Multiple Compressor Application - Emerson Copeland Stream Digital 4MFD-13X Application Manuallines

2.6.12 Multiple compressor application

To ensure smooth and continuous modulation, ie, for optimum suction pressure control, the
selection of the Stream Digital and Stream fixed-capacity compressors should be made
according to the following rule:
- F1 < D
- F2 < D+F1
- F3 < D+F1+F2
- ......
- FN < D+F1+F2+....FN-1
Where D = Capacity of the Stream Digital compressor and F1 --- FN = Capacity of the Stream
compressors.
The Stream Digital compressor selected should have the smallest capacity to cover all the gaps
between steps to ensure the most efficient system control.
For example, a 4M*D has a continuous capacity from 50 to 100%. Therefore, when a 4M*D
Stream Digital compressor is selected, the associated fixed-capacity compressor should have 50
to 100% of the full load of the Stream Digital compressor.
NOTE: For best results, the Stream Digital compressor must be the lead compressor. It
must be the first compressor "On" and the last compressor "Off" in multiple compressor
applications.
C6.3.2/0416-0716/E 9