FORM 150.40-NM20
57
YORK INTERNATIONAL
(YCHA120, 150, 175 & 200)
OPTIONAL LOADING/UNLOADING
(LEAVING WATER TEMPERATURE (LWT)
CONTROL)
Optional loading and unloading of cylinders can be
accomplished in response to leaving chilled water tem-
perature as sensed by the Micro Logic Board.
It is advisable, to assure that cycling problems do not
occur, to use LWT Control only if 8 stages of loading
and unloading is present on the chiller. In addition, 8
stage control from the Micro Logic Board is initiated by
placing J8 IN or Sw. 5 ON. Note: J8 should only be IN
or Sw.5 ON if the chiller is equipped with 6 or 8 stages.
LWT Control is selected by placing J10 IN or Sw. 3 ON
on the Micro Logic Board. Various cooling ranges can
then be selected depending upon the allowable devia-
tion from setpoint.
Control Ranges can be selected on the front panel with
the Cooling Range Rotary Switch. The Cooling Range
Codes and their respective cooling ranges are listed
above right for optional LWT Control. Note: ON LWT
Control, the cooling ranges on the Control Panel are no
longer meaningful.
CAUTION: Selection of the Cooling Range should be
made according to the deviation from
setpoint which can be tolerated and whether
more than normal system cycling of the
loaders and compressors is experienced
due to a cooling range which is too tight.
Pages 57-59 show a listing of each cooling range code
along with the temperatures at which each stage loads
and unloads.
Code
Range
0
+ 1.0°F
1
+ 1.2°F
2
+ 1.4°F
3
+ 1.5°F
4
+ 1.6°F
5
+ 1.8°F
6
+ 1.9°F
7
+ 2.0°F
LWT COOLING RANGES (6 AND 8 STAGE)
If the LWT option is utilized, loading and unloading for
each stage and the respective temperature at which it
occurs is shown in the tables on pages 57-59. A table is
provided for each of the Cooling Range Codes 0-7.
*
If optional 6 stage loading/unloading is included, stage 4 loading and unloading is not included on either compressor. Therefore, in the
examples above, no system response will take place at the temperatures where stage 4 is to be activated or deactivated.
STAGE
ON
OFF
Lag Compr. Loader Stage 4*
Setpoint plus 1.0°F
Setpoint plus 0.4°F
COOLING RANGE
Lag Compr. Loader Stage 3
Setpoint plus 0.8°F
Setpoint plus 0.2°F
SWITCH = 0
Lag Compr. Loader Stage 2
Setpoint plus 0.6°F
Setpoint
Lag Compressor Stage 1
Setpoint plus 0.4°F
Setpoint minus 0.2°F
COOLING RANGE
Lead Compr. Loader Stage 4*
Setpoint plus 0.2°F
Setpoint minus 0.4°F
OF +1°F
Lead Compr. Loader Stage 3
Setpoint
Setpoint minus 0.6°F
Lead Compr. Loader Stage 2
Setpoint minus 0.2°F
Setpoint minus 0.8°F
Lead Compressor Stage 1
Setpoint minus 0.6°F
Setpoint minus 1.0°F
STAGE
ON
OFF
Lag Compr. Loader Stage 4*
Setpoint plus 1.2°F
Setpoint plus 0.9°F
COOLING RANGE
Lag Compr. Loader Stage 3
Setpoint plus 1.0°F
Setpoint plus 0.7°F
SWITCH = 1
Lag Compr. Loader Stage 2
Setpoint plus 0.8°F
Setpoint plus 0.5°F
Lag Compressor Stage 1
Setpoint plus 0.5°F
Setpoint plus 0.2°F
COOLING RANGE
Lead Compr. Loader Stage 4*
Setpoint plus 0.3°F
Setpoint
OF +1.2°F
Lead Compr. Loader Stage 3
Setpoint
Setpoint minus 0.4°F
Lead Compr. Loader Stage 2
Setpoint minus 0.3°F
Setpoint minus 0.8°F
Lead Compressor Stage 1
Setpoint minus 0.6°F
Setpoint minus 1.2°F
Summary of Contents for YCAQ10
Page 20: ...YORK INTERNATIONAL 20 LD01779 YCHA100 FIG 9 WIRING DIAGRAM YCHA100...
Page 21: ...FORM 150 40 NM20 21 YORK INTERNATIONAL YCHA100 LD01779 D...
Page 22: ...YORK INTERNATIONAL 22 LD01780 L YCHA100 FIG 9 Continued...
Page 23: ...FORM 150 40 NM20 23 YORK INTERNATIONAL LD01780 R YCHA100...
Page 24: ...YORK INTERNATIONAL 24 YCHA100 LD01781 FIG 9 Continued...
Page 25: ...FORM 150 40 NM20 25 YORK INTERNATIONAL LD01782 YCHA100...
Page 46: ...YORK INTERNATIONAL 46 LD01787...
Page 47: ...FORM 150 40 NM20 47 YORK INTERNATIONAL LD01788...
Page 48: ...YORK INTERNATIONAL 48 LD01789...
Page 49: ...FORM 150 40 NM20 49 YORK INTERNATIONAL LD01790...
Page 50: ...YORK INTERNATIONAL 50 LD01791...
Page 51: ...FORM 150 40 NM20 51 YORK INTERNATIONAL LD01792...
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