Firmware Manual

9000X AF Drives
MN04004001E
For more information visit: www.eaton.com
7-5
August 2010
Pump and Fan Control Application
Short Description of Function and Essential Parameters
Automatic Changing Between Drives (Autochange, P1.9.24)
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. 1.9.25). The Autochange function makes it possible to equalize the run times of the
motors and to prevent e.g. pump stalls due to too long running breaks.
● Apply the Autochange function with parameter 1.9.24, Autochange.
● The autochange takes place when the time set with parameter 1.9.26, Autochange
interval, has expired and the capacity used is below the level defined with parameter
1.9.28, 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 (see Figure 7-4 and Figure 7-5).
Parameter 1.9.24 — Autochange
0 Autochange not used
1 Autochange used
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 1.9.25, Automatics selection. By default,
the Autochange is activated for 2 drives. See Figure 7-1 and Figure 7-4.
Parameter 1.9.25 — Autochange/Interlockings Automatics Selection
0 Automatics (autochange/interlockings) applied to auxiliary drives only
The drive controlled by the frequency converter remains the same. Therefore, mains
contactor is needed for one auxiliary drive only.
1 All drives included in the autochange/interlockings sequence
The drive controlled by the frequency converter is included in the automatics and a contactor
is needed for each drive to connect it to either the mains or the frequency converter.
Parameter 1.9.26 — Autochange interval
After the expiry of the time defined with this parameter, the autochange function takes place
if the capacity used lies below the level defined with parameters 1.9.28 (Autochange frequency
limit) and 1.9.27 (Maximum number of auxiliary drives). Should the capacity exceed the
value of P1.9.28, the autochange will not take place before the capacity goes below this limit.
● The time count is activated only if the Start/Stop request is active at control place A.
● The time count is reset after the autochange has taken place or on removal of Start
request at control place A.