Well we have another GSHP running. The Varible Frequency Drive (VFD) is sooo smooth with the way the motor ramps on start-up. Of coarse you can control the presure with the speed. The scroll compressor is soo quiet. It is just running on the bench with no heat exchanging fluids so temps and pressures went crazy after 1 min.
I had programmed in a ramp to 3450 RPM in 5 sec and a ramp down to 0 RPM in 10 sec. If the motor becomes overloaded it will shut down. As the motor is starting you can watch the LED read-out with the current voltage RPM as they change. You can set a fault to wait on re-start. There are so many great capibilities with the VFD. It has low voltage input for the thermostat control. I may have to wait till the weekend to install the GSHP with the loop connections.
Randen
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