Carrier Ecologic Series 3 - (Capacity Loading Sequence); Appendix B

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APPENDIX B
Capacity Loading Sequence Example —
The fol-
lowing tables show the loading sequence for a 30HX186
(50/50 split) and a 30HX161 (59/41 split) chiller. Each
compressor has 2 loaders. There is no difference in operation
between “Staged” and “Equal” circuit loading on 2 compressor
chillers.
NOTES:
1. Stage 3A (and 3B for 59/41 split) is not used by the algorithm when increas-
ing stages. Stage 3 (and 2 for a 59/41 split) is not used when decreasing
stages.
2. The % Total Capacities above are calculated based on compressor nominal
tons. For the case of the 59/41 split above, the 30HX uses compressors
with flow rates of 250 and 174 cfm (from compressor model numbers
06N__250 and 06N__174), which represent nominal tons of 80 and 56
(respectively) at 60Hz. A factor of 40% is used when no loaders are ener-
gized, and a factor of 70% is used when Loader 1 is energized. The capac-
ity shown for Stage 3B above is calculated as follows:
% Total Capacity=[(0.40 x 80 + 0.70 x 56)/(80 + 56)] x 100%
=52.4 %
STANDARD LOADING SEQUENCE (CIRCUIT A LEAD CIRCUIT, 2-COMPRESSOR UNIT)
STAGE
COMP
A1
LOADER
A1
LOADER
A2
COMP
B1
LOADER
B1
LOADER
B2
% TOTAL
CAPACITY
(50/50 Split)
% TOTAL
CAPACITY
(59/41 Split)
0 00 000 0 0.0 0.0
110 000 0 20.0 23.5
211 000 0 35.0 41.1
311 100 0 50.0 58.8
411 011 0 70.0 70.0
511 011 1 85.0 82.4
61 1 1 1 1 1 100.0 100.0
CLOSE CONTROL LOADING SEQUENCE (CIRCUIT A LEAD CIRCUIT, 2-COMPRESSOR UNIT)
STAGE
COMP
A1
LOADER
A1
LOADER
A2
COMP
B1
LOADER
B1
LOADER
B2
% TOTAL
CAPACITY
(50/50 Split)
% TOTAL
CAPACITY
(59/41 Split)
0 00 000 0 0.0 0.0
110 000 0 20.0 23.5
211 000 0 35.0 41.1
311 100 0 50.0 58.8
3A 10 010 0 40.0 40.0
3B 10 011 0 55.0 52.4
410 011 1 70.0 64.7
511 011 1 85.0 82.4
61 1 1 1 1 1 100.0 100.0
LEGEND
0 —Off
1—On
Nominal Tons
COMPRESSOR
PART NO.
60 Hz NOM.
TONS
50 Hz NOM.
TONS
06N__123 39 —
06N__146 46 39
06N__174 56 46
06N__209 66 56
06N__250 80 66
06N__300 —80