IE2 definition

Definition of Low Voltage Squirrel Cage Motors according to IEC

Three phase motors (from 0,75 kW to 375 kW and 2, 4 or 6 poles) are according to IEC 60034-30 classified in efficiency classes (IE1 - Standard Efficiency, IE2 - High Efficiency und IE3 Premium Efficiency). This classification is valid for all stand alone motors (only stand alone motors can be tested according to the IEC - the motor needs two bearings) .
Since January 2017, according to regulations only IE3 motors can be sold, with the exception of motors with inverters, which can be sold with IE2 efficiency class.

Exception
Side channel blowers of the model-range SKV-NS, SKV-ND, SKV-NDF, SKV-HS, SKV-HD and SKV-HT are exempt from this rule, because:
- the above mentioned series have a product integrated motor (this motor can not be tested according to IEC because without the housing the motor is not working, with housing the motor can not be tested)
- integrated motors does not have a standardized motor flange according to IEC
- integrated motors have a special shaft (design and/or material)
For side channel blowers the IEC classification means therefore that the motors are designed the same as stand alone motors which would reach the IE2 classification.

Advantages of IE2 motors

• IE2 motors are larger at the same horsepower output (higher reliability)
  
• lower thermal load of IE2 motors increases the motors life time
  
• downtime and maintenance costs are reduced
• higher toleranze against overload, voltage peakes and surrounding temperature
  
• reduced electricity costs (lower current  = lower electricity consumption = reduced costs!)

Example for calculation of energy savings
Power = Current * Voltage
A current reduction of 0,1 A means:
P = 0,1 A * 400 V = 40 W
At one day (24 h): 960 Wh
For one year the reduction is: app. 350 kWh (per 0,1 A reduced current)
Example:
SKV-NS-210-3-936 - max current: 5,6 A
SKV-NS-210-3-836 - max current: 4,65 A
Reduction = 0,95 A and per year = 3.325 kWh/a
Amortisation: Reduction at 15 ct/kWh = 499 €/a - price for IE2 motor = 76 €