Emerson Vission 20/20, Operation And Service Manual

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6 – 6
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 2.0
Section 6 • Compressor Control
Figure 6-7. Compressor Control Screen - Rapid Cycling VFD Control
Rapid Cycling VFD Control
The VFD page is where the operator can tune the motor
VFD for desired rapid cycling VFD operation, see Figure
6-7. A Vilter compressor uses the variable speed of a VFD
controlled motor to vary the amount of work or capac-
ity of the compressor. The rapid Cycling VFD control will
keep capacity slide loaded to maximum and vary the
motor speed to achieve the required work or capacity.
For example, if the compressor needs to load to 100%
of its capacity. The control algorithm will keep capacity
slide loaded to its maximum position and ramp up the
motor speed up to its maximum speed. In the unloading
direction, the motor speed will ramp down to its mini-
mum speed, keeping capacity slide loaded to maximum.
In this manner, capacity load is handled by varying mo-
tor speed only.
VFD Speed Range:
• De
fi nes the Minimum and Maximum speed for the
motor speed. These values should re fl ect the full
range of the VFD.
Warm up Timer:
• De
fi nes the Warm up period for Compressor. This
timer gets activated after every compressor start and
remains active for the de
fi ned time. During this peri-
od, Oil Pump is turned ON and motor speed is varied
from 1200 RPM to 3600 RPM.
Oil Restriction Setpoint:
• This is Compressor VFD RPM setpoint used for turn-
ing ON/OFF Oil Solenoid Digital Output. Oil Solenoid
Digital Output is turned ON when Compressor is
Running, Warm up Timer is Lapsed and Compressor
VFD RPM goes below this setpoint.