Dunham-Bush HRSC - D, Operating & Maintenance Instructions

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8
UNIT OPERATING LIMITATIONS
1. Maximum allowable cooler water pressure is 200 PSIG.
2. Maximum allowable operating water temperature to cooler is 85°F.
3. Minimum allowable water temperature from cooler is 42°F. If lower temperatures are required, a glycol
solution must be used.
4. Unit should not be installed where it may be subjected to freezing temperatures. Provisions should be
made to maintain the ambient air temperature at least 37°F, to avoid possible damage from freezing.
5. Line voltage should not vary more than the voltage tolerances listed for the unit. Refer to the Electrical
Data table.
SAFETY CONTROLS
The unit is protected by the following safety controls.
1. High Pressure (HP)
2. Low Pressure (LP)
3. High Discharge Temperature (OS)
4. Compressor Solid State Module (CSTM)
5. Low Water Temperature (T2)
6. Phase Loss Monitor (PLM)
7. Control Circuit Breaker (CB1)
If any of these devices should open due to abnormal conditions, the compressor(s) automatically stop. All
controls must be manually reset, except the phase loss monitor (PLM).
HRSC CONTROL SETTINGS
High Pressure Control HP 1-4 Cut-Out 365 PSIG
(Manual Reset)
Low Pressure Control
LP 1-4 Cut-In 55 PSIG
(Auto Reset) Cut-Out 35 PSIG
Low Pressure Freeze Control LPF 1-4 Cut-Out 54 PSIG
PRESSURE ACTUATED LEGEND FACTORY SETTING
PRESSURE ACTUATED LEGEND FACTORY SETTING
Low Chilled Water Temperature Thermostat
(Manual Reset)
T2 Cut-Out 37°F
il Temperature Safety Control
(Adjustable)
OTS 1-4 Cut-Out 240°F
Manual Reset
W7100 Controller Settings
T1 Control Point Set at 44°F
Note: For special units supplied with the NC25-4 microcomputer controller, refer to the “Operations Guide” Form
6874.