What is a VFD, and is it different from a VSD?
A variable frequency drive (VFD) controls an AC motor’s speed by varying the frequency and voltage supplied to it. Variable speed drive (VSD) is a broader term; Australian buyers often use both terms when looking for an AC motor drive. The drive must be selected for the particular motor and load, rather than purchased on the name alone.
For a pump or fan, speed control can help match output to demand. For a conveyor or mixer, the load may require different torque and duty characteristics. Energy savings and performance depend on the application; a VFD is not a guaranteed saving on every motor.
Does the ZK SG600 need solar panels?
No. Solar is optional. The SG600 can be used with an appropriate AC mains supply as a motor drive. ZK also describes solar MPPT and AC/DC supply operation for this series. A solar pump inverter is therefore not necessarily a solar-only device.
Decide whether you need mains operation, solar pumping or a supported AC/PV arrangement before choosing the model. Do not assume a solar feature makes the drive a battery inverter, a grid-export inverter or a universal single-phase-to-three-phase converter.
Our ZK SG600 model and price list covers the 4T range we supply. Confirm the exact input, output and installation requirements before ordering.
Choose by motor current as well as kW
The kW label is a starting point, not the entire selection process. Compare the motor’s nameplate voltage and full-load current with the drive’s rated output and the manufacturer’s duty rating. A matching kW value does not establish suitability when the motor current, supply or operating conditions differ.
- Motor: record kW, voltage, rated current, frequency, motor type and the connection shown on the nameplate.
- Supply: confirm voltage, available phases and whether operation will use AC mains, solar or a supported combination.
- Load: describe the pump, fan, compressor, conveyor or other machinery, including starting load and operating hours.
- Environment: note enclosure location, heat, dust, moisture, ventilation and cable distance.
- Controls: identify any pressure sensor, float switch, speed reference, remote start/stop or communication requirements.
Your electrician or drive specialist should confirm protection, earthing, isolation, wiring and applicable requirements. Do not connect or change settings using a generic internet guide.
For solar pumping, verify the exact array limits
PV array design needs more than a panel count or a simple ratio to motor kW. The applicable drive manual, panel specifications and site temperatures must be checked for maximum open-circuit voltage, operating voltage and permitted current. A general series-wide voltage range is not an array design limit for every model.
Send the panel model, quantity and proposed arrangement with your enquiry. We will confirm the relevant product documentation before quoting a configuration. Solar design and installation remain work for an appropriately qualified contractor.
Buying a drive in North Queensland or elsewhere in Australia
Evolve Energy Hub supplies SG600 hardware Australia-wide, including enquiries from Cairns, Townsville and the wider North Queensland region. Send your delivery postcode so availability and freight can be confirmed in the quote. We do not claim a local branch or guaranteed delivery time.
For a replacement, include the existing drive model and a photo of the motor plate. For irrigation or bore pumping, also include the required flow and head, and the pump details. See our North Queensland VFD supply page for the regional enquiry checklist.
Manufacturer references
- ZK SG600 series overview: solar MPPT and AC/DC supply operation
- ZK general MPPT guidance — confirm model-specific limits before using it for design.
This is a hardware buying guide, not a wiring, commissioning or electrical design instruction.