Avoid using IP54!
From experience we know that IP54 is not enough for dairy applications, which is why IP66 was selected as the standard alternative for field mounted frequency converters on process modules.
Furthermore, IP66 brings other benefits too:
Powder coated aluminum enclosure, making it washable with aggressive cleaning agents.
Corrosion protected fan, giving reliable operation in wet areas.
Rubber seal at LCP glued to LCP, withstanding water sparay according to IP66 and NEMA4X.