Franklin Electric CERUS X-DRIVE CXD-003A-4V, Installation And Operation Manual

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OPERATION
Control Options
74
Frequency Limits Controlled by Water (Analog) Level
This feature changes VFD or PID high frequency limit value (whichever is set as Auto Speed Reference)
based on an Aux Input value. It can be used to limit pump speed in a constant pressure system by well or
tank water level to help prevent over-pumping the source. It requires an additional transducer (level or pres
-
sure) installed in the well or tank.
To enable this feature, set the following parameters:
AUX AI Select [ADV2–58]: Select the analog input ( AVI1, AVI2, ACI ) with the level transducer connection. Set
unit type and scaling in
[ADV2-59]
to
[ADV2-61]
.
NOTE: It is recommended to use 4-20mA (less sensitive to electrical noise) level transducer.
Limit by Level [IO–16]: This parameter enables Limit by Level feature. If Enabled, the VFD will monitor the
analog input set as Auto mode speed reference or PID feedback source and decrease High Frequency Limit
value.
Max Limit Level [IO–17]: This parameter sets the maximum value (in Aux Input units) for VFD or PID High
Frequency Limit control range. At signal above this value the VFD will use original VFD or PID High Fre -
quency limit value.
Min Limit Level [IO–18]: This parameter sets the minimum value of Aux Analog input corresponding to
Min Freq Limit [IO-19] . If AUX input signal is below this value, VFD will use [IO-19] value as VFD or PID High Fre -
quency value.
Min Freq Limit [IO–19]: This parameter sets Minimum value for High Frequency Limiting range correspond -
ing to
Min Limit Level [IO-18]
.
NOTE: VFD will show Limit by Level message when High Freq Limit is decreased by this feature.
For example: The diagram shows how pump speed might be limited
by well or tank water level transducer signal.
In this example, a 4-20mA water level transducer is connected to an
auxiliary input and selected in
[ADV2-58]
. Transducer range is scaled to
16 feet. Limit by Level feature settings are [IO-17] at 10 feet (14mA),
[IO-18]
at 4 feet (8mA), and
[IO-19]
at 40Hz.
PID Low Freq Limit [SET–22]
is
30Hz and PID High Freq Limit [SET-23] is 55Hz.
When water level stays at or above 10 feet, VFD will maintain pressure
with a frequency range from 30 Hz to 55 Hz. When water level drops
below 10 feet, the VFD or PID High Frequency limit will be decreased
linearly from 55 Hz at 10 feet to 40 Hz at 4 feet water level. If water
level drops below 4 feet, the frequency limit stays at 40Hz and drive
will operate in the range from 30 to 40 Hz.
[IO-17]
[IO-18]
Water Level
20mA
16 ft
(4.9 m)
10 ft
(3.05 m)
4 ft
(1.22 m)
14mA
8mA
4mA
Aux
Input
0Hz 30Hz 40Hz 55Hz
Speed Control Zone
Freq