Single-speed motors of sizes 56 to 132 are stamped with50 and 60 Hz at voltage codes S and D. The current rating for each voltage range is specified on the rating plate. It represents the highest current that can exist within the voltage range at the rated output. The power factor and speed specified on the rating plate apply at 400 V 50 Hz and 460 V 60 Hz. M3AA 280 has feet and a D-end shield of cast iron. M3AA 250 SMB 2-pole, high output version, as well as M3AA 280 2-pole have cast iron feet and bearing shields. The flange bearing shields of sizes 180 to 280 are made of cast iron Axially-locked bearings.
The terminal block is provided with 6 terminals for connecting Cu-cable. The terminals are marked in accordance with IEC 60034-8. Single-speed motors of sizes 160 to 280 are stamped with 50 and 60 Hz at voltage codes S and D. The rating plate is arranged in the form of a table with values for current, power factor, and motor speed at six voltages.
Motors that will be operated in very humid or wet environments and especially under intermittent duty should be provided with drain holes. The appropriate IM designation, such as IM 3031, is specified on the basis of the method of mounting the motor. Motors are provided with closable plastic plugs in the drain holes (see diagram below). The plugs will be open on delivery. When mounting the motors it should be ensured that the drain holes face downwards. In the case of vertical mounting, the upper plug must be hammered home completely. In a very dusty environment- ments both plugs should be hammered home. Sizes 56 to 63 are supplied as standard with drain holes on D-end while sizes 71 to 280 are supplied with drain holes both on D-end and N-end. When mounting arrangement differs from foot-mounted IM B3, please mention variant code 066 when ordering. See variant codes 065, 066, and 076 under the heading“Drain holes”.