ELECTRIC STANDARDS
Italy CEI 2-3, Issue 1, 1974 - Publ. 355 - International IEC 34-1 - Belgium NBN 7 - France UTENFC 51-100 - Denmark DS 5002 - Germany VDE 0530 - Great Britain BS 2613 - Holland NEN 3173 - Sweden SEN 260101 - Switzerland SEV 3009.

MECHANICAL STANDARDS
Italy UNEL 13113/71 for B3 shape - UNEL 13117/71 for B5 shape - UNEL 13118/71 for B14 shape - International IEC 72 - Germany DIN 42673 - Great Britain BS3979.

Following data are given on the rating plate: characteristics for continuous rating, rated voltage, 50 cycle frequency, max. environment temperature 40°C and altitude up to 1000m a.s.l.
The motors are normally wound for a voltage comprised between 220 and 500V. According to IEC standards they can withstand a variation in the rated voltage of ±5% with an increase in temperature not exceeding 10°C.

GENERAL CHARACTERISTICS
All motor are enclosed, with external superficial ventilation squirrel cage-type rotor and frames comprised between 63 and 132mm.

CONSTRUCTION DETAILS
The frame, the front and the back shields are made of die casting aluminium alloy. The rotor pack is of the squirrel cage type made of die casting aluminium; the shaft is made of C40 steel; the rotor is dynamically balanced.
Radial, double-shield bearings with self-lubricating balls are foreseen for all size frames. The bearing at the non-drive end is assembled with a pre-tensioned spring, the purpose of which is to compensate for the axial gap and to minimise the vibrations.
The lid of the terminal box, made of plastic material or of die casting aluminium, is placed on the top of the motor and encases terminal-board made of phenol material. An opening on the motor frame is normally foreseen for the entry of the feeder cables which are complete with cable tighteners or a sealed passage.
The fan with radial blades is made of polypropylene and uses a fan cover made of galvanised high-resistance steel. The stator with winding insulated according to B or F classes of temperature. The windings are impregnated with a class-H resin which guarantees high resistance to vibrations, considerable heat absorption and a long life-span.
The degree of protection is IP44 according to IEC 34-5 standards; on request IP45 for motors operating in the open air.
The motor noise levels are within the limits set by the IEC 34-3 and the ISO-R-1680 standards.