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Enclosure for uncut tap cable installation enhanced with fire protection

26th May 2022
Updated 05th December 2022

Spelsberg’s Rapid-Box industrial enclosure for fast and safe tap conductor installation is now available in a fire-resistant version for use in tunnels and similar environments. WKE Rapid-Box HT removes the need for electrical installers to cut the supply cable when fitting cable taps and additional sockets. The new features mean that the enclosure provides electrical functional integrity for up to 90 minutes in the event of a fire, enabling safety systems to continue to operate. Rapid-Box is now also available in a heavy-duty version for uncut cables up to 50mm².

WKE Rapid-Box HT enables fast installation of cable taps and sockets from an existing power cable in tunnel applications including road, rail and pedestrian walkways. This design saves significant time and cost compared to installing a new supply cable, while maintaining safety throughout.

After ensuring that supply to the main cable is powered off, Rapid-Box is placed around the cable. The electrical installer only has to remove the supply cable’s outer sheath and the individual wires are then fitted into the corresponding terminals. The terminals are spring-loaded, which provides improved security and reliability against vibration compared to conventional screws, particularly for rail and road tunnel applications.

The copper or aluminium conductor wire is exposed at the contact points and Rapid-Box is then safely sealed, providing Protection Class II and meeting European approval as a switching device according to EN 61439. A PE contact can also be installed for external earth insulation.

A cable tap can then be safely installed to provide a local power supply, or a branch off with an external socket can be fitted. Rapid-Box can also be used as a connector for two cut cables. Rapid-Box is rated to an operating voltage of 400 V and offers maintenance-free service long-term.

WKE Rapid-Box HT can be used in high temperatures and is able to withstand up to 1,000°C. As applies to Spelsberg’s WKE enclosure range, WKE Rapid-Box HT ensures that fire alarm systems and emergency lighting are maintained for at least 30 minutes in the event of a fire, while pressure boosting systems for extinguishers, as well as ventilation systems, continue for at least 90 minutes. The polycarbonate enclosure provides high resistance to impact, achieving the IK08 rating, and can withstand high power water jets as the box is tested to IP66/67.

The new fire-resistant connection enclosures are available in four variants, including clamping for uncut cables with cross sections between 2.5mm² and 25mm², as well as a larger unit that can accommodate uncut cables between 16mm² to 50mm². Both sizes are available in three and four pole options.

The standard version of Rapid-Box, available in grey compared to the WKE’s orange finish that signifies fire protection, can now also accommodate heavy-duty cables up to 50mm² cross section. Designed with anti-corrosion protection, Rapid-Box enables fast and safe power supply for industrial applications including ports and dockyards, as well as construction sites.

“Rapid-Box is a fast and safe way to establish a power connection. With the new WKE version, the connection enclosures provide functional safety for tunnel applications in the UK, such as tunnels on the overground rail service, as well as underground networks, and roads. It’s also ideal for use in passenger walkways, such as those underneath large buildings, exhibition halls, and urban areas,” says Chris Lloyd, Managing Director, Spelsberg UK.

Spelsberg UK provides installation design and specification and can customise any of its enclosures as well as provide bespoke options.

Image 1: Enclosure for uncut tap cable installation enhanced with fire protection

Image 2: Enclosure for uncut tap cable installation enhanced with fire protection

Image 3: Enclosure for uncut tap cable installation enhanced with fire protection

About Spelsberg

Spelsberg is one of the largest manufacturers of electrical enclosures in the world. With over 4,000 enclosures available as standard and further customisation possible, it offers solutions for almost any application.

With the largest supply of non-metallic enclosures, ex-stock in the UK, its products are often available for delivery within 24 hours; customisation is possible on any product, including bespoke entries, engraved corporate logos or fitted terminals, within 48 hours. Products can be ordered direct from Spelsberg or from most leading supply specialists including RS, Rapid, Farnell and CPC.

Editorial Contact: Liz Patrick

Tel: +44 (0)1905 917477



Address: Progress House, Midland Road, Worcester, Worcestershire, WR5 1AQ, United Kingdom

Reader Contact:

Spelsberg: Chris Lloyd

Tel: +44 (0)1952 605849



Address: Unit 1B, Queensway Business Park, Hadley Park West, Telford, Shropshire, TF1 6AL