Fuji Electric FRENIC-AQUA series, User Manual

Page: 527 / 751

6-246
Function code Name Data Description
E01 to E07 [X1] to [X7] 151 to 158: MEM1 to
MEM8
Pump control motor 1
to 8
These function codes individually separate
pumps from the inverter drive motor fixed
system with external signals.
Only pumps whose
MEM signals are ON are
subject to this system.
J465 Auxiliary motor
(Frequency
operation level)
OFF, 0.1 to 120 Hz
J466 Auxiliary motor
(Hysteresis
width)
0.0 to 120 Hz
When all pumps subject to this system are
operating and the inverter output exceeds the
setting of J465, the auxiliary pump start signal
comes ON.
If the inverter decelerates from the setting of
J465 by the setting of J466, the auxiliary pump
start signal goes OFF.
Each function code is detailed separately.
Cascade control (Inverter drive motor floating system)
To switch a maximum of four pumps between inverter drive and commercial power drive by a single
FRENIC-AQUA, configure two magnetic contactors per pump.
The FRENIC-AQUA drives the first pump at variable speed under PID control. If the frequency rises
due to a PV signal level drop to satisfy the pump adding conditions, the FRENIC-AQUA switches the
inverter-driven pump to commercial power drive and drives the newly added pump. After starting all
pumps, the inverter can further drive a single auxiliary pump (MA). If the PV signal level rises and the
frequency of the inverter-driven pump drops to satisfy the pump subtracting conditions, the
FRENIC-AQUA cancels start signals of the pumps being driven by commercial power, thereby
stopping them successively. At the time of decreasing pumps, the FRENIC-AQUA continues to drive
the last added pump.
In this system, each of pumps to be controlled requires two signal lines for inverter drive and
commercial power drive. To operate the pump drive system in a maximum configuration, an auxiliary
pump start signal line is further required.
The number of start signal lines available on the FRENIC-AQUA is a total of six--four transistor
output lines and two relay output lines in a standard configuration, so the FRENIC-AQUA can control
a total of three pumps in a standard configuration.
To operate the pump drive system using four or more pumps, it is necessary to add the optional relay
output card (OPC-RY2) to the FRENIC-AQUA. It can add seven relay output lines.
The advantage of this system is that the operating times of pumps can be averaged since the
FRENIC-AQUA cycles through pump motors.
Cascade control (Inverter drive motor fixed + commercial power-driven motor system)
This system is the same as the inverter drive motor floating system in the basic configuration, except
that it fixes the inverter drive pump according to the slow flowrate unit and switches the inverter drive
pump when the system is started at the next time.
The advantage of this system is that the ON/OFF times of the magnetic contactors can be reduced.
Therefore, this system is suitable for clean water supply systems repeating slow flowrate stops
frequently.