YASKAWA iQpump1000 User Manual page 162

4.6 iQpump Presets and Functions
u
Well Draw Down Control Application Preset
The Well draw down function allows the drive to deliver water at a constant pressure as long as ground water level remains
above a specified level. If the ground water level drops to this specified level the drive will switch from a constant pressure
regulator to a level regulator, which will continue to supply water at the recharge rate of the well. Water will continue to flow
at a reduced rate. Should the water level down hole continue to drop the drive will go to sleep and wait till the water level rises
again to the specified wake up level to start pumping again. Once the water level rises above that level it will switch back to
constant pressure mode.
n Start Up Procedure
The following is a sample setup for the Well Draw Down function with 4 to 20 mA transducer feedback on both level (connected
to input A1) and constant pressure (connected to A2)
1.
Select a Proper Depth Sensing Transducer. The proper transducer for depth sensing has been specifically designed
for depth sensing. This means the transducer element, electrical connections, and connecting cable are sealed for
submersion. Additionally the sensor will have a vent tube running the length of the electrical conductors to compensate
for changes in barometric air pressure, which ensures accurate feedback with changing weather patterns. Another
important design characteristic is that the electrical conductors are installed by the manufacturer at the length specified
by the installer. This ensures that the manufacturer can calibrate the transducer to compensate for the voltage drop
across the conductor length. The maximum length for pressure transducer leads is 50 meters (164 feet) and beyond
that length the voltage drop will cause inaccurate feedback. It is common for wells to exceed this depth. Do not use
standard pressure transducer for level control. Select a range of depth that closely matches your application range.
One size does not fit all as depth calculations work with small changes in feedback. If the range is too large accuracy
will be compromised.
Proper Depth Transducer Characteristics:
Sealed element and electrical connections
Barometric compensation
Specified cable length calibrated by the manufacturer
Proper range, one that is close to applications actual operation
2.
Install Depth Sensing Pressure Transducer Down Hole. Since the feedback from the transducer is low voltage and
the output of the drive to the motor is a PWM waveform an effort should be made to keep the transducer leads as far
from the motor leads as possible. Given that space in the bore hole is at a premium this is a difficult task and connection
of the transducer shield drain wire is important. Many installers will set the transducer in its own plastic tubing with a
cap at the bottom end that the transducer can rest on. It is necessary to drill holes in the tubing at or close to the
bottom to allow water to flood the tube. This type of installation will help protect the transducer and connecting cable
from damage and allow it to be retrieved if necessary.
3.
Connect Level Transducer to the drive via Terminal A1. Most depth level transducers are current based feedback,
typically 4 to 20 mA. The A1 terminal of the drive is selectable for either voltage or current based pressure transducer
feedback. Most transducers in common use are current based (4 to 20 mA).
4.
Set the drive to accept current based (4 to 20 mA) Feedback Set the A1 terminal of Jumper S1 to current type input
(I) as shown in Figure
function of the A1 input, Well Level feedback
Setting
V (top position)
I (bottom position)
5.
Connect Standard Pressure Transducer to Terminal A2. Terminal A2 is designed to accept both current and voltage
based feedback devices and by default the drive is set to 4 to 20 mA input. Make sure to set all necessary parameters
for proper constant pressure regulation.
162
4.12. Set parameter H3-01 to 2 (4 to 20 mA) for signal type on A1. Set parameter H3-02 to 23,
Figure 4.12 Terminal A1 Set to Current Input
Table 4.6 Jumper S1 Settings
Jumper S1
V
I
A1 A2 A3
Description
Voltage input (0 to 10 V Bipolar)
Current input (4 to 20 mA or 0 to 20 mA)
YASKAWA TOEP YAIP1W 01F YASKAWA AC Drive - iQpump1000 User Manual