Ramp Loading Control - Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual

MONITORED PARAMETER
Starts Limit Exceeded
Low Chilled Water Flow
Low Cond Water Flow
High Approach - Evaporator
Condenser
VFD - High VFD Speed
Failure to Stop
Rectifier - High Temperature
Overcurrent
Power Fault
Inverter - High Temperature
Power Fault
Inductor - Overtemperature Switch
DC Bus Voltage - High
Low
Ground Fault
Optional Limits - Spare
Temperature
Guide Vane Position
Low Discharge Superheat
Humidity - Dew Prevention
Sensor Fault

5.7 - Ramp loading control

The ramp loading control slows down the rate at which the
compressor loads up. This control can prevent the com-
pressor from loading up during the short period of time
when the chiller is started and the chilled water loop
temperature has to be brought down to the CONTROL
POINT. This helps reduce electrical demand charges by
slowly bringing the chilled water to CONTROL POINT.
However, the total power draw during this period remains
almost unchanged.
There are several methods of ramp loading with the PIC III.
Ramp loading can be based on LEAVING CHILLED
WATER, ENTERING CHILLED WATER, PERCENT
LINE CURENT,or PERCENT MOTOR KILOWATTS.
PULLDOWN RAMP TYPE is selected from the RAMP_
_DEM screen.
38
Table 5 - Protective limits and control settings (continued)
ALARM/ALERT LIMIT
100 More than 8 starts in 12 hours
229 CHILLED LIQUID FLOW = FALSE after CHILLED
WATER PUMP = ON & WATER FLOW VERIFY TIME
elapsed
230 COND WATER FLOW = FALSE after COND WATER
PUMP = ON & WATER FLOW VERIFY TIME elapsed
162 EVAPORATOR APPROACH > EVAP APPROACH
ALERT and startup complete
163 CONDENSER APPROACH > COND APPROACH
ALERT and startup complete
245 ACTUAL VFD SPEED > VFD SPEED OUTPUT + 10% Preset Alarm, Must be outside +10% threshold for 75
204 PERCENT LOAD CURRENT >15% and VFDSTART =
NO for 20 seconds
218 RECTIFIER TEMPERATURE limit exceeded
110 RECTIFIER TEMPERATURE > RECTIFIER TEMP
OVERRIDE – 11.1 K)
241 Rectifier current limit exceeded
200 IGBT current limit exceeded or a fault was detected in
the rectifier
219 INVERTER TEMPERATURE limit exceeded
111 INVERTER TEMPERATURE > INVERTER TEMP
OVERRIDE –11.1 K
286 Inverter current limit exceeded
201 IGBT current limit exceeded
256 Inductor temperature limit exceeded
205/166 DC BUS VOLTAGE Limit Exceeded
215 DC BUS VOLTAGE < 407 V d.c. at 400/480 V Line
Side Voltage
220 GROUND FAULT CURRENT > 7% of Drive Rated
Amps Sensed
158,159,248,249 SPARE TEMPERATURE > SPARE TEMP LIMIT
253 ACTUAL GUIDE VANE POS > 4% after 4 minutes of
closing
ACTUAL GUIDE VANE POSITION < 0.045 V after
startup complete
ACTUAL GUIDE VANE POSITION > 3.15 V after
startup complete
ACTUAL GUIDE VANE POSITION < –1% after startup
complete
ACTUAL GUIDE VANE POSITION > 103% after
startup complete
240 DISCHARGE SUPERHEAT < SUPERHEAT
REQUIRED –1.7 K for 60 seconds
255 VFD COOLANT FLOW = 0% and VFD COLD PLATE
TEMPERATURE < T dewpoint + 0.3 K or VFD
COOLANT FLOW = 0% and there is a Rectifier
Overtemperature or Inverter Overtemperature Alarm
168 HUMIDITY SENSOR INPUT > 4.5 V or HUMIDITY
SENSOR INPUT < 0.5 V
COMMENTS
Preset Prestart Alert
Optional Alarm, Configure WATER FLOW VERIFY TIME
in SETUP1 screen
Optional Alarm, Configure WATER FLOW VERIFY TIME
in SETUP1 screen
Configure EVAP APPROACH ALERT in SETUP1 screen
Configure COND APPROACH ALERT in SETUP1
screen
seconds
Preset Alarm, PERCENT LOAD CURRENT = AVERAGE
LOAD CURRENT/MOTOR RATED LOAD AMPS
Preset Alarm, Configure RECTIFIER TEMP OVERRIDE
in SETUP1 screen
Prestart Alert, Configure RECTIFIER TEMP OVERRIDE
in SETUP1 screen
Preset Alarm
Preset Alarm
Preset Alarm, Configure INVERTER TEMP OVERRIDE
in SETUP1 screen
Prestart Alert, Configure INVERTER TEMP OVERRIDE
in SETUP1 screen
Preset Alarm
Preset Alarm
Preset Alarm, Temperature switch in reactor has opened
Preset Alarm/Alert
Preset Alarm
Preset Alarm
Optional Alarm/Alert, Configure SPARE TEMP ENABLE
and SPARE TEMP LIMIT in SETUP1 screen
Preset Alarm
Preset Alarm
Preset Alarm
Preset Alarm
Preset Alarm
Preset Alarm, DISCHARGE SUPERHEAT = COMP
DISCHARGE TEMP – CONDENSER REFRIG TEMP
Preset Alarm
Preset Alert
1. temperature ramp loading (TEMP PULLDOWN
DEG/MIN) limits the rate at which either LEAVING
CHILLED WATER or ENTERING CHILLED
WATER temperature decreases by an operator-
configured rate from the TEMP_CTL screen.
NOTE: If chiller control power has been off for 3 hours or
more, the next start-up (only) will follow temperature ramp
loading using the minimum rate regardless of the ramp
loading method and rate which are configured in the screens.
This is used to maximise oil reclaim during start-up.
. Motor load ramp loading (AMPS OR KW RAMP %/
MIN) limits the rate at which the compressor motor
current or compressor motor load increases. The
AMPS OR KW RAMP %/MIN rate is configured by
the operator on the RAMP_DEM screen in line
current or motor kilowatts.