83
APPENDIX B (cont)
The following tables show the loading sequence for 30HX206
(57/43 split) and 30HX271 (67/33 split) chillers. All compres-
sors have two loaders and the chiller is configured for staged
circuit loading. Loaders A1 on compressors A1 and A2 are en-
ergized in parallel. The same is true for Loaders A2 on both
compressors A1 and A2. See Note 3.
NOTES:
1. Stage 3A is not used by the algorithm when increasing stages. Stage 3 is
not used by the algorithm when decreasing stages.
2. The % Total Capacities above are calculated based on compressor nominal
tons. For the case of the 57/43 split above, the 30HX uses compressors
with flow rates of 209, 123, and 250 cfm (from compressor model numbers
06N_209, 06N_123, and 06N_250), which represent nominal tons of 66,
39, and 80 (respectively) at 60Hz. A factor of 40% is used when no loaders
are energized, and a factor of 70% is used when Loader 1 is energized.
The capacity shown for Stage 4 above is calculated as follows:
% Total Capacity=[(0.70 x 66 + 0.70 x 39 + 0.0 x 80)/(66 + 39 + 80)] x 100%
= 39.7 %
3. The loading sequence fo 30GX205-265 units is the same as those shown
for the 30HX206, 271 above.
STANDARD LOADING SEQUENCE (CIRCUIT A LEAD CIRCUIT, 3-COMPRESSOR UNIT)
STAGE
COMP
A1
LOADER
A1
LOADER
A2
COMP
A2
COMP
B1
LOADER
B1
LOADER
B2
% TOTAL
CAPACITY
(57/43 Split)
% TOTAL
CAPACITY
(67/33 Split)
0
0
0
0
0
0
0
0
0.0
0.0
1
1
0
0
0
0
0
0
14.3
13.3
2
1
1
0
0
0
0
0
25.0
23.3
3
1
1
1
0
0
0
0
35.7
33.3
4
1
1
0
1
0
0
0
39.7
46.7
5
1
1
1
1
0
0
0
56.8
66.7
6
1
1
1
1
1
1
0
87.0
90.0
7
1
1
1
1
1
1
1
100.0
100.0
CLOSE CONTROL LOADING SEQUENCE (CIRCUIT A LEAD CIRCUIT, 3-COMPRESSOR UNIT)
STAGE
COMP
A1
LOADER
A1
LOADER
A2
COMP
A2
COMP
B1
LOADER
B1
LOADER
B2
% TOTAL
CAPACITY
(57/43 Split)
% TOTAL
CAPACITY
(67/33 Split)
0
0
0
0
0
0
0
0
0.0
0.0
1
1
0
0
0
0
0
0
14.3
13.3
2
1
1
0
0
0
0
0
25.0
23.3
3
1
1
1
0
0
0
0
35.7
33.3
3A
1
0
0
1
0
0
0
22.7
26.7
4
1
1
0
1
0
0
0
39.7
46.7
5
1
1
1
1
0
0
0
56.8
66.7
6
1
1
1
1
1
0
0
74.1
80.0
7
1
1
1
1
1
1
0
87.0
90.0
8
1
1
1
1
1
1
1
100.0
100.0
LEGEND
0 — Off
1 — On