Jim, when would you choose the GS3 over the GS2? I understand the GS3 uses sensorless vector drive but is that a significant advantage? Beyond the basic drive, are there other components that are necessary to complete the installation? I don't mean to take up your time and I will call Automation Direct but your input would be valuable nonetheless.
Please feel free to ''take up my time'', that's why I joined this forum, to help out where I can.
I have both drives and use them based on the application. The GS2 is only Volts/Hertz output, in other words, it reduces the voltage as the frequency decreases. Thus the torque curve is variable and the low speed performance is not as good as a sensorless vector output, the GS3. I'm not going to try to explain how sensorless vector works, because I don't understand it myself
. It's electrical magic.
But the result is that the VFD has a lot more control over the motor and the torque can be constant from about 10 RPM up to the rated speed of the motor. Great for low speed milling. I just replaced the GS2 on my machine with a GS3 and am very happy with the result.
The GS2 is best used between 30 and 90 Hz. I am running the GS3 on my spindle between 10 and 200 Hz (180-6000 RPM, if I did the math correctly). Note: My motor is rated for 6000 RPM, I would not recommend this on a motor that you don't know the specs on. Running an 1800 RPM motor at 3600 RPM (120 Hz) is probably safe.
As for other components, a braking resistor is almost mandatory for reasonably fast stops. Then you
may need a small control panel with Start, Stop, For/Rev switches, and a Speed Control pot.
I mounted the GS2 right on my head in place of the original switch and just ran it from the control pad. I am used to reaching up into that area to run a BP type mill.
When I installed the GS3 I built this panel and installed the VFD on the back of the control cabinet.
Here is the BOM for the control box I built. Automation Direct parts.
Item Code | Unit Price | Quantity
ECX2300-5K $36.50 1
SA110-40SL $13.50 1
GCX1131 $12.50 1
GCX1102 $6.50 1
GCX1300 $9.75 1
E22NS31 $4.50 1
E22NS34 $4.50 1
E22NS38 $4.50 1
ECX2640 $3.50 1
Shipping and Handling : $0.00
Order Total : $95.75