Step Control; Vfd Settings - Emerson Vilter Vission 20/20 Operation And Service Manual

Section 26 • Remote Oil Cooler
Manual
• Mode for controlling Remote Oil Cooler operation
manually. Operator controls the operation by manual
stepping using an on/off toggle button at each step.
Remote Oil Cooler Temperature:
• This is the read only parameter and it displays the
present value of Remote Oil Cooler Temperature.
Remote Oil Cooler Temperature is mapped on Analog
Auxiliary Input #5.
Remote Oil Cooler Temperature Setpoint:
• This is the Remote Oil Cooler Temperature setpoint
that needs to be maintained.
Upper Deadband:
• This is the Remote Oil Cooler Temperature setpoint
upper deadband value.
Lower Deadband:
• This is the Remote Oil Cooler Temperature setpoint
lower deadband value.
High to Low Speed Fan Delay:
• This is time delay for fan spin down in case of 2 speed
motor/dual speed fan.

Step Control

The Step Control allows the operator to setup the man-
ner in which Fans, Pumps & VFD will be turned on/off.
Fans & Pumps are connected on digital outputs Out #1
to Out #4. VFD Fan is connected on Analog Output. Each
step can have maximum of fi ve outputs connected to it.
Each step can be opted in or out depending on enabling
of checkbox.
When Run Mode is Auto and Remote Oil Cooler
Temperature rises above upper deadband, Remote Oil
Cooler step gets incremented from Step 1 to Step 5 and
hence switching on/off Pumps, Fans & VFD connected on
outputs. This holds true for decrementing of steps from
Step 5 to Step 1 when Remote Oil Cooler Temperature
falls below lower deadband.
Step Delay:
• Allows operator to set time delays between Remote
Oil Cooler steps. Remote Oil Cooler Temperature
must be outside upper or lower deadband continu-
ously for delay time in order to increase or decrease
Remote Oil Cooler steps. While in a VFD step, an ad-
ditional step can only be added once VFD has reached
its maximum speed setpoint and the delay timers are
satisfi ed. Similarly in a VFD step, a step can only be
removed once VFD has reached its minimum speed
26 – 2
setpoint and the delay timers are satisfi ed. Step Delay
acts as "ON" timer while loading and acts as "OFF"
timer while unloading for the same step.
Low Speed Fan:
• Allows steps to have option for time delay in case of
fan spin down. Any of Out #1 to Out #4 can be se-
lected as Low Speed Fan through combobox. E.g.:
Let's say Out #2 is selected as Low Speed Fan in Step
2. When step 2 becomes active during Remote Oil
Cooler operation which is after Step 2 timeout de-
lay, Out #2 is left off for time as set by the operator
in High to Low Speed Delay. After low speed fan ener-
gizes, then timer for Step 3 starts timing.
Control:
• Toggle any of the steps On/Off during Manual opera-
tion of Remote Oil Cooler. This button is active only
when Run Mode selected is Manual. During Auto op-
eration of Remote Oil Cooler Control, control button
for active step will be "ON".

VFD Settings

This page is active only when Remote Oil Cooler VFD is
selected in Confi guration Screen, see Section 19. For
Remote Oil Cooler VFD Screen, see Figure 26-2. When a
VFD fan is used for the remote oil cooler oil cooling, the
speed of the VFD is controlled using PID algorithm.
P = Proportional (gain):
• Used to adjust the fan speed action in direct propor-
tion to the difference between the control setpoint
and the process variable (SP - PV = error). The pro-
portional term is a unit less quantity and is used for
coarse adjustment. This setpoint should be set to the
lowest value that gives adequate control system re-
sponse. Increasing the proportional setting increases
the control system's sensitivity to small process fl uc-
tuations and the tendency to hunt.
I = Integral (reset):
• Used to adjust the capacity control action, integrat-
ing the error over time, to account for a small error
that has persisted for a long time. This quantity is
used for fi ne adjustment. This setpoint is used to
smooth out process variations. This setpoint should
be set high enough to prevent hunting but not too
high or it will cause control system overshoot.
D = Derivative (rate):
• Used to adjust the capacity control action, account-
ing for how fast the error is changing, positively or
negatively.
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.9