Protect Your Connectors: Specify the Right Plastic Enclosure
December 9, 2024
SAFEGUARD FRAGILE PLUGS AND JACKS
Good enclosure design means protecting not just the components inside but also any connectors being plugged into the device. A protruding plug can all too easily fall victim to accidental impact. This force can then be transmitted to the jack, damaging it and possibly any other nearby components.
Connectors can be knocked during handling, transport or use – damaging the pins, housings or solder joints. Excessive stress from plugged-in cables being pulled or twisted can also cause damage.
The obvious solution is a deep recess to help shield connectors from impact. Recesses are simple and effective but they can mean sacrificing enclosure capacity. So achieving the right compromise can be a fine balancing act.
And although recesses are important and effective, they’re not the only line of defence. There are other considerations too, such as protective covers (for ease of access during maintenance), reinforced connector mountings, and cable strain relief.
DEEP RECESSES FOR OPTIMUM PROTECTION
Given the obvious requirement for safeguarding connectors, you would expect lots of standard enclosures to have deep recesses. Surprisingly not: there are far more enclosures out there with a recessed top for a membrane keypad – but no protection for any connectors.
One model that does have a deep recess is PROTEC (IP 65 optional), a desktop/wall-mount touch screen enclosure with a large square operating area on the top and a deep recess in the base section.
That recess can be hidden by a choice of two covers, both of which create extra space for components. This means that three versions of PROTEC can be specified for different applications within the same work environment: they all match, they all share the same design language.
Another example is SOLID-BOX (IP 66, IP 67, IK08). These tough enclosures for industrial electronics feature two deep recesses on the long sides, offering plenty of space for plugs, jacks and cable grommets.
And both PROTEC and SOLID-BOX illustrate another key point: simply adding a recess is not enough. The enclosure material must be sufficiently sturdy if the edges and corners of the recess are to provide any meaningful protection…
PROTECTIVE RECESSES WITH REMOVABLE COVERS
Some wires and cables can be more time-consuming to connect than others. Analogue VGA connectors spring to mind…though these days they’ve been largely superseded by digital interfaces such as DVI and HDMI.
However, it may be an advantage to specify an enclosure that has a recess with a removable cover. This allows greater access to the connectors – speeding up installation, inspection and maintenance.
One such enclosure is the slim, stylish and discreet NET-BOX (IP 65 optional) for building management systems, IoT/IIoT, Smart Factory and data systems engineering. Its removable cover conceals not just the recess and the connectors but also the mounting screws. No screws are visible from the front; the screws that hold the removable cover section in place can be seen only from the underside. And for the record, NET-BOX is molded from ASA+PC (UL 94 V-0) as standard.
HANDHELD ENCLOSURES WITH RECESSES
Remember that point earlier about few enclosures having deep recesses for connectors? This is particularly true of handheld housings. But examples do exist (especially if you opt for a larger model).
However, they’re not common. The nature of handheld electronics usually restricts these enclosures to the size of the human hand because they must be comfortable to hold and operate. Any larger and they cross the blurred line that separates handheld from portable devices.
But models such as HAND-TERMINAL (IP 65 optional) make a virtue out of being larger and yet still ergonomic. They’re capacious but remain light and pleasant to operate because they’re well balanced.
In the case of HAND-TERMINAL, some of that equilibrium is down to strategically placed recesses. Each long side has a recess for buttons and other controls – ensuring they’re always within easy reach of the thumb and fingers.
The third recess on these PC+ABS enclosures is at the front. And the top overlaps at the back too, at the point nearest the wrist. This creates a smaller recess, should it be needed. There are also two large flat surfaces that can be a good location for a big emergency stop button.
PULL/STRAIN RELIEF AND CABLE GLANDS
There’s little point safeguarding the cable entry aperture if the wire itself remains a weak point. Cables must be protected from pull forces and also from being weakened internally by bending or twisting at severe angles.
Pull-relief or strain-relief clamps will hold a cable in place securely. And a flexible gland will brace the cable as it bends, transforming a sharp 90° angle into a more graceful curve that doesn’t damage the thin wires inside the insulation.
If using cable glands, specify one that complements the ingress protection and flammability resistance of the enclosure. Many cable glands are molded from polyamide. PA is specified for cable glands because it is strong and resistant to chemicals, corrosion, heat and cold. Some types – such as PA12 – absorb less moisture than P6 or PA66 so they’re well suited to wet environments.
Not all cable glands are made equal. Quick-fix cable glands can speed up the installation process. And pressure compensation cable glands are recommended for protection against condensation in hermetically sealed enclosures in the event of temperature fluctuations.
View cable glands and pull/strain relief clamps >>
CUSTOMIZED PLASTIC ENCLOSURES WITH RECESSES FOR CONNECTORS
All OKW standard enclosures can be supplied fully customized so they arrive ready for the installation of your electronics. Customization services include CNC machining, lacquering, printing, laser marking, decor foils and RFI/EMI shielding.
Enclosures can also be specified in special materials. This enables you to substitute the standard plastic for a stronger and/or more UV-stable polymer. Custom colors can also be added at the point of moulding, rather than afterwards with lacquering or foils.
View OKW’s customization services >>
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