Motors for Cement and Aggregate Production

Frequently Asked Questions

• What is the practical difference between IE2, IE3, and IE4 efficiency classes?

• The difference is in the percentage of input electrical power converted to useful mechanical output, with higher IE numbers indicating lower losses. For example, a 75 kW 4-pole motor might have an IE2 efficiency of 94.1%, IE3 of 95.0%, and IE4 of 95.8%. This 1.7% difference from IE2 to IE4 translates to roughly 1.3 kW less loss under full load. Over 8,000 hours/year, this saves about 10,400 kWh, offering significant cost savings and carbon reduction. IE3 is now the legal minimum in many regions, while IE4 is specified for maximum savings.

• When should I choose a 690V motor over a 400V motor?

• Choosing 690V is advantageous in several scenarios: 1) For higher power ratings (typically above 200-250 kW), where 400V currents become very high, requiring large, expensive cables and switchgear. 690V reduces current, saving on distribution costs. 2) In plants with a 690V distribution system. 3) For long cable runs, where lower current reduces voltage drop. 4) When using a VFD, a 690V motor allows the use of a 690V VFD, which often has better performance and efficiency at higher power levels. The motor itself will be slightly more expensive, but system costs may be lower.

• Can a low voltage motor be used in a hazardous area?

• Only if it is specifically designed and certified as an explosion-proof motor. Standard low voltage motors are not suitable for hazardous areas. For such locations, you must select a motor from an explosion-protected series like our YBX3 or YBX4, which carry certifications (IECEx, ATEX) for specific gas groups and zones. These motors have reinforced enclosures to contain explosions, temperature-limited surfaces, and other safety features. Never install a standard motor in a classified hazardous area.