This is a totally enclosed fan cooled 3-phase 4-pole induction motor with rated output 3 hp, rated speed 28740rpm in foot mounting. It can widely used in various kinds of general purpose machineries like fans, pumps, compressors, machine tools, transportation, etc.
3hp Induction Motor Specification
||Horizontal Foot Mounting (B3)
||Output≤4hp (3kW), Y connection
Output≥5.5hp (4kW), Delta connection
|Degree of protection
||TEFC (compliance to IC 411 code of IEC 60034-6)
||3.0hp or 2.2kW
|Nominal Current (full load)
|Power Factor( cosφ)
|Nominal Torque (Tn)
|Locked Rotor Torque/Nominal Torque (TST/Tn)
|Maximum Torque/Nominal Torque (Tmax/Tn)
|Locked Rotor Current/Nominal Current (IST/In)
||Less than 1000m above sea level
3-phase Induction Motor Dimensions
||Mounting Dimensions (mm)
Wiring Diagrams (Three-phase squirrel-cage induction motor)
Tips: Three-phase induction motor’s speed control method
Three-phase induction motor speed is calculated: n = 60f (1-s) / p
It is seen from the above formula that changing power supply frequency f, motor pole pairs p and slips can achieve the purpose of changing the rotate speed. From the perspective of the nature of speed control, different speed control methods are nothing more than changing the synchronous speed of alternating current motor or not changing the synchronous speed. The speed control method of not changing the synchronous speed is widely used in manufacturing machinery including series resistance in the rotor of wound-type motor, chopper, cascade and electromagnetic slip clutch, hydraulic coupling, oil film clutch etc. Changing the synchronous speed consists of multi-speed motor of stator pole pairs, stator voltage and frequency conversion etc.
In views of energy consumed at speed control, there are two types including high-efficiency speed control and low-efficiency speed control. High-efficiency speed control refers to constant slip or non-slip loss, such as multi-speed motor, frequency control and control method of recovering the slip loss (for instance cascade speed control etc.). Slip loss speed control method is inefficient for example energy loss occur in the rotor circuit by the speed control method of series resistance in the rotator; Energy loss happens in the clutch coil by the speed control method of electromagnetic clutch; energy loss takes place in the hydraulic couplers oil by the speed control method of hydrodynamic coupling. Generally speaking, the slip loss increases with the expansion of speed range. If the speed range is not large, the energy loss will be very small.