VSD Sizing/Selection: Please see below guidelines and contact us for verification if necessary:
- For Hammer and Impact Crushers, consider using a Soft Starter instead of a VSD. VSDs are not recommended since the current tend to be very unstable during normal operation, which makes the VSDs prone to go into overload / overcurrent protection. If the feed to the Crusher is controllable (when the current is large, the feed speed should be automatically reduced), one can consider using a VSD, if it is not controllable, a Soft Starter is recommended. Some field conditions do however require the use of a VSD to reduce the impact of the starting current and some users therefor insist on using a VSD (instead of Soft Starter), and mostly use it without any problem (1/10 report overload), but this is then done using the correct design to ensure the feed is controlled.
- Select VSD (kW) of two sizes larger than the Motor (kW) for:
- Heavy/High Duty (Industrial) Applications (high torque requirement at start-up, e.g., Crusher, Ball Mill, Compressor with 6 Poles or more).
- Select a VSD (kW) size larger than the Motor (kW) for:
- General Duty Motors with 6 Poles or more (if torque is high).
- Low Duty (low torque requirement at start-up, e.g., Fan, Centrifugal Pump) Motors with 8 Poles or more.
- Low Efficiency Motors (e.g., submersible borehole pumps).
- For Crane/Hoist/Lift/Winch Applications (select a VSD model so that the Motor rated Amps is less than 70% of that of the VSD Output Amp rating and use Brake Units and/or Brake Resistors for quick stopping).
- For use in areas with altitude over 2000m or ambient temperatures above 40 degrees Celsius (preferably use forced cooling, ambient temperature must always be less than 50 degrees). Please Derating Specifications for more info as well as Cooling/Panel Fan Selection specifications.
Please Note:
- Up to 22kW models = Plastic Housing; 30kW+ models = Metal
- All EM15 models include RS485 terminals on the Control Boards (Modbus RTU Communication).
- Prices for spares available on request only (includes items such as keypad, control card, power card, IGBT model, fan, fan board, capacitor, rectifier).
- Please refer to each specific model’s User Manual for important details regarding product Installation, Setup, Safety Information, Precautions and Maintenance
- Use the VSD to Start and Stop the Motor, do not disconnect the supply from the VSD to the Motor while it is running. Also do not disconnect the power supply to the VSD while it is running the Motor.
- Do not use a VSD to run more than 3 motors simultaneously (For G1 and G13 Series VSDs, do not use more than one motor per VSD).
- Note that if the cable length between the VSD and Motor is more than 50m, we would also recommend that you install an Output Choke/Reactor, for cables more than 150m we recommend installing a SineWave Filter (instead of the Output Choke/Reactor).
- Please use Copper power cables between the VSD and Motor rather than Aluminium cables (impedance of Aluminium cables are higher and cause more harmonics).
- For installations in enclosures, device keypads can be removed and installed into enclosure doors using additional keypad frames and extension cables.
- Please see the VSD and Solar Drive Peripherals section of the VSD Manual for info on additional items that might be required for installation. Also see the applicable peripheral device manuals regarding information on these items.
- PG Cards (Pulse Generator Cards) are also available on request and can be ordered together with custom VSD Control Cards. EMHEATER PG4 Universal Expansion Cards can be ordered for OC Signal Input (No Frequency Division Output) or Differential Signal Input (with Frequency Division Output).
- Software is available for the G1 and G3 Series VSDs which enables the VSDs to be connected to a PC/Laptop via USB/RS485 or RS232/RS485 converter (not included). The software allows configuration and downloading of all the VSD parameters/settings.
