Protection in tough environments

TRACE HEATING is a vital technology to prevent frozen water pipes during cold months. Electric elements, controlled by a thermostat, run along pipework to ensure a desired temperature is maintained. Trace heating is essential to largescale municipal and commercial buildings, such as hotels, schools, and prisons, that could take up to 20 km or more of trace heating cable.

Protecting the thermostat

However, the technology is also vital to many other applications – and to maintain much higher temperatures. To ensure the fluidity of bitumen for the aggregate industry, trace heating maintains pipes and tanks at 160°C, or when industrial chemicals are involved, temperatures can reach into several hundred degrees centigrade.

Since 1971, Cross Electrical (Nottingham) has designed and installed trace heating systems, as well as thermal insulation, across the UK for the full variety of applications. This ranges from supplying Formula One racing teams to frost protecting grape vines at vineyards. As the company designs and manufactures its own systems, Cross Electrical also supplies trace heating systems to contractors and installers.

A crucial device within the system is the thermostat that controls trace heating temperature. Installed both indoors and outside, and often within industrial environments, thermostats have to be well protected from the elements as well as impacts. For this reason, enclosures play a vital protective role, but the housings also have to be sufficiently flexible to allow fast and easy installation of the thermostat device and its connections.

Easy installation

“With the previous types of enclosures we used, we had to drill and tap every housing in order to create cable entry and exit points. This was a very time-consuming process,” explains Paul Dable, director, Cross Electrical. “Now, with the Spelsberg enclosures, these are provided with knock outs that can be quickly removed to create the entry and exit points we need, saving us a lot of time in manufacture. We also supply thermostats and cables to contractors as kits, so this ease of use improves their installation process too.”

The Spelsberg enclosures feature a selection of knock-out points in 20mm or 25mm diameters that can be fitted with cable glands to meet the required ingress protection. This also removes pressure on manual labour, where careful drilling to maintain IP rating was previously necessary for Cross Electrical engineers when working with its former enclosure manufacturer.

The Spelsberg enclosure achieves IP66, making it suitable for indoor and outdoor use against virtually all conditions. Polycarbonate construction also means that it’s highly durable and able to withstand impact, while ensuring light weight for ease of installation.

Enclosure printing service

Cross Electrical’s XSP thermostat unit comprises a mechanical, pressure-controlled thermostat device that can manage bands of temperature ranging from 0°C-300°C for pipe sensing, or 0°C-40°C air sensing. With a power supply entering the enclosure and two heating connections exiting, temperature setting is controlled by a dial, and status lights confirm heating on/off and system health. These internals are protected by a clear enclosure cover that allows facility managers to check settings while preventing tampering. As the thermostats are typically required to maintain a set temperature, adjustment isn’t usually necessary, and Cross Electrical’s devices are designed to be maintenance free. 

Spelsberg also supplies enclosures with Cross Electrical’s branding printed directly onto the housing. “This not only presents a far more professional image, but printing onto the enclosure means that branding, contact details, and any safety information, is a lot longer lasting and less likely to be rubbed off. Previously, we applied these details with an adhesive sticker, but again, this process took extra time,” says Dable.

Chris Lloyd is managing director of Spelsberg els UK

www.spelsberg.co.uk