during the run.
- Cable is lying in dirt/water
It's better to plan for 10 minutes longer than to make a "short" trip every week later. Cable problems are the most annoying kind of problem: small – but fatal to the process.
Tools & Materials List
- Screwdriver / Bit Set
- Side cutters + wire strippers
- Multimeter (continuity)
- Drill bit / Fastener depending on the substrate
- Spiral cable suitable for the application
- Junction box + seal + screw connection
- Clamps / Cable ties / Holders
- Labeling (tags) – seriously, do it!
Assembly: Secure the coiled cable neatly (step by step) 🔧
- Power off / Secure the system (yes, really).
- Define cable routing : Movement zones are clear, no chafing points.
- Set a fixed point on the gate leaf : so that the spiral "works" cleanly.
- Install strain relief before the cable enters the socket.
- Check reserve : Open/close the gate completely (manually/secured) and check if any voltage is generated.
If you notice at step 5 that it's getting tight: don't discuss it – correct it. That's the difference between "it's working" and "it'll be back next week".
Installation: Install the junction box, seal it, done.
- fixed, quiet area (frame/near control)
- so that service is possible (lid accessible)
- not directly in the splash zone
- Insert the seal cleanly
- Tighten the cable gland correctly.
- no cables that are "under tension"
Can closed = sealed. Can "half" closed = moisture later. And then it gets nasty at the terminals.
Wiring: terminals, labeling, continuity test
Each vein is clearly assigned a specific location. It's not a case of "it'll be fine". Later, you'll want to know what's what in 2 minutes.
- Check each line individually.
- Simulate movement (goal positions)
- If it disappears sporadically → cable break/loose connection very likely
Send us photos and information, and we'll tell you what you need and where the problem likely lies: Contact & technical advice
Commissioning: Tests you should really do
| test | How | How you can recognize it |
|---|---|---|
| Visual inspection | Cable routing, chafing points, lid/seal | Nothing is rubbing, nothing is under tension |
| Movement test | Gate fully open/closed while observing the cable | The spiral works smoothly, no jamming. |
| Contact/Sensor Test | Trigger sensor / Check safety circuit | The control system reacts reproducibly |
| Sporadic test | Drive several cycles | No problems after 10–20 trips |
- If you're setting up from scratch: first the cable run, then the socket, then the wiring.
- If you are looking for a fault: Pass + movement tests in different goal positions.
- If it remains sporadic: suspect the cable/plug first – not the controller.
Troubleshooting table: Symptoms → Cause → Solution
| symptom | Probable cause | What you do |
|---|---|---|
| Fault only occurs when opening | The spiral becomes too tight in the upper area. | Correct mounting point/reserve, check strain relief |
| Fault only occurs when closing | The cable gets kinked or rubbed at the bottom. | Change cable routing, install protective guide |
| Errors "come and go" | Loose connection / broken wire | Measure continuity while moving, readjust clamps, replace cables if necessary. |
| Corrosion in the can | Leakage / incorrect IP protection | Check the seal/screw connection, replace the can, and properly seal the lines. |
| Sensor not responding | Wires swapped / wrong connection | Labeling + terminal diagram, check step by step |
Maintenance & Checks: How to make your setup last longer
- Visual inspection of cable route (chafing marks?)
- Check the outside of the can (cracks, loose screws)
- Spiral: does it work smoothly, without tension?
- Check clamps (tight, dry)
- Check strain relief
- Drive multiple cycles and observe
Check the mechanics – otherwise it will ruin even the most beautiful wiring. You can find casters and roller holders here: casters / Roll holders & hinges
Meaningful upgrades: Integrating sensors and security seamlessly
Protect the roadway – and cleanly resolve many “gate stops/reverses” stories. View light barriers
If you need a clean closing edge protection, the connection needs to be done properly. Optosensors & closing edge protection
If a wicket door is involved: reliable contact must be established within the security circuit. wicket door contacts
We'll also help you make a sensible choice (no buzzwords). Just tell us briefly what you have and add a few photos: Open contact page
Quickly find relevant products & categories
FAQ
What length of coiled cable do I need?
The length depends on the range of motion and the mounting point. Important: Nothing should be under tension at the end stop, otherwise the cable will break.
Why does my mistake only occur "sometimes"?
This is typical of a broken wire/loose connection. As soon as the gate reaches a certain position, the signal briefly drops out.
Can moisture in the junction box cause malfunctions?
Yes. Corrosion on terminals quickly turns a "leaking" situation into an "intermittent" one. Seals and cable glands are key here.
Are cable ties sufficient as strain relief?
Sometimes it can be used as a "last resort" – but the proper solution is: a correct clamp/strain relief so that no force is exerted on the clamps/plugs.
What is the most common cause of cable breakage at the gate?
Incorrect cable routing (chafing/kinking) and length chosen too short without reserve.
Complete set or individual parts – which is better?
Complete set = less risk. Individual pieces = more flexibility. If you're not 100% sure, a complete set is often the faster way to win.
Can a misaligned gate cause cable problems?
Absolutely. When the gate "works," the cable routing moves with it – and then it rubs/pinches. It's worth checking the mechanics.
How do I test if the cable is broken?
Measure the passage – at several goal positions. If the passage is only absent at certain positions: goal.
What do I do if I don't have a terminal diagram?
Take photos of the control unit/connection + gate/components and clarify with support – then you'll save yourself trial and error.
Can I do that myself?
Mechanical assembly and cable routing are often possible – work on the control system / in the control cabinet should be clarified carefully depending on the system.
How quickly will I receive help with the selection?
If you provide photos and information (gate type, application, problem), the consultation will be significantly faster.
If you want, save yourself the "guessing marathon": Just send us a few photos (cable routing, junction box, control unit/nameplate) and tell us,
What exactly happens. We'll tell you directly what makes sense – and what you can skip.
And yes: The goal is for your goal to simply flow. Without drama.
