CE certificate for LED signal lights is important already in product development

When a small company develops a new machine, an automatic device, a robotic cell or its own industrial product, a great deal of attention is paid to mechanics, electronics, programming and functionality. LED signal light is often seen as a small component of the entire project. In fact, he has a very important task.

He needs to tell the operator what's going on with the device within seconds. Does the machine work normally? Is he waiting for the material? Does he need help from the operator? Is there a mistake? Do you need an immediate reaction?

This is why it is not only the price of LED signal lights that matters when choosing. For a company developing a product for sale, the issue is also important CE conformity of LED signalling lights and documentation obtained with the product.

Term CE certificate is often used in trade and component procurement, but it is important to understand the difference. CE marking is not, as a rule, a classic quality certificate simply issued by a European institution. The CE marking shall indicate that the product complies with the requirements of European legislation applicable to a specific product.

LED signal lights for industry allow fast detection of the state of the machine

Good industrial signalling reduces speculation. The operator does not need to walk to the machine screen, open a diagnostic program or search for faults on the control panel. The signal tower may be visible from the other side of the production area.

LED signal lights are therefore mainly used for:

• demonstration of normal machine operation,
• alerting the irregularity or deviation of the process,
• malfunction display on the machine,
• warning of material shortages,
• an operator intervention requirement,
• demonstration of the completed production cycle,
• signalling production congestion,
• demonstration of readiness of the device,
• signalling in robotic and automated systems,
• visual support to Andon systems and other production monitoring systems.

Especially useful are multi-colour LED signal tower lights, as a single device can display several different conditions.

The colours of industrial signal lights have their meaning

In industrial signaling colors is not good to choose just because the designer likes them. IEC 60073 sets out the general principles of colour coding of indicators.

• Red as a general rule, warns of danger, state of emergency or error.
• Yellow points to an abnormal condition, warning or need for increased attention.
• Celery as a rule, it represents a safe or normal condition.
• Blue may be used for a situation where a specific action by an operator is required.
• White is not of general safety concern and is frequently used for additional information.

This does not mean that it is only by choosing the correct colour that we can save the entire security signaling machine. The meaning of the individual signalling must be clearly defined in the design of the machine, the software logic, the instructions and, if necessary, on the machine itself.

For a small development company, such an approach has another great advantage. When the same machine is upgraded or assembled in six months, the logic of signalling is still understandable.

CE conformity of LED signalling lamps is not only a label on the housing

On-line purchases of industrial components can quickly find a CE marked LED signal light. However, the label on the product photo alone is not enough if we intend to use the component in the product we will later sell.

It is much more useful for a development company if the supplier can provide:

• clear manufacturer code,
• the exact type and model of the signal light,
• EU declaration of conformity,
• an indication of the rules on the basis of which conformity has been assessed,
• details of the standards used,
• technical data on power supply and consumption,
• the permissible temperature range,
• iP protection level, where indicated,
• data on EMC compliance, where relevant,
• roHS compliance data,
• instructions for proper installation and use.

The documentation must be related to a specific product. A PDF document bearing the CE inscription, where it is not possible to determine which model it refers to, is much less useful for the technical documentation of your new machine.

EMC and RoHS are very important for LED signal lights

The LED signal light is often no longer just LED diode and resistance. The housing may contain electronic power supplies, controllers, flashing electronics, an audio module or a communication interface.

Therefore, in the case of electronic signalling devices, it is necessary to check in particular the rules applicable to the concrete implementation of the product.

• EMC refers to electromagnetic compatibility of electrical and electronic equipment.
• RoHS restrict the use of certain hazardous substances in electrical and electronic equipment.
• LVD is used for electrical equipment within specified voltage ranges.
• RED may become relevant if the signalling device contains a radio communication module.
• ATEX is relevant for equipment intended for use in potentially explosive atmospheres.

This is also why it is not possible for all industrial LED signal lights to simply write the same list of directives. It is always necessary to look at the actual construction, power supply, purpose and environment of the use of a specific product.

24 V LED signal light and LVD directive

Many industrial signal towers use 24 V DC power supply. This is very practical because such signal lights can be directly integrated into normal industrial control systems, PLC outputs or corresponding relay or transistor outputs.

Here comes an interesting detail that many people overlook when developing their own devices.

Directive LVD 2014/35/EU refers to electrical equipment designed for voltages between 50 and 1000 V AC or between 75 and 1500 V DC. A normal signal light operating only on 24 V DC, so it does not automatically fall into the LVD area because of its supply voltage.

This does not mean that there are no requirements for 24 V LED signal lights. Other relevant rules and the full use of the product still need to be assessed.

CE component marking does not constitute CE conformity of the whole machine

This is one of the most important information for smaller companies developing their own machines.

We can buy PLC with CE marking, CE marked power supply, CE marked motor controller, CE marking sensors and CE marking LED signal tower. When all these components are assembled into a new machine, this does not automatically create a CE compliant machine.

The final product is a new whole.

It shall assess the requirements applicable to the end-of-life appliance, draw up the relevant technical documentation, assess the risks and verify the interaction of the components.

This is why quality documented components for smaller developers are so valuable. They do not solve the whole process, but they can simplify it considerably.

CE documentation in developing a new machine saves problems before selling

The worst time to check the individual component documentation is when the machine is already finished and the customer is waiting for delivery.

That's when we find out the signal light supplier no longer exists. Or we just have a photo of an online ad. The declaration of conformity shall refer to another Cataloguing Number. EMC documentation missing. There is no manufacturer on the product. The specified IP class has no traceable documentation.

It is much smarter to collect documentation as we go along.

Any major electrical component can be stored:

1. invoice or proof of supplier,
2. datasheet product,
3. instructions,
4. EU declaration of conformity,
5. any test reports,
6. a photograph of the type marking,
7. the exact catalogue number of the component used.

In the first machine, such work may seem unnecessary. At the tenth machine we have practically our own library of verified components.

Industrial LED signalling simplifies diagnostics and service

A good signal light is not only useful during production. It also helps perfectly with machine diagnostics.

Imagine a smaller automatic machine using three basic conditions:

• green means normal automatic operation,
• yellow means waiting for material or operator intervention,
• red means failure or system shutdown.

The repairman can see the basic state of the system when he reaches the device. If the controller supports multicolor RGB signalling, we can expand the system even further.

For example:

• slow pulse for waiting,
• rapid pulse for emergency,
• an audible fault signal,
• a different colour for manual mode,
• special signalling for service mode,
• end of series signal,
• warning of almost empty material.

A small investment in signalling can thus greatly improve the user experience of the entire machine.

Customer experience in developing your own automatic machine

The following example illustrates the typical experience of a small company in developing its own automated device.

On the first prototype, we chose the signal light on practically the last day. All we cared about was that it had red, yellow and green LEDs. When we started preparing the machine documentation, we found that we hardly have any useful information for the purchased light. With the next device, we chose from the beginning a model with clear documentation and an EU declaration of conformity. There was a huge difference in documentation preparation. An even greater advantage has been shown by the user, since he can now see from the other side of production whether the machine is working, waiting or needing its help.

This is a small change that can very professionalize the product.

LED signal light must also correspond to the actual environment of use

Certificates and documentation are important, but they do not in themselves state whether a given signal light is suitable for your project.

Before selecting, it makes sense to check:

• supply voltage,
• use of each channel,
• steering mode,
• compatibility with PLC outputs,
• visibility from different angles,
• luminance of the LED elements,
• temperature range,
• vibration resistance,
• IP dust and water protection,
• method of attachment,
• cable length or method of connection,
• sound alarm capability,
• the possibility of changing or adding modules.

The signal light for the laboratory table machine has completely different requirements than a signal tower installed over an industrial machine in a dusty or damp manufacturing environment.

CE certificate for LED signal lights is an important part of a professional product

For large companies there are departments that deal only with standards, type approvals and documentation. A small entrepreneur often does all this alone. In the morning the PLC programs, in the afternoon the carrier is made on the CNC machine, in the evening it orders sensors and the next day it is already a prototype.

This is why it is worth using verified and well documented components.

In Svet Črnil when developing industrial solutions, we are well aware of how quickly a small component can become a major problem if it is not later able to obtain appropriate technical data.

The LED signal light is cheap compared to the entire machine, but represents direct communication between the machine and man. If properly selected, understandablely programmed and equipped with appropriate documentation, it becomes a small but very important part of a professionally manufactured industrial device.

Do you also want to equip your new machine or innovative product with a clear, professional and properly documented LED signalling without stopping the project just before the sale?