Incorrect electrical connections are one of the most common causes of fires in electrical systems. We explain the HOW and WHY and outline how special professional torque tools for the electrical trade help protect you while also boosting efficiency....
In the electrical trade, workers have to be able to rely on their tools. They need to know that their tools are safe, i.e. they will not be exposed to hazardous voltages, but also that they have legal certainty when it comes to proof of compliance with manufacturer specifications. From switch cabinets to wiring – each screw connection must be made correctly and safely. Although correct torque plays a decisive role in assembly, this is often underestimated.
What happens if screws are undertightened or overtightened?
Damaged components due to overtightening or loose connections can lead to higher contact resistance. This generates heat which, under certain conditions, poses a fire risk (*1)...
The most common errors found in electrical connections during fire investigations include:
- Loose electrical connections because the clamping screws have not been tightened to the required torque.
- Damage to the conductor/clamping body because excessive torque has been applied to the clamping screws
- Electrical conductors not inserted in the clamping body correctly, the conductor insulation is also clamped or the contact surface is insufficient.
- Unsuitable tools used for crimp connections and consequently the conductor and/or connecting element are damaged or don’t have enough contact pressure…
The tricky part and the best means of prevention
The best way to avoid a fire risk is to establish electrical connections correctly. Expert knowledge, experience, skill and diligence are vital. Otherwise, faulty electrical connections with excessive contact resistances can only be detected by regular, extensive testing and measurements. However, a problem could still occur between tests - so what happens then? In other words, 100% safety cannot be guaranteed simply by regular testing. Prevention is therefore better than cure...
Therefore, always observe the following points to be on the safe side:
- Use high-quality connection materials,
- Comply with the manufacturer's specifications regarding the correct torque and
- Be sure to use professional tools.
How do I know I am using a professional torque tool?
- When working on live systems or parts, one basic requirement in the electrical sector is that the equipment is reliable and provides 100% protection against electric shock. The chosen tool should be insulated and VDE-tested.
- It is also important for the tools to have an ergonomic design to reduce fatigue and conserve as much energy as possible when working for longer periods.
- In order to be able to work efficiently and quickly, a torque tool should be flexible and versatile. Different applications require different torque settings and/or screw profiles. Tools that can adapt exactly to the situation quickly and easily and cover the relevant torque ranges in the electrical trade are therefore ideal.
One set, many possibilities
The TorqueVario®-S electric torque screwdriver set by the hand tool manufacturer Wiha Werkzeuge is an example of a professional solution that rises to the unique challenges of the electrical trade.
- A variably adjustable torque range of 0.8-5.0 Nm enables users to complete a very wide range of fastening tasks with varying torque requirements quickly and flexibly.
- The ergonomically designed torque screwdriver handle ensures work can be carried out comfortably and in a way that is conducive to health.
- 15 interchangeable slimBits equip professionals for different screw profiles, irrespective of the component requirements.
- All components are arranged practically in a high-quality, hard-wearing bag, where they are easy to identify.
- Thanks to the slimBits,even low-lying screw elements can be easily reached.
- The tool emits a clear audible and perceptible signal when the required torque has been reached.
- The process-safe torque mechanics ensure that the component is tightened to exactly the right torque according to the manufacturer's specifications. This prevents material damage and follow-up work.
- Both the torque screwdriver and the slimBits undergo routine testing at 10,000 V AC as per the international IEC 60900 standard, to provide protection against live components up to 1,000 V AC in the worst-case scenario.
The perfect combination for peace of mind: torque and documentation
For professionals in the electrical trade, it is common knowledge that the documentation of work on electrical systems is crucial, in particular to demonstrate due diligence and to protect oneself in the event of damage. Complete, transparent documentation helps demonstrate the proper condition of the system and compliance with technical standards.(*³)
Tip 1: Document the use of torque tools by noting that the specified torque was applied. This can be important for safety-critical connections in particular, as incorrectly tightened screws (overtightened or undertightened) can cause problems such as charring or electrical fires(*4). A note of this kind can be included in the log to document that the correct tool was used and the connection was tightened with the correct torque.
Tip 2: Use innovative, digital project documentation tools. Using these tools not only makes documentation easy, but also more efficient and smarter compared to more traditional methods. The free Wiha ProDo easy app is a solution designed specially for the electrical trade to simplify documentation tasks for professionals in their day-to-day work – have a look here…
Fire prevention pays off
The answer to the question as to whether it is worth buying professional torque solutions is clear: Compared to potential flat fires or extensive fires at facilities, minor charring damage is still considered the lesser evil. The question of sufficient public liability insurance to cover any costs resulting from property damage or business interruptions doesn’t even arise if the installation is carried out correctly using the right torque
The bottom line: Better safe than sorry
Whether in daily use or for special projects – torque tools have long since become indispensable in the electrical trade. They ensure that the screw connection is correct every time and keep dangerous situations at bay. When opting for a tool, quality, reliability, safety and flexibility are key. After all, professional results can only ultimately be achieved by adopting the right approach, whether in terms of equipment, choosing the correct torque, or your standards for your own work quality.
More information on the product
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Sources:
(*1) from: ‘Die vorschriftsmäßige Elektroinstallation’, 19., revised edition, Hösl, Ayx, Busch
(*²): At the referenced points, we refer to the expert articles of Volker Pankrath at the German Institute for loss prevention and damage research of public insurers (Institut für Schadenverhütung und Schadenforschung der öffentlichen Versicherer e.V.). His complete article “Eine „heimtückische“ Brandgefahr: Die fehlerhafte elektrische Verbindung” which discusses the fire hazards in relation to faulty electrical connections, was published in schadenprisma.de / 3/2015 among others. https://www.schadenprisma.de/pdf/sp_2015_3_1.pdf
(*³): Can be read in the German article “Rechtssichere Dokumentation elektrischer Anlagen - Elektropraktiker”
(*4): Case study: Brand durch fehlerhafte elektrische Kontakte - Elektropraktiker).