25
Section 6
VARIABLE SPEED DRIVE
KWH - Running total of energy used in kilowatt-
hours.
Cost - Running total of cost of operation.
Savings - Estimated savings compared to other
control methods.
The next eight lines indicate long-term perform-
ance during the entire life of the compressor.
Capacity - Average delivery in CFM.
Capacity % - Average percent of full package
capacity.
Power - Average total package power in KW.
Power % - Average percent of power at full capac-
ity.
KCF - Running total of air delivered in thousands of
cubic feet.
KWH - Running total of energy used in kilowatt-
hours.
Cost - Running total of cost of operation.
Savings - Estimated savings compared to other
control methods.
The last five lines indicate real-time control sys-
tem parameters for service evaluation.
P2 - System pressure.
Motor RPM - Motor speed.
Frequency - Output frequency of the drive in Hertz.
Drive Temp - Internal temperature of the drive.
Motor Prot - Estimated percentage of motor tem-
perature rise.
6.4.2 CONTROL PARAMETERS
The following adjustments apply specifically to VSD
packages.
Setpoint - The targeted pressure for the variable
speed controls. This is normally adjusted near the
bottom of the load/unload band above. The speed
will be adjusted to maintain this pressure. Most
packages will allow adjustment of this over a wide
range, to allow tailoring to the needs of the applica-
tion. Adjustments will be automatically made to the
maximum speed to operate the motor at its full
capacity at any pressure.
Cost/KWH - The cost per kilowatt-hour of energy is
entered here, for use in cost estimates in the VSD
Status displays. For example, enter 0.070 for 7
cents per KWH.
Saving vs - The basis for savings estimates. The
cost of VSD operation can be compared to Inlet
modulation, Load/Unload, or variable displacement
(spiral valve) control systems.
Reset Load Est. - This resets the "Recent Usage"
values to zero in the VSD Status calculations. This
functions similarly to a trip odometer in a car.
6.4.3 CALIBRATION
Two additional calibration adjustments are provided
in VSD. These can be used to fine tune nominal
values used in VSD Status displays. Each is
adjustable from 0 to 200% of nominal.
Cap - for adjustment of delivery values. This may
be used for adjustment to actual conditions, or for
display in other units of measure.
KW - This may be used for adjustment to calibrated
meters under actual operating conditions.
6.4.4 FACTORY SETUP
Factory adjustments are generally the same as
conventional packages, with a few additions.
Model - The features in this section apply only to
V120, V160, V200, V200S, and V200TS models.
These packages are designed specifically for inte-
grated drive control. This model selection will affect
the choices available in the VSD Setup group.
Capacity - This number will be adjusted, along with
maximum speed, whenever a change is made to
the setpoint pressure.
Spiral Valve - This should be set as appropriate for
the package. The spiral valve will be closed for
highest efficiency at all moderate to heavy
demands. The valve will be opened for light
demands.
VSD - The descriptions in this section apply only to
packages with integrated drive controls operating in
serial communications with the Supervisor.
6.4.5 VSD SETUP
This group of adjustments sets up the parameters
of the drive for the construction of the compressor
package. These may be viewed at any time, but
are protected by the password in the Factory Setup
group.
VSD Auto-Set - This should be set to "Yes" for all
normal applications. This performs automatic
adjustment of several parameters based on operat-
ing conditions and user adjustments.
Nominal HP - The nameplate horsepower of the
main drive motor.
Nominal Volts - The compressor package rated
nominal voltage
VSD Max Amps - The rated maximum current of
the drive
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