Characteristics of three-phase motors:
Depending on the size, the engine bodies differ in construction material. Up to size 132, they are made of light aluminium alloy, directly connected by stator magnetic plates (packets). For sizes 160 to 355, both the housing and the shields are made of cast iron with alloy additions, thus forming a whole.
Impeller and output shaft
All motors have aluminium double impeller cages. The impeller is dynamically balanced and the vibration degree corresponds to the “N” value. At customer’s request, we can supply motors with vibration degree equal to “R” or higher. Vibration is measured according to international standard ISO2373. The output shaft is made of C40 steel for a whole range of mechanical sizes.
The motor junction box, with a mechanical size of 56 to 180, is located at the upper part of the motor housing, and the openings for the power cables can be oriented in different directions. With motor sizes from 200 to 355, the junction box is usually located on the right side of the motor housing and can be rotated to 4 position every 90°. All engines are equipped with a 6-terminal block connection.
Depending on the size, motors have different bearings. From sizes 56 up to 180 they are fitted with maintenance-free ball bearing, and sizes 200 to 355 in open bearings with lubricators.
Degree of Protection (IP)
The appropriate degree of protection provided by the housing of the electrical device is a necessary condition affecting the service life and proper operation of the motor. About the appropriate degree of protection decides the intended use and the motor operational environment.
The degree of protection specified by the IEC 34-5 standard is specified by the distinctive “IP” symbol (“International Protection Rating”, sometimes “Ingress Protection Rating”). It is described by a code that indicates the degree of protection provided by the housing:
– the first digit indicates protection against accidental contact with foreign bodies,
– second digit means protection against the effects of liquid penetration,
– the third digit defines mechanical protection.
All motors are built as standard with IP 55