Advertorial - There's more to installing drives outdoors than IP ratings
Variable speed drives (VSDs) are not generally designed to be exposed to the elements of nature and so for a drive operating outdoors we frequently see the highest rated drives specified. However, protection against ingress of dust and water alone is not enough to keep a drive running optimally in all weather, as ABB’s Oliver Woolley explains.
Drives for HVAC applications are routinely installed outside, and as such can be exposed to the outdoor elements. It can be tempting to specify a drive with a high ingress protection (IP) rating on the basis that this will protect it against the weather.
However, IP ratings won’t protect a drive against direct sunlight. UV rays will over time damage the drive’s plastic casing and keypad displays, and sunlight can also cause the drive’s operating temperature to significantly increase. This can cause issues with heat dissipation, reducing the drive’s efficiency and potentially shortening the lifespan of components. UV can also damage any exposed cabling. For this reason, we recommend that outdoor drives are mounted north-facing where possible and installed in a suitable
protective enclosure to limit the amount of direct sunlight they receive.
Extreme cold can also cause problems. IP does not, for instance, combat frost and snow resting on auxiliary fan blades. Internal components can be at risk of water damage caused by water condensing out of the air once temperatures reach “dew point”. In general, this situation can be avoided simply by installing the drive(s) in a suitable protective and weatherproof enclosure and keeping the drive powered on at all times, as the heat generated by the drive’s electronics will prevent it from freezing. If maintenance must be carried out, then take care to ensure that frost and condensation do not form while the drive is powered off.
Drives need a regular supply of air for cooling. Installing outdoors runs a higher risk of insects, debris and, as mentioned above, even snow or frost blocking the drive’s incoming and outgoing airfl ow. To prevent this, again consider installing the drive in a protective enclosure, and inspect it regularly to ensure that air channels are not blocked.
To sum up, ingress protection is not the same as weatherproofing, and the best way to protect a drive outdoors is to install it within an appropriate protective enclosure. Specifying and installing the correct solution at the earliest opportunity during the project design stage will prolong the drive’s lifetime and improve its sustainability, while still providing full protection against the famously unpredictable British weather.
If you have any questions about using drives in outdoor environments or wish to find out more about ABB’s weatherproof cover for ACx580 drives, contact me on oliver.woolley@gb.abb.com.
