VYPER
™
VARIABLE SPEED DRIVE
OPERATION
100-210 IOM (JUL 09)
Page 36
OPERATION
Do not attempt to operate the
Vyper
™
Drive before performing proper setup
the
Frick Quantum
™
LX control panel.
Failure to do so may result in damage to the unit
.
QUANTUM
™
LX CONTROL PANEL
This section is provided to briefly familiarize the operator
with the user interface of the Frick Quantum
™
LX control
panel. Frick document: S90-022 0, “OPERATION – SER-
VICE, FRICK
®
QUANTUM
™
LX COMPRESSOR CONTROL
PANEL” provides detailed information about operation and
settings of the Quantum
™
LX Control Panel.
VYPER
™
OPERATION
Relying on user input as well as system pressures and
temperatures, the Quantum
™
LX directs the Vyper
™
to start
or stop the compressor as well as change the compressor’s
speed to regulate capacity. The setpoints that primarily control
the operation of the Vyper are found on the Quantum
™
LX’s
Capacity Control Setpoints and Motor Setpoints Screens.
When the operator initiates a system start command (lo-
cally or remotely), the Quantum
™
LX sends a signal to the
Vyper
™
to operate the motor. When the Vyper
™
receives
this command, the Vyper
™
begins a precharge process and
prepares to start the motor. During the precharge process
the cooling pump is switched on and the DC link voltage is
slowly increased. After approximately thirty (30) seconds, the
Vyper
™
turns on the motor and ramps up to the speed set by
the VFD “Minimum Drive Output” setpoint. Simultaneously, if
the slide valve is below the Variable Speed Minimum Slide
Valve Position, the Quantum
™
LX immediately loads the slide
valve to the programmed “Variable Speed Minimum Slide
Valve Position” setpoint.
As more capacity is required, the Quantum
™
LX loads the
slide valve. The “Capacity Control” settings (on the Motor
Setpoints Screen) can be configured to cause the motor
speed to increase at the same time, but in most Vyper
™
applications the capacity control “Drive Speed” setpoint is
set to match the “Minimum Drive Output” setpoint. In this
configuration, the motor speed will remain at its minimum
speed until the slide valve loads above the capacity control
“Slide Valve” setpoint. If the slide valve cannot load due to a
slide valve load inhibit condition or because the compressor
cannot build differential pressure, particularly between suc-
tion and oil pressure, the motor speed will increase to meet
the capacity requirement.
When the slide valve reaches the capacity control “Slide
Valve” setpoint, the motor speed can then increase. At this,
point the slide valve and motor speed continue to increase
independently of one another until the capacity requirement
is met or the maximum values are reached. If the compressor
is in “AUTO” mode, the motor speed is controlled by the “VFD
Proportional Band” and “VFD Integration Time” setpoints.
If less capacity is required, the Quantum
™
LX will first de-
crease the motor speed. The motor speed is allowed to
drop as low as the capacity control “Drive Speed” setpoint.
When the motor speed reaches this point, depending on the
Quantum
™
LX’s configuration, the slide valve may unload or
the Quantum
™
LX may stop the compressor. If the slide valve
is permitted to unload, the slide valve will not unload below
the “Variable Speed Minimum Slide Valve Position” setpoint
while the compressor is running.
When the Quantum
™
LX turns off the compressor, the control
panel initially keeps the Vyper
™
in “STANDBY” mode. In this
mode, the drive’s DC Link remains energized so that when
the Quantum
™
LX sends a start command to the Vyper
™
,
the compressor starts immediately. The Quantum
™
LX panel
holds the Vyper
™
in “STANDBY” mode for up to two (2) hours
after the compressor shuts down. If this standby period
passes without the compressor turning on, the Vyper
™
then
switches from Standby to “OFF”.
When the Vyper
™
enters “OFF” mode, the DC Link is de-en-
ergized and the Vyper
™
will have to go through the thirty (30)
second precharge prior to restarting the compressor. The
current Vyper
™
Operating Mode is displayed on the Vyper
™
Status Screen. To allow the compressor to restart quickly, the
control panel’s Recycle Delay is disabled. When controlled by
the Vyper
™
, the compressor can be started multiple times in a
short period of time without causing damage to the motor.
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