Auto. Restart After Power Failure; Water/Brine Reset - Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual
19xrv pic iii control
hermetic centrifugal liquid
chillers
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Also See for 19XRV:
- Operation, maintenance and installation manual (200 pages) ,
- Start-up, operation and maintenance instructions manual (160 pages) ,
- Installation instructions manual (76 pages)
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TOWER FAN RELAY LOW is turned on whenever the
condenser water pump is running, flow is verified, and the
difference between cooler and condenser pressure is more
than 07 kPa for entering condenser water temperature
greater than 18.3°C.
TOWER FAN RELAY LOW is turned off when the con-
denser pump is off, flow is stopped, or the EVAP REFRI-
GERANT TEMP is less than the EVAP REF OVERRIDE
TEMP for ENTERING CONDENSER WATER tempe-
rature less than 16.7°C, or the difference between the CON-
DENSER PRESSURE and EVAPORATOR PRESSURE
is less than 17.4 kPa for ENTERING CONDENSER
WATER less than 7°C.
TOWER FAN RELAY HIGH is turned on whenever the
condenser water pump is running, flow is verified and the
difference between EVAPORATOR PRESSURE and
CONDENSER PRESSURE is more than 41.3 kPa for
ENTERING COND WATER temperature greater than
the TOWER FAN HIGH SETPOINT (SETPOINT menu,
default (3.9°C).
The TOWER FAN RELAY HIGH is turned off when the
condenser pump is off, flow is stopped, or the EVAPORATOR
REFRIG TEMP is less than the EVAP REF OVERRIDE
TEMP and ENTERING CONDENSER WATER is less
than 1.1°C, or the difference between EVAPORATOR
PRESSURE and CONDENSER PRESSURE is less than
193 kPa, and ENTERING CONDENSER WATER tempe-
rature is less than TOWER FAN HIGH SETPOINT minus
1.7 K.
The TOWER FAN RELAY LOW and TOWER FAN RELAY
HIGH parameters are accessed from the STARTUP screen.
IMPORTANT: A field-supplied water temperature control
system for condenser water should be installed. The system
should maintain the leaving condenser water temperature
at a temperature that is at least 11 K above the leaving
chilled water temperature.
CAUTION: The tower fan relay control is not a substitute
for a condenser water temperature control. When used with
a water temperature control system, the tower fan relay
control can be used to help prevent low condenser water
temperatures.
5.21 - Auto. Restart after power failure
This option may be enabled or disabled and may be viewed
or modified on the OPTIONS screen, which is accessed
from the EQUIPMENT CONFIGURATION table. If the
AUTO RESTART OPTION is enabled, the chiller will
start up automatically after a power failure has occurred,
generating one of the following faults: single cycle dropout
(if enabled), line current imbalance, high line voltage, low
line voltage, low DC bus voltage, high DC bus voltage, VFD
power on reset, and ICVC power on reset (alerts 143-148,
165, and 166). With this feature enabled, these faults are
treated as alerts instead of alarms, so start-up proceeds as
soon as the condition is rectified. The 15 and 1-minute start
inhibit timers are ignored during this type of start-up, and
the STARTS IN 1 HOURS counter is not incremented.
4
When power is restored after the power failure and if the
compressor had been running, the oil pump will energise
for one minute before energising the evaporator pump.
AUTO RESTART will then continue like a normal start-up.
If power to the ICVC module has been off for more than 3
hours or the timeclock has been set for the first time, start
the compressor with the slowest TEMP PULLDOWN
DEG/MIN rate possible in order to minimise oil foaming.
The oil pump is energised occasionally during the time the
oil is being brought up to proper temperature in order to
eliminate refrigerant that has migrated to the oil sump
during the power failure. The pump turns on for 30 seconds at
the end of every 30-minute period until the chiller is started.
5.22 - Water/brine reset
Chilled water capacity control is based on achieving and
maintaining a CONTROL POINT temperature, which is
the sum of the LCW SET POINT or ECW SETPOINT
(from the SETPOINT screen) and a Water/Brine Reset
value, if any. CONTROL POINT is limited to a minimum
of +1.7°C for water, or -1.°C for brine. Three types of
chilled water or brine reset are available and can be viewed
or modified on the TEMP_CTL screen, which is accessed
from the EQUIPMENT SERVICE table.
The ICVC default screen indicates when the chilled water
reset is active. TEMPERATURE RESET on the MAINSTAT
screen indicates the amount of reset. The CONTROL
POINT will be determined by adding the TEMPERATURE
RESET to the SETPOINT. To activate a reset type, access the
TEMP_CTL screen and input all configuration information
for that reset type. Then, input the reset type number (1, , or
3) in the SELECT/ ENABLE RESET TYPE input line.
RESET TYPE 1: 4 to 0 mA (1 to 5 V d.c.) TEMPERA-
TURE RESET – Reset type 1 is an “automatic” reset using a
4 to 0 mA or 1 to 5 V d.c. analogue input signal provided
from any external sensor, controller, or other device which is
appropriately configured. Reset type 1 permits up to ±16.7 K
of reset to the chilled water set point. Inputs are wired to
terminals J5-3 (–) and J5-4 (+) on the CCM (for 4-0 mA
input). In order to utilise a 1 to 5 V d.c. input, a 50 ohm
resistor must be wired in series with the + input lead (J5-4).
For either input type, SW DIP switches should be set in the
ON (up) position. Inputs equivalent to less than 4 mA result
in no reset, and inputs exceeding 0 mA are treated as 0 mA.
RESET TYPE : REMOTE TEMPERATURE RESET
— Reset type is an automatic chilled water temperature
reset based on a remote temperature sensor input signal.
Reset type permits ± 16 K of automatic reset to the set
point based on a temperature sensor wired to the CCM
module (see wiring diagrams or certified drawings). The
temperature sensor must be wired to terminal J4-13 and
J4-14. To configure reset type , enter the temperature of
the remote sensor at the point where no temperature reset
will occur (REMOTE TEMP –> NO RESET). Next, enter
the temperature at which the full amount of reset will occur
(REMOTE TEMP –> FULL RESET). Then, enter the
maximum amount of reset required to operate the chiller
(DEGREES RESET). Reset type can now be activated.
- Quick Links:
- Alarms and Alerts
- Troubleshooting Guide
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