S&C Instruction Sheet 1022-540 13
Current Control Mode (IntelliCap with Var only)
When
Automatic
mode is enabled and the control is in
Current
mode, the control switches
the bank based on measured single-phase current flow and uses the following logic to
determine when to switch the bank:
(a) The control monitors single-phase line current.
(b) When the control senses the current has passed the
Single-Phase Current at
Which Bank Switches In
or
Single-Phase Current at Which Bank Switches
Out
setpoint, it starts the
Current Change Time Threshold
timer.
(c) When the single-phase current remains continuously above the
Single-Phase
Current at Which Bank Switches In
setpoint for the duration of the timer, the
control switches the bank in. When single-phase current remains continuously
below the
Single-Phase Current at Which Bank Switches Out
setpoint for the
duration of the timer, the control switches the bank out.
Note:
Voltage must remain in a range where switching the capacitor bank will not cause a
voltage-override condition.
Var Control Mode (IntelliCap with Var only)
When
Automatic
mode is enabled and the control is in
Var
mode, the control switches the
bank based on calculated 3-phase kvars (kilovoltamperes, reactive). The control uses the
following logic to determine when to switch the bank:
(a) The control monitors 3-phase kvar level.
(b) When the control senses the kvar level has passed the
3-Phase kvars at Which
Bank Switches In
or
3-Phase kvars at Which Bank Switches Out
setpoint, it
starts the
Var Change Time Threshold
timer.
(c) If the 3-phase kvar level remains continuously above the
3-Phase kvars at Which
Bank Switches In
setpoint for the duration of the timer, the control switches the
bank in. If the single-phase kvar level remains continuously below the
3-Phase
kvars at Which Bank Switches Out
setpoint for the duration of the timer, the
control switches the bank out.
Note:
Voltage must remain in a range where switching the capacitor bank will not cause a
Voltage-Override
condition.
Current Sensor Location and Reverse Current Flow
For the IntelliCap with Var control, the preferred location of the current sensor is on the
source side of the capacitor bank. The sensor can then measure the effect of the bank when
it is online. However, the control can still account for the effect of the bank when the sensor
is on the load side. This is particularly useful when abnormal circuit switching reverses the
direction of power flow, flipping the relative position of the sensor.
The control switches the bank based on the
Adjusted 3-Phase kvars
setpoint on the
Setup>Site-Related
and
Operation
screens. See Instruction Sheet 1022-530, “IntelliCap
®
Capacitor Control:
Setup
” for more information.
IntelliCap Control Operation
