The input/output “ChcaaComm” is a communication signal between chiller modules to calculate the average cooling power of active chillers. One of the chillers calculates the average cooling power capacity and the parameter SYS-02 of this chiller must be set to value “1”. All the other parameters of this chiller must be set to the value SYS-02 = 0.
Example:
In an application with three chillers, the first one works at 70% of its capacity, the second one at 60% and the third one at 0%. The third chiller has the parameter setting SYS-02 = 1.
The first chiller reads the input „XFMChcaaCom“ = 0 and writes the value 7001. The second chiller will write the value 13002 and the third chiller does not change the value. The average capacity will be calculated by the third module and displayed at the output „DispAvgCap = 130 / 3 = 43,3 of this module.
Fig. 2. Example
Table 7. DispAvgCap calculation
sender |
CAA |
Comments |
receiver |
||
Format [CCCCNN] |
CCCC = sum of cooling powers of all active chiller stages NN = total number of active chillers |
Communication between CAA-modules. The result is displayed at the input/ output DispAvgCap |
Table 8. Parameter List
Description |
Value Range |
Default Value |
Unit |
SYS-02: communication signal chiller power 0 = transmit the power 1 = calculate the average power |
0...1 |
0 |