Eaton Cutler-Hammer SLX9000 Series, User Manual

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SLX9000 Adjustable Frequency Drives User Manual
9-40
For more information visit: www.eaton.com MN04003020E
January 2009
Pump and Fan Control
The Pump and Fan Control can be used to control one variable speed drive and up to three
auxiliary drives. The PID controller of the drive controls the speed of the variable speed drive
and gives control signals to start and stop the auxiliary drives to control the total flow. In
addition to the eight parameter groups provided as standard, a parameter group for multi-
pump and fan control functions is available.
Pump and Fan Control is used to control the operation of pumps and fans. The application
utilizes external contactors for switching between the motors connected to the drive. The
autochange feature provides the capability of changing the starting order of the auxiliary
drives.
Short Description of PFC Function and Essential Parameters
Automatic Changing Between Drives (Autochange & Interlockings Selection, P2.10.4/
ID1027)
The automatic change of starting and stopping order is activated and applied to either the
auxiliary drives only or the auxiliary drives and the drive controlled by the frequency
converter depending on the setting of parameter 2.10.4.
The Autochange function allows the starting and stopping order of drives controlled by the
pump and fan automatics to be changed at desired intervals. The drive controlled by
frequency converter can also be included in the automatic changing and locking sequence
(par 2.10.4). The Autochange function makes it possible to equalize the run times of the
motors and to prevent, for example, pump stalls due to running breaks that are too long.
●
Apply the Autochange function with parameter 2.10.4, Autochange.
●
The autochange takes place when the time set with parameter 2.10.5 Autochange
interval has expired and the capacity used is below the level defined with parameter
2.10.7, Autochange frequency limit.
●
The running drives are stopped and re-started according to the new order.
●
External contactors controlled through the relay outputs of the frequency converter
connect the drives to the frequency converter or to the mains. If the motor controlled
by the frequency converter is included in the autochange sequence, it is always
controlled through the relay output activated first. The other relays activated later
control the auxiliary drives.
This parameter is used to activate the interlock inputs (Values 3 & 4). The interlocking signals
come from the motor switches. The signals (functions) are connected to digital inputs which
are programmed as interlock inputs using the corresponding parameters. The pump and fan
control automatics only control the motors with active interlock data.
●
If the interlock of an auxiliary drive is inactivated and another unused auxiliary drive
available, the latter will be put to use without stopping the frequency converter.
●
If the interlock of the controlled drive is inactivated, all motors will be stopped and re-
started with the new set-up.
●
If the interlock is re-activated in Run status, the automatics will stop all motors
immediately and re-start with a new setup. Example: [P1
→
P3]
→
[P2 LOCKED]
→
[STOP]
→
[P1
→
P2
→
P3]
See Page 9-41 , Examples.