Unit Controls
Pressing the COOLING SETPOINTS key a second time will display the remote setpoint and cooling range. This display automatically updates about every 2 seconds. Notice that these setpoints are not “locally” program- mable, but are controlled by a remote device such as an ISN control. These setpoints would only be valid if the unit was operating in the REMOTE mode.
The messages below illustrate both leaving chilled liq- uid control and return chilled liquid control respectively
R E M S E T P = | 4 4 | . | 0 | ° | F |
R A N G E = + | / - 2 | . | 0 | ° | F |
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(leaving chilled liquid control)
R E M S E T P | = | 4 4 | . | 0 | ° | F |
R A N G E | = | 1 0 | . | 0 | ° | F |
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(return chilled liquid control)
The low limit, high limit, and default values for the keys under “SETPOINTS” are listed in Table 28.
Pressing the COOLING SETPOINTS a third time will bring up the display that allows the Maximum EMS- PWM Temperature Reset to be programmed. This message is shown below.
M A X E M S - P W M R E M O T E
T E M P R E S E T = + 2 0 ° F
The Temp Reset value is the maximum allowable reset of the temperature setpoint. The setpoint can be reset upwards by the use of a contact closure on the PWM Temp Reset input (CTB1 terminals 13 - 20)). See the section on Operating Controls for a detailed explana- tion of this feature.
As with the other setpoints, the Up Arrow and Down Arrow keys are used to change the Temp Reset value. After using the UP and DOWN ARROWS to adjust to the desired setpoint, the ENTER/ADV key must be pressed to enter this number into memory.
TABLE 28 – COOLING SETPOINTS PROGRAMMABLE LIMITS AND DEFAULTS
SETPOINT KEY | MODEL | LOW LIMIT | HIGH LIMIT | DEFAULT | |
| WATER COOLING | 40.0°F | **70.0°F | 44.0°F | |
| 4.4°C | 21.1°C | 6.7°C | ||
LEAVING CHILLED LIQUID SETPOINT |
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GLYCOL COOLING | *10.0°F | **70.0°F | 44.0°F | ||
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| 21.1°C | 6.7°C | |||
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LEAVING CHILLED LIQUID | — | 1.5°F | 2.5°F | 2.0°F | |
CONTROL RANGE | 0.8°C | 1.4°C | 1.1°C | ||
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| WATER COOLING | 40.0°F | 70.0°F | 44.0°F | |
RETURNED CHILLED LIQUID SETPOINT |
| 4.4°C | 21.1°C | 6.7°C | |
GLYCOL COOLING | 10.0°F | 70.0°F | 44.0°F | ||
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| 21.1°C | 6.7°C | |||
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RETURN CHILLED LIQUID | — | 4.0°F | 20.0°F | 10.0°F | |
CONTROL RANGE | 2.2°C | 11.1°C | 5.6°C | ||
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MAX | — | 2°F | 40°F | 20°F | |
TEMPERATURE RESET | 1.0°C | 22.0°C | 11.0°C | ||
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*Refer to Engineering Guide for operation below 30°F
*When using glycol, Leaving Chilled Liquid Setpoint should not be set below 20°F
**Do not exceed 55°F (12.8°C) setpoint before contacting the nearest York Office for application guidelines.
76 | YORK INTERNATIONAL |
