A European standard for metric thread gland screw couplings comes into force soon. This report explains what it means for contractors.
The demise of the PG steel armoured pipe thread and the introduction of EN 50262 for the replacement metric threads will mean an important conversion process for manufacturers and contractors.
From the year 2000, only cable screw couplings with metric threads can be designed or used in new products. This will apply to all conduit entries, for example in switch cabinets, distribution casings, surface mounted boxes, domestic connection boxes, installation sockets and equipment casings. The familiar PG7 and PG48 sizes will be replaced by M12 to M63 threads, while additional sizes from M6 to M75 have also been included in the new EN standard.
Given the large user base of PG design threads, the industry is being given time to adjust to the changeover. While EN 50262 takes effect from the end of December, PG cable screw couplings can be supplied as replacements for existing products until the end of March 2001. Alongside the old VDE 0619, the current test standard for PG cable screw couplings will also be withdrawn.
The introduction of the new standard will mean that threads throughout Europe and the Commonwealth will be uniform, though it will not be an international standard as the USA continues to use imperial standards. However, while the USA is not adopting the metric thread, we have noted an increasing demand for such products.
Another benefit is that EN 50262 is a safety standard, not just a construction standard, stipulating dimensions like the old DIN 46319 or DIN 46320. The only dimensional condition in EN 50262 relates to the interface of screw coupling to casing, the thread or bore, giving freedom when designing gland functions.
Yet the demand so far for metric threads in the light of impending change has been below our expectations. This, we believe, is mainly the result of a lack of information about the conversion, perhaps not surprising since EN 50262 was only published in March. Despite an apparent resistance to change from European users, the PG thread's days are numbered.
What's New In Industrial Applications
Erma cable terminations, from Sicame Electrical Developments, are hot-pressed from copper blocks and machined accurately to size. They offer higher short circuit ratings, lower on-load temperatures and greater stability than fittings pressed from tube. The thickness and width are not limited by the barrel dimensions and the larger cross-section lowers the through-current resistance.
Timetable For Change
After 31 December 1999 the standard DIN 46320 will be replaced by EN 50262 for metric thread gland screw couplings. However, PG cable screw couplings can still be supplied as replacements for existing products until the end of March 2001. Alongside the old DIN standard, VDE 0619, the current test standard for PG cable screw couplings will also be withdrawn in March 2001. The standard will apply to Europe and the Commonwealth, but is not international.
It’s all part of the process
Drake & Scull has launched a Process Services (DSPS) group to install high purity pipework systems in ultra-clean environments such as microelectronics and pharmaceutical production plants. DSPS also conducts audits and factory inspections. “We will go to a materials supplier and make sure the equipment it provides is manufactured and stored under the correct conditions,” says spokesperson David Orrell. “We will meet with clients and look at the most cost-effective way to deliver the system. We guarantee that all the materials we install are manufactured to exacting standards.” DSPS can also check pipework for leaks and test for particulates. It also offers complete traceability throughout the installation so that it can identify particular welds carried out on particular days.
MTE’s E-Pack
MTE’s E-Pack family of motor control products has been extended to include machine safety products. Safety relays, grab wire switches (pictured), tongue interlocks, magnetic and coded interlocks, position switches and emergency dc brakes are listed in the company’s new Safe-Pack leaflet.
Icore’s range
Icore’s range of heavy duty screened conduit now includes limited fire hazard, neoprene and super screened types with bore sizes from 0·5-2 inches. Kafon 2000 lfh conduit is available in a variety of braids and sheaths and is approved for operation from -55°C to 150°C.
Moeller
Easy to install, easy to operate and extremely flexible is how Moeller describes the SL family of signal towers which give clear indication of the operating status of machines and automated process sequences. Continuous light, flashing light, strobe light or an audible alarm are all indicator options.
Contactum
Contactum has launched a range of white distribution boards, with wiring space below, above and to the sides of the busbar assembly. A removable sub-plate is provided to ease mounting and single rows of terminals simplify connection. The boards are available from four to 16 TP ways with ten incomer options.Hellermann Tyton-BHD
With the football season in full swing, Hellermann Tyton-BHD is kicking off with an industrial kit promotion which includes a free, full-sized, hand stitched football and chance to win any team football shirt. The promotion runs to the end of October and is available through electrical wholesalers.
