As they are prone to impaired cable insulation from screws, nails, and rodent damage, arc detection technology is now being used to protect 19 historic windmills in the village of Kinderdijk in the Netherlands. This not only safeguards the world-famous wooden structures from fire but improves safety for both residents and tourists.
Limited space, coupled with outdated electrical systems pose a very real threat to all old buildings. Indeed, there are over two million fires in Europe every year, and more than one third of these are due to faults in the electrical installation which largely occur following dangerous arc faults. Wooden structures are particularly vulnerable, as a single spark has the potential to ignite a fire.
Preserving a piece of Dutch history
Built around 1740 in the wetlands near the oldest city in the Netherlands, Dordrecht, the mills originally formed part of an entire water management system. They were key to flood control, and the preservation of the low-lying land, draining water from the polders – the name given to lowlands reclaimed from the sea or a river and protected by dykes – into the Lek River. They also helped to keep the polders of the Alblasserwaard dry.
For their historical and vast symbolic value as an example of Dutch ingenuity in land conservation, the mills were declared a UNESCO World Heritage Site in 1997. To ensure their preservation, the Kinderdijk World Heritage Foundation (SWEK) was established at the beginning of this century.
One single spark can cause a fire
Also covered with reeds, the 200-year-old Dutch watermills require careful preservation. Two devastating fires in 1981 and in 1997 burnt two of the mills to the ground.
A recent independent site inspection revealed the electric systems needed to be upgraded to ensure the best possible level of fire safety, as Jeroen van Gent of Netherlands-based, Van Gent Elektroservice, explains.
“We were commissioned to replace the distribution boxes of the mills,” he says. “This also included protecting the installation against overloads, short circuits, and earth faults, as well installing arc fault detection devices (AFDDs) to protect against arc faults.”
With many of the mills also used as private residences, upgrade works had to be carried out without losing power supply for long periods. Components or subsystems had to be compact, suitable for retrofitting onto pre-existing electrical systems and quick to install to minimize power outages.
“As fire is a major risk, we chose a distribution box from ABB,” says van Gent. “This is because ABB delivers a qualitative and versatile total package of security components, including arc protection, which is so important for this project as it offers the residents and mills protection against fire. We therefore advised the foundation to provide the mills with new junction boxes with arc detection."
ABB AFDDs: modern solutions for older buildings
ABB's DS-ARC1 Arc Fault Detection Devices (AFDDs) are equipped with an integrated Residual current Circuit Breaker with Overcurrent protection (RCBO) which adds protection against earth fault currents and over currents to the arc fault protection. As Jacco Brasser, sales engineer, Smart Buildings at ABB explains, it also features a continuous self-test to ensure safety and continuity of the installation.
"Upon detection of an arc, the AFDD device automatically shuts down the installation and prevents worse incidents,” Brasser states. “What makes an electric arc so dangerous is the fact that it can occur anywhere in the installation without being noticed. Especially in older buildings, the risk is high due to damaged or loose cables – and in old wooden mills, where a mouse sometimes gnaws at the wiring, the risk and the possible consequences are even greater.”
Each year, more than two million fires break out across Europe and more than one third of these are caused by faults in the electrical installation, which usually occur because of dangerous arc faults.
“Although arc detection is not compulsory in the Netherlands, but recommended in the NEN 1010 guidelines, it is still regularly applied,” says Brasser. “Arc detection protects both old and new buildings against fire. For monumental buildings we always recommend arc detection.”
A safer future for Dutch tourism
Jan-Dirk Verheij of the SWEK foundation paid tribute to van Gent's approach to the Kinderdijk project, including the decision to provide the mills with junction boxes with ABB arc detection.
“To maintain a mill, it must turn regularly,” said Verheij. “This is not only beneficial, but also a great attraction for the hundreds of thousands of tourists, who visit Kinderdijk every year. Now that the mills have additional protection against fire, we can welcome them with confidence."