Saturday, April 6, 2013

Screw Compressor Inverter

Variable-speed drive (VSD) describes equipment used to control the speed of machinery. Many industrial processes such as assembly lines must operate at different speeds for different products.

Where process conditions demand adjustment of flow from a pump, varying the speed of the drive may save energy compared with other techniques for flow control.


Where speeds may be selected from several different pre-set ranges, usually the drive is said to be adjustable speed.

If the output speed can be changed without steps over a range, the drive is usually referred to as variable speed.

Source: http://en.wikipedia.org.
Starting a Motor
In starting a motor, a VFD initially applies a low frequency and voltage, thus avoiding high inrush current associated with DOL (Direct On Line starting.  After the start of the VFD, the applied frequency and voltage are increased at a controlled rate or ramped up to accelerate the load.

This starting method typically allows a motor to develop 150% of its rated torque while the VFD is drawing less than 50% of its rated current from the mains in the low speed range. A VFD can be adjusted to produce a steady 150% starting torque from standstill right up to full speed.

However, motor cooling deteriorates and can result in overheating as speed decreases such that prolonged low speed motor operation with significant torque is not usually possible without separately-motorized fan ventilation.
415 V --- 50 Hz Screw Compressor Inverter

 Model: HLPSKOO2243B
Power : 22 kW
Input Current : 41.2 A
Output Current : 43.0 A
Size: A120 X B150 X C313 X D335 X  E262 mm

Can be used on many standard Electrical Air Compressor's main motors

Benefits
Energy savings

Many fixed-speed motor load applications that are supplied direct from AC line power can save energy when they are operated at variable-speed, by means of VFD. Such energy cost savings are especially pronounced in variable-torque pump applications, where the loads' torque and power vary with the square and cube, respectively, of the speed.

This change gives a large power reduction compared to fixed-speed operation for a relatively small reduction in speed. For example, at 63% speed a motor load consumes only 25% of its full speed power





Model: HLPSK003743B
Power : 37 kW
Input Current : 70 A
Output Current : 73 A
Size : A200 X B292 X C500 X D530 X E210 mm

Energy cost saving of up to 50% based on 30% off peak operation.
Return on your investment in one to two years


Model: HLPSKOO5543B
Power : 55 kW
Input Current : 103 A
Output Current : 106 A
Size : A280 X B330 X C630 X D680 X E300 mm

Control Performance
Fixed-speed operated loads subject the motor to a high starting torque and to current surges that are up to eight times the full-load current. AC drives instead gradually ramp the motor up to operating speed to lessen mechanical and electrical stress, reducing maintenance and repair costs, and extending the life of the motor and the driven equipment.


Variable speed drives can also run a motor in specialized patterns to further minimize mechanical and electrical stress





Model : HLPSK007543B
Power : 75 kW
Input Current : 140 A
Output Current : 147 A
Size : A280 X B330 X C630 X D680 X E300 mm

The above are some examples only. Contact us for more details

Warranty :  6 months against Manufacturing Defects, from date of start up.
NOTE:
Price shown are for inverter unit only.
Conversion charges & stand will be charged separately.
Power cables from isolator to inverter, inverter to electric motor will be charged separately depending on size and actual length used.

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