Why Your Control Cables Fail (And How to Fix It)
You know the feeling. You install a new system. Everything looks perfect. Then, the signals start to drop. The motors jitter. The data gets corrupted. You check the connections. You check the software. But the problem is hiding inside the cable.
Most people think a wire is just a wire. They think copper is copper. But in the world of industrial automation, this is not true. If you use the wrong cable for your instruments, you are inviting disaster.
This is where EN 50288-7 comes in.
It is not just a random code. It is the rulebook for keeping your data safe. It is the shield that protects your factory from electrical noise. If you are buying multicore cables for your control systems, you need to understand this standard.
Let’s break it down. No complex engineering words. Just the facts you need to stop signal failure.
What Is EN 50288-7?
Think of EN 50288-7 as a quality stamp. It is a European standard. But smart buyers all over the world use it. It specifically covers multicore cables used for instrumentation and control.
Why does this matter?
Because these cables carry weak signals. A motor cable carries a lot of power. It is loud and strong. An instrument cable carries data. It is quiet and sensitive.
If you put a quiet cable next to a loud cable without protection, the loud one wins. The noise jumps over. This is called Electromagnetic Interference (EMI).
EN 50288-7 tells the manufacturer exactly how to build the cable so the noise stays out. It defines the insulation, the shielding, and the testing. When you ask for a cable “according to EN 50288-7,” you are asking for a guarantee. You are saying, “I need this to work, no matter what.”
The Secret Weapon: Screening (Shielding)
The most important part of this standard is the screening. In the US, we often call it shielding. In Europe, it is screening.
Imagine you are in a noisy cafeteria. You want to talk to your friend. If you whisper, they cannot hear you. If you shout, maybe they can. But if you put a wall between you and the noise, it helps.
EN 50288-7 cables use a special wall.
- Individual Screening:This wraps every single pair of wires in foil. It stops the pairs from talking to each other. This prevents “crosstalk.”
- Overall Screening:This wraps the whole bundle of wires in a copper braid or foil. It stops outside noise (like from a big motor) from getting in.
The standard requires a specific coverage. Usually, the copper braid must cover at least 85% of the surface. If the manufacturer skimps on the copper, the holes are too big. The noise gets in.
If you buy cheap cable without this standard, you are essentially running your data naked through a storm.
Impedance: The 100 Ohm Rule
Here is a technical term that is actually simple: Impedance.
Think of it like the width of a highway. If the highway is wide, cars (data) move fast. If the highway narrows suddenly, traffic jams happen. Cars crash. Data is lost.
For instrumentation cables, the “width” must be constant. The standard sets this at 100 Ohms.
EN 50288-7 ensures that the cable is built perfectly so the impedance stays at 100 Ohms. If you mix a 100 Ohm cable with a 50 Ohm connector, you get a “mismatch.” The signal bounces back. This is called “reflection.”
When you buy to this standard, you ensure the road is smooth all the way from the sensor to the controller.
Technical Specs You Need to Know
When you talk to a supplier, you need to speak their language. But you don’t need a degree in physics. Just look for these numbers in the datasheet.
Here is a simple table of what a standard EN 50288-7 cable should look like. You can use this to check if your supplier is giving you the real deal.
| Feature | What to Look For | Why It Matters |
| Standard | EN 50288-7 | Ensures it is built for instrumentation. |
| Conductor | Stranded Copper (Class 2 or 5) | Stranded wire is flexible. Solid wire breaks. |
| Insulation | PE (Polyethylene) or XLPE | Good for high frequency. PVC is okay for low speed. |
| Screening | Aluminum/Polyester Tape + Copper Braid | Double protection is best. |
| Impedance | 100 Ohms (± 15 Ohms) | Matches your instruments. |
| Voltage | 300/500 V | Standard for control systems. |
| Color Code | Black with white numbers | Easy to trace during installation. |
| Flame Test | IEC 60332-1 | Stops fire from spreading. |
If the supplier cannot give you these details, walk away. You are risking your project.
Where Should You Use This Cable?
You might be wondering, “Do I really need this expensive stuff?”
The answer is yes, if you are in these situations:
- Near Big Motors:If your cable runs next to a Variable Frequency Drive (VFD), you need this. VFDs create massive amounts of noise.
- Long Distances:The longer the cable, the more it acts like an antenna. It catches noise. Good shielding stops this.
- Data Networks:If you are running Ethernet or fieldbus systems (like Profibus), signal quality is everything.
- Outdoor Use:If the cable is outside, make sure the jacket is UV resistant. The standard covers the inside, but you need the right jacket (like PUR or PE) for the outside.
Do not use standard house wiring for your factory machines. It is not safe, and it will not work.
How to Spot Bad Quality
Not all cables are created equal. Some factories cut corners. They make the copper layer thinner. They use cheap plastic that cracks in the cold.
Here is how you catch them:
- Check the Print:The cable should have the standard name printed on the outside every meter. It should say “EN 50288-7”.
- Bend It:Take a sample. Bend it back and forth. If the jacket cracks or the wires inside break, it is low quality.
- Check the Continuity:Use a multimeter. The resistance should be low and steady.
- Ask for the Test Report:A real manufacturer has a “Type Test Report.” This is a document from a lab proving the cable works. If they say “we are working on it,” they are lying.
Stop Signal Noise Today
Your machines are an investment. You spent good money on them. Do not ruin them with a cheap cable.
Signal noise is the silent killer of productivity. It causes downtime. It causes errors. It causes headaches.
When you specify EN 50288-7, you are buying peace of mind. You are ensuring that the signal gets from point A to point B, clean and clear.
We stock high-quality multicore instrumentation cables that meet this standard. We have the test reports. We have the stock. And we have the technical team to help you choose the right size.
Don’t guess with your wiring. Get it right the first time.
Need a quote? Contact us today. Tell us your core count and length, and we will get you a price within 24 hours. Let’s get your system running smoothly.