85
The chiller will monitor the condenser pressure and may turn on the condenser pump
If the condenser pressure is greater than or equal to the COND PRESS OVERRIDE, and the entering
condenser water temperature is less than 115 ° F (46.1 ° C), the condenser pump will energize to try to
decrease the pressure and alert 157 will be generated. The pump will turn off when the condenser
pressure is 3.5 psi (24.1 kPa) less than the pressure override and the condenser refrigerant
temperature) is less than or equal to the entering condenser water temperature plus 3^ F (1.7^ C).
Note: COND PRESS OVERRIDE is in the CONFIGURATION MENU/ PROTECTIVE LIMIT CONFIG
screen. The default value is 140 psig (965 kPa) for 185PSI condenser and 250 psig (1724 kPa) for
300PSI condenser; default value is 10 psig (137.9kPa) for 19DV 44PSI condenser and 55 psig (379.2
kPa) for 19DV 72PSI condenser.
Condenser Freeze Prevention — This control helps prevent condenser tube freeze-up by energizing
the condenser pump relay. The 19 Series Carrier® SmartVu
TM
controls the pump and, by starting it,
helps to prevent the water in the condenser from freezing.
When the chiller is off and condenser saturated refrigerant temperature is less than or equal to the
condenser freeze point, the condenser water pump will be energized (Alarm State 262, PROTECTIVE
LIMIT - CONDENSER FREEZE). The fault state will clear and the pump will turn off when the condenser
saturated refrigerant temperature is more than 5^ F (2.7^ C) above the condenser freeze point and the
entering condenser water temperature is greater than the condenser freeze point. If the chiller is in
recycle shutdown Mode when the condition occurs, the controls will transition to a non-recycle shutdown.
5.19. Quick Test
This function is used to test all controlled outputs except compressor output. The test function will only
be allowed to run when the unit is Off.
User password is required to active this test function. All quick test parameters shall be accessible in the
table “QCK_TEST”. To perform the control test function, the first item “Quick Test Enable” in the
“QCK_TST” table shall be set to enable. The “Quick Test Enable” item will be automatically disabled in
one hour in order to make the controls go back to normal if someone forget to disable it.
Unless otherwise noted, all protective limits shall remain active during Controls Test.
5.19.1. Discrete Outputs
When quick test is enabled, the following discrete outputs can be enabled to be forced to ON by setting
the according points to Yes in the quick test table.
Guide Vane Increase, Guide Vane Decrease, Oil Pump Relay, Oil Heater Relay, EC Valve Open, EC
Valve Close, Economizer Damper Valve Open, Economizer Damper Valve Close, Alarm relay, Alert
relay and Refrigerant Pump relay.
Note: the following outputs cannot be force to ON at the same time
Guide Vane Increase and Guide Vane Decrease;
EC Valve Open and EC Valve Close;
Economizer Damper Valve Open and Economizer Damper Valve Close
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