In multiple cooling tower applications, it is possible to start a backup fan in another cooling tower when no backup fan exists in the same cooling tower where the alarm occurs. The group feedback of the cooling tower must be connected to the status input of the cooling tower 1/2 control, see figure below.
Fig. 12. Group feedback signal
This example requires that all 3 sequencer modules must be located in the same controller, because the group feedback signal sends values which have to be transferred in the same cycle via a connection or datapoint.
To use this operation mode, in “cooling tower 1/2 control” set the parameter SYS-01 = 1, the ALM-01 and ALM-02 parameters to 0. Use only POS-01 and POS-02 and set POS-03 to 0, POS-13 to 2 and SEQ-05 to 3.
Table 12. Parameter List
Description |
Value Range |
Default Value |
Unit |
SYS-01: use group feedback signal 0 = do not use 1 = use |
0/ 1 |
0 |
- |