OKW Enclosures’ marketing director, Robert Cox, guides readers through the process of specifying DIN rail enclosures such as the company’s RAILTEC B.
It’s easy to take DIN rail enclosures for granted because of their ubiquity and design similarities. However, they are not all created equal—so it pays to be meticulous when specifying.
Subtle differences in design and functionality can have a significant impact on ease of installation and maintenance—and ultimately how well the enclosures perform, especially in challenging locations.
Furthermore, there are advantages to be gained from specifying enclosures from a manufacturer that offers a wide range. It avoids having to deal with multiple suppliers, offering economies of scale and saving time.
As with any enclosure, the first question should always be: what’s it for? Given the enclosure will almost certainly be fitted to a DIN rail, the answer might initially seem obvious. However, will the device be used for termination, or will it be for a standalone instrument?
OKW’s RAILTEC B enclosures for TH35 rails now include a space-saving flat-profile variant for devices that do not require multiple terminations. It has a recessed operating area that can house a display and/or a membrane keypad. The ends are closed for mounting connections and interfaces (USB, D-sub, power supply).
DIN rail enclosures (DIN EN 60715) should be fully insulated and protected according to VBG 4 and IEC 529/DIN VDE 0470-1— and mountable either on rails or directly on walls. The enclosures should be available in widths from two to 12 modules, with flat and high connection levels, and in 5.0/5.08mm pitch for PCB terminal blocks and plug headers.
Ideally, these housings should offer the option of ventilation slots for optimum heat dissipation. This should be a standard feature to minimise the amount of custom machining required. Inside, a good DIN rail enclosure will have both PCB fixing pillars and guide rails. Flexible assembly should allow PCBs to be positioned in all three directions. The DIN rail clip should be pre-assembled into the base to save time.
DIN rail enclosure ranges should feature plenty of versions to suit a broad spectrum of requirements. Consider configurable variants that enable the addition of terminal blocks and guards, partition plates, plug headers, front panels and transparent or translucent lids. Other accessories can include wall suspension elements and KNX covers.
Housings moulded from flame-retardant polycarbonate (UL 94 V-0) will be tougher than ABS enclosures—PC is the plastic used for riot shields and bulletproof glass. Ingress protection should not be an issue if the enclosures are installed in IP-rated cabinets. OKW Enclosures’ marketing director, Robert Cox, said: “Customisation is also an important consideration—even though the large number of standard variants reduces the amount of modification work needed.”
In-house customisation services at OKW include machining, lacquering and decor foils, plus laser marking and digital printing, which make it quicker and easier to add consecutive numbering and barcodes.