A14/A18 The model A14/A18 is an asynchronous three-phase motor with a squirrel cage rotor, completely closed. Casing and shield are made of aluminium up to 132 dimension (A14), cast iron for the others (A18). IP55 protection degree (IEC 34-5), F insulation class and multi-tension for the whole range. These motors are designed to work at a max. ambient temperature of 40°C and a max. altitude of 1,000 m above sea level. Should these motors work at higher temperatures and/or altitudes, they generally would need to be derated.