The NEMA 4 LCD Enclosure by Richard N Williams

Posted by: Richard Williams | Posted on: October 24th, 2009 | 0 Comments

LCD enclosures have helped the digital signage revolution expand into outdoor environments. Protecting LCD and plasma screens from the elements, LCD enclosures ensure any outdoor digital signage is waterproof and protected from other harmful elements such as dust.

However, a manufactures’ claims that their LCD enclosure is watertight can only be tested once the LCD enclosure is installed and has endured its first rainstorm – and if it fails to will have proved an awful waste of time and money installing the device.

To ensure quality in the manufacturing of LCD enclosures, the trade association NEMA (National Electrical Manufacturers Association) has issued guidelines and standards for the manufacture of enclosures for outdoor and industrial use.

For outdoor digital signage requirements such as using an LCD enclosure outside the NEMA 4 standard is most applicable. NEMA 4 states that:

‘Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, and hose-directed water; and that will be undamaged by the external formation of ice on the enclosure.’

A NEMA 4 LCD enclosure will therefore be manufactured to the NEMA guidelines ensuring that any water or wind blown particulates are kept out of the device and ensure it will operate in these types of conditions. However, NEMA 4 is limited to the amount of protection that the enclosure offers. For instance, a NEMA 4 enclosure will not necessarily be manufactured to operate in extreme temperatures of either hot or cold and furthermore, NEMA 4 offers no guidance on the security and ruggedness of the enclosure.

When buying an LCD enclosure for outdoor use it is important therefore to consider the device is manufactured to NEMA 4 standard but also, if it is to be used outdoors in locations where extreme temperatures may occur then the enclosure will need adequate heating and cooling systems internally fitted.