FORM
Compressor Staging for Return Water Control –
6 Compressors
Cooling Setpoint = 45° F (7.2° C) Range = 10° F (5.6° C)
TABLE 36 – COMPRESSOR STAGING FOR RETURN WATER CONTROL
# OF COMP ON | 0 | *1+HG | 1 | 2 | 3 | 4 | 5 | 6 | |
RWT | 45°F | 46.25°F | 46.7°F | 48.3°F | 50.0°F | 51.7°F | 53.4°F | 55.0°F | |
(7.2°C) | (7.9°C) | (8.2°C) | (9.1°C) | (10.0°C) | (11.0°C) | (11.9°C) | (12.8°C) | ||
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*Unloading only
TABLE 37 – RETURN CHILLED LIQUID CONTROL FOR 6 COMPRESSORS (8 STEPS)
*STEP | COMPRESSOR ON POINT | COMPRESSOR OFF POINT |
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0 |
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1 |
| SETPOINT |
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2 | SP + CR/6 | SP + CR/8 | SEE NOTE 1 |
3 | SP + 2*CR/6 | SP + CR/6 | SEE NOTE 2 |
4 | SP + 2*CR/6 | SP + CR/6 | SEE NOTE 3 |
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5 | SP + 3*CR/6 | SP + 2*CR/6 |
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6 | SP + 4*CR/6 | SP + 3*CR/6 |
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7 | SP + 5*CR/6 | SP + 4*CR/6 |
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8 | SP + CR | SP + 5*CR/6 |
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2
TABLE 38 – RETURN CHILLED LIQUID CONTROL FOR 4 COMPRESSORS (6 STEPS)
*STEP | COMPRESSOR ON POINT | COMPRESSOR OFF POINT |
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0 |
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1 |
| SETPOINT |
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2 | SP + CR/4 | SP + CR/8 | SEE NOTE 1 |
3 | SP + 2*CR/4 | SP + CR/4 | SEE NOTE 2 |
4 | SP + 2*CR/4 | SP + CR/4 | SEE NOTE 3 |
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5 | SP + 3*CR/4 | SP + 2*CR/4 |
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6 | SP + CR | SP + 3*CR/4 |
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Notes:
1.Step 1 is Hot Gas Bypass and is skipped when loading occurs. Hot Gas Bypass operation is inhibited during Pumpdown.
2.Step 3 is skipped when loading occurs.
3.Step 4 is skipped when unloading occurs.
* STEP can be viewed using the OPER DATA key and scrolling to COOLING DEMAND.
YORK INTERNATIONAL | 89 |
