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Motor characteristics:
The characteristics of the motor connected to the inverter should be entered into the inverter’s option
parameter list as follows:
•
Motor nominal voltage, power, current and frequency (see motor plate)
•
Motor current and temperature limits
•
U/F ratio. Use the ‘SQUARED’ option for fans and pumps.
•
Motor slip ratio
Setting up the Nexus PPC5000 fuel air ratio control system for use with a inverter drive
In order to use an inverter drive with a 4-20mA interface, an isolated drive board must be installed in
one of the option slots. The following steps must then be taken:
•
Enter option set mode.
•
Map a drive (e.g. air damper 2) to the required inverter output using option parameters 05.X, or
06.X, and setup the control characteristics using options 22.X. See section 8 for details.
•
Enter commission mode.
•
Look at the display for the drive mapped to the inverter output (e.g. air damper 2). The display
should show 0 for a feedback signal of 4mA and 999 for a feedback signal of 20mA. If the dis-
play is flashing ‘LO’, the feedback signal is less than 3.5mA or the polarity of the wiring is
reversed. If the display is flashing ‘HI’, the feedback signal is more than 21.0mA or the polarity
of the wiring is reversed. In both these cases, check the wiring and/or the option parameters on
the inverter.
•
If problems are encountered monitor the reference signal from the Nexus PPC5000 fuel air ratio
control system. With the inverter drive selected, the UP key should increase the current gradu-
ally up to 20mA and the DOWN key should decrease the current gradually down to 4mA.
•
For the rest of the commissioning procedure, treat the inverter drive in the same way as a motor.
The inverter drive has a closed position (4mA), a purge position (20mA), an ignition position
and up to 20 profile positions.
