The CMC 500: The New Benchmark
for Personal Safety

The CMC 500 sets new standards in electrical testing technology. Its performance and precision, automatic test procedures, and versatility are all hugely impressive. However, particularly noteworthy are the advanced safety features, which establish a new industry standard for personal safety.

This focus on safety is no coincidence, since the growing electrification of all aspects of our life, at work and at home, increases the demands placed on protection mechanisms. The testing of electrical energy and protection systems, where high voltages and complex procedures collide, exposes engineers to a higher risk from electrical hazards. Safety in the field of electrical testing technology has thus become the benchmark against which every test set has to be measured.

Safety functions that set new standards

Innovative safety functions are characterized by the fact that they increase levels of personal safety yet at the same time have no adverse effect on productivity.

Status light

The CMC 500 status light indicates whether the test set outputs are de-energized or not, providing an additional level of safety. This is of particular importance when testing assets with high levels of inductance, as hazardous levels of energy can still be present.

Operating mode button

The operational mode button of the CMC 500 allows the signal outputs to be de-energized while the device is still switched on. This means work can safely be carried out on the test setup without having to power down the device completely. Reconnecting of the test set and the testing software is no longer necessary.

Interlock key

Removing the INTERLOCK key from the CMC 500 ensures that the device cannot be activated unintentionally or by any unauthorized personnel. This means that safety cannot be compromised, even when the device is out of sight. After reinserting the interlock key, the device is immediately ready for operation again.

Safety Link

The Safety Link enables the CMC 500 to be enhanced with emergency switching off buttons and a safety light – without the need for an external power supply. This provides excellent visibility, ease of access, and a test setup that conforms to EN 50191. The safety light integrated into the emergency switching off button indicates the status of the devices connected to the Safety Link.

Note: The enhanced emergency switching off buttons will be available shortly.

Additional information concerning "personal safety"

What are the typical dangers encountered during testing?

Dangers posed by the environment

Visibility & access: Test locations are often not directly visible. This increases the risk that someone may enter the danger zone without being noticed, or that emergency situations are not detected early enough.
System errors: When a complete system is being tested, defective components may produce unpredictable reactions – for example, a malfunctioning protection relay may output incorrect signals.
External influences: Frequently, a number of people may be working in the same work area. In such cases, poor communications or accidental activation can be a source of danger.

Dangers posed by the test set or the testing procedure

Electrical shock: Test sets generate high voltages. Before starting work, the test set (or its outputs) must be disconnected from the power system. Safety plugs should also be used and connected in the correct sequence.
Wiring errors: Using a large number of cables makes it difficult to keep an overview. Errors can result in damage or personal injuries, so careful and accurate working is essential.
Incorrect grounding: A broken protective ground wire represents a hazard for people and devices. An additional protective ground is mandatory.
Procedural errors: Time pressures can tempt people to take short cuts, e.g., carrying out rewiring without switching off the device first.
Measuring errors: Calibration can become inaccurate as a result of aging or environmental factors. Regular checks must be carried out.

What does personal safety involve in the field?

The safety measures that have been adopted in the field are often derived from standards and subsequently enhanced by the imposition of operational requirements. Typical measures, for example, might include: work instructions, safety training courses, personal safety equipment (PSE), risk assessments, safety indexes.

The "5 safety rules", which are now internationally accepted when working on electrical installations, are particularly important:

1. Insulate
All system components must be completely disconnected from the power system – including possible return voltages.

2. Secure to prevent reconnecting
Secure switchgear, e.g., with interlocks or warning signs, to prevent unintentional reconnection.

3. Verify that the installation is dead
Using suitable measuring equipment, test each conductor to ensure it is not live. A voltage may be caused by a feedback loop or another test set.

4. Carry out grounding and short-circuiting
First connect to the grounding arrangement and then to the system component. All connections must be securely connected and short-circuit proof.

5. Provide protection from adjacent energized parts
If adjacent live parts cannot be switched off, cover or shield them.

Which standards are relevant for personal safety?

Safety standards are at the heart of personal safety in the development of tests sets. IEC 61010-1, ISO 13849-1 (incl. IEC 61508-3), and EN 50191 are particularly relevant.

IEC 61010-1: Safety requirements for electrical equipment for measurement, control, and laboratory use
IEC 61010-1 specifies the general safety requirements for electrical equipment for measurement, control, and laboratory use. Its objective is to minimize the risk for users and the environment. Among other points, it stipulates the protective measures that will eliminate electrical, mechanical, and thermal hazards, and prevent the spread of a fire that might be caused by a faulty device.

ISO 13849-1: Functional safety
This standard describes how the control components (including software) that are important in terms of safety have to be configured. The objective is to minimize the chances of a dangerous error occurring. The standard has been extended by the inclusion of IEC 61508-3 for the software. It applies regardless of the type of technology, in other words it applies to electrical, mechanical, and hydraulic systems.

EN 50191: Erection and operation of electrical test equipment
This European standard governs the installation and operation of electrical test installations. Among other things, it includes requirements for protective measures, personnel, testing procedures as well as, for example, the signaling using lamps (red/green) to indicate operating statuses.

The CMC 500 redefines the meaning of safety in the field of electrical testing technology. Featuring safety functions conforming to international standards, it offers the highest levels of reliable and tested protection.

Sophisticated features, such as status lights, the operational mode button, the interlock key, and Safety Link, ensure that personal safety is not just guaranteed, but also integrated intelligently into the testing process – without compromising efficiency or user-friendliness.

Discover all the advantages of the CMC 500