Text Dr. Jörg Lantzsch, Hans-Robert Koch ––– Photography
True character often only becomes apparent when the going gets tough, and enclosures are no exception. If they are able to handle extreme situations with ease, everyday operations become child’s play. Take the example of tunnel applications, where enclosures on the tunnel wall may house safety lighting systems and the power supply for emergency teams. This proves how resilient they really are, because a high-speed train generates a huge pressure wave as it passes through a tunnel – an effect that is greater still if two trains pass each other in the tunnel. Enclosures need to withstand the extreme pressure fluctuations and also high wind speeds.
TUNNEL-TESTED
Successful testing at the German Aerospace Center (DLR) has confirmed the new AX plastic enclosures from Rittal meet these very requirements. Three sizes of the newly developed enclosure were put through their paces based on a Deutsche Bahn directive (Ril 853.2001 A01). In the DLR’s wind tunnel and pressure chamber, they demonstrated their extreme resilience and their suitability for both tunnel applications and rail projects.
ICE, RAIN AND SUN
These new arrivals have even more to offer, though. They are equally impressive out in the open – in the water and wastewater industry, for example – where they are continuously exposed to weathering caused by ice, rain and sun. Rittal is still using fibre-glass-reinforced polyester for its plastic enclosures, but modifying the composition of this material has made it seven times more resistant to UV radiation. What’s more, the enclosures comply with the UL F1 outdoor rating (UL 746C). A further advantage is their ability to keep out both dust and water. To comply with protection category IP 66/NEMA 4X (IP 56/ NEMA 12 if a viewing window is integrated), Rittal has equipped the door of its new enclosures with an all-round seal. To offer protection against dust and water, a rain protection strip is located at the top and bottom edges of the door.
The plastic enclosures also boast excellent fire protection. The material complies with class V-0 of the UL 94 standard, which stipulates that the plastic must stop burning within ten seconds and not produce any burning drips. In terms of electrical insulation, the new enclosures meet the requirements of DIN EN 61140 protection class II. They also benefit from UL 508A approval for the North American market.
FLEXIBLE AND VERSATILE
When it comes to the interior fit-out of plastic enclosures, the options have so far often been very limited, but it doesn’t have to be that way. For the first time, Rittal has replicated the system concept of its steel and stainless steel enclosures in plastic enclosures. This means the interior has numerous integrated mounting bosses, making it easy to screw on accessories such as support rails and door-operated switches. Universal brackets create the 25 mm pitch pattern that is familiar from the company’s large enclosures. This has the advantage that accessories for the VX25 large enclosure and the AX compact enclosure also fit in the plastic enclosure AX – from lights and punched sections to locking systems – for fast component installation and full design freedom during interior fit-out. The door provides an additional mounting surface in the form of its reinforcement frame, which can be very easily fitted with rails, punched sections, door stays or a wiring plan pocket. The mounting bosses eliminate the need for machining, without compromising the enclosure’s protection category. Mounting the enclosure on a wall or pole is equally straightforward, as the rear panel is equipped with press-fitted threads to accommodate screw fixings when attaching brackets.
FAST AND CONVENIENT
The enclosure’s mounting plate is included separately on delivery, which means machining and component mounting can start immediately. The process of installing a configured mounting plate is also very straightforward – it is simply pushed onto the threaded bolts and screwed firmly into place. The plastic enclosure has a symmetrical design, which means it is easy to rotate if necessary. What’s more, the door hinge is interchangeable, so it can be switched to the other side – even on site – in just a few simple steps.
