The speed written on the product label of the electric motor shows the speed when it is worked with 50 Hz and 380 Volt.This speed is constant.You can not change it because our Frequency and voltage are constant.
However standart motors work with 50 Hz or 60 Hz ,in general motors can work with up to 400 Hz by invertor. Vortex Variable Speed Drive (VSD) compressors use German KEB Frequency Invertors.
The Advantages of VSD Compressors
Electric Costs View :
Standart Rotary Screw compressors working with a full load,no load control operate between two set pressure points.When maximum pressure is reached,the compressor goes off load.During periods of medium to low air demand,the no load power consumption can be excessive wasting glarge amounts of energy.
You lower energy cost with VSD because there is no unnecessary power generated, Vortex VSD can reduce energy costs by 35 percent or more.Lifecycle costs of the compressor can be reduced by an average of 25 percent.In general ,the extra cost of a VSD compressor compared to fixed speed one can be earned back after jsut one to two years.
| Substation View :
At initial starts ,electric motors use up to four times higher current than it is at normal running.That situation can give harm to company’s Substation.The capacity that the substation supplies for the Compressor Unit is constant. At initial starts ,other electrical components can be cut for a short time.That can give harm to your other machines which use electricity.Variable Speed Drive Compressors prevent this situation with soft-start function.
Compressor Function View :
The maximum pressure that compressor produced is constant.The designated pressure is supplied with a series of calculations.Air-end pulley,Electric Motor Pulley dimensions are choosen for this designated pressure.At invertorless compressors you can get pressures higher than your maximum set value but with VSD Compressors you can change your Air-end rpm and so you can get higher maximum pressure set.
For standart rotary screw compressors , you can stop and restart electrical motor for only ten times per hour.The life of the electrical motor is calculated due to this criteria.But for VSD compressors this number is infinite.
Compressor pulleys are faced with high mechanical stresses at the start,this situation is not valid for VSD compressors.Soft start prevents this.
There are lots of causes to prefer Vortex VSD compressors