EMHEATER offers 3 different Solar Drive (Solar VSD) models as follows:
- SP1S: Solar DC 300-380V (or Single-Phase AC ~220V) Input and Single-Phase (~220V) AC Output
- SP1: Solar DC 300-380V (or Single-Phase AC ~220V) Input and 3-Phase (~220V) AC Output
- SP3: Solar DC 450-650V (or 3-Phase AC ~380V) Input and 3-Phase (~380V) AC Output
For Solar Drive 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 Solar Drive.
- For the SP1S Series, note that some of the Single-Phase Motors have very high Amp ratings, so make sure the Amp rating of the Motor is less than that of the selected Solar Drive, otherwise select a larger kW Solar Drive.
- Select Solar Drive (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 Solar Drive (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 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).
For Solar Array Sizing/Design, there are 2 critical aspects to consider during the design process:
1. Minimum PV Array Voltage
This is dependent on Solar Drive Series used and has minimum start-up voltage requirements, maximum voltages allowed and suggested voltage ranges for optimal performance. Voltages for each series as follows:
- SP1S
- Minimum Start-up Voltage: 120Voc
- Maximum Allowed Voltage: 400Voc
- Ideal Voltage Range: 250Voc – 380Voc (300–380 if possible)
- SP1
- Minimum Start-up Voltage: 120Voc
- Maximum Allowed Voltage: 400Voc
- Ideal Voltage Range: 250Voc – 380Voc (300–380 if possible)
- SP3
- Minimum Start-up Voltage: 280Voc
- Maximum Allowed Voltage: 750Voc (above 800Voc will cause damage to drive components)
- Ideal Voltage Range: 350Voc – 650Voc (450–650 if possible)
- SP1S
* Please note that Solar Panel Voc ratings are based on specific test conditions and can provide higher Voltage outputs under ideal conditions, which would increase the overall Array Voltage output. Ensure that the design allows for this and that it will never exceed 800Voc (otherwise the Solar Drive components will be damaged).
2. Minimum PV Array Power (kW)
The total PV Array kW requirement is dependent on the Solar Drive kW rating – should be at least 1.3 x the Solar Drive kW rating. This should however ideally be more than that depending on the required working hours per day or other aspects such as minimum pressure required for pumping solutions etc. This is to ensure the system can provide enough working hours in the day which will fluctuate based on the PV Array output during different seasons of the year and at different hours and conditions of each day. Most installers prefer a ratio of a PV Array kW size of 2 x that of the Solar Drive kW rating. For the smaller drives (0.75kW up to 2.2kW) it could be better to use High Voltage panels to reduce the number of required panels.
Solar Drive PV Array Design Tool
To assist with the calculations based on the specifications of the selected EMHEATER Solar Drive, Motor and PV Panels, the following Excel calculator can be used to simplify the design process: Excel Calculator (the min/max voltage requirements varies for the SP1/SP1S and SP3 models – for all models the PV Array kW should be at least 1.3 times the motor kW).
Please Note (Solar Drives):
- Multiple Solar Drives can be connected to a single PV Array, but in the event that the Solar Drives are set up to automatically start and stop based on available sunlight, adjust the Sleep and Wake Up Voltages of the various Solar Drives so that they don’t Start and Stop at the exact same time (cannot combine SP3 Solar Drives with SP1 or SP1S Solar Drives using the same Array due to the variance in Array Voltage requirements).
- If you want to use the Solar Drive with AC input as well (Solar Assist Mode), you also need to install Diodes to protect the PV array (some of the smaller kW ranges only allow for a single power supply though). Please see the Solar Assist Mode FAQ page Entry for more details regarding PV Array Design requirements relating to Solar Assist Mode applications.
- Note that if the cable length between the Solar Drive 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 Solar Drive and Motor rather than Aluminium cables (impedance of Aluminium cables are higher and cause more harmonics).
- Use the Solar Drive to Start and Stop the motor, do not disconnect the supply from the Solar Drive to the motor while it is running. Also do not disconnect the power supply to the Solar Drive while it is running the motor.
- When using any of the Relays, note that for Smaller Drives with only one set of Relays (TA-TB-TC), use the TA2-TB2-TC2 Relay parameter settings.
