Chiller Control Module (Ccm); Vfd Power Module; Vfd Gateway Module; Oil Heater Contactor (1C) - Carrier AquaEdge 23XRV Start-Up, Operation And Maintenance Instructions Manual

CHILLER CONTROL MODULE (CCM) — This module is
located on the control panel in the control center. The CCM
provides the input and outputs necessary to control the chiller.
This module monitors refrigerant pressure, entering and
leaving liquid temperatures and pressures, and outputs control
for the oil reclaim valve, oil heaters, and oil pump. The CCM is
the connection point for optional demand limit, automatic
chilled liquid reset, 4 to 20 mA kW output, remote temperature
reset, and refrigerant leak sensor.
VFD POWER MODULE — This module is located in the
control center. The A/C line I/O assembly executes commands
from the ICVC for functions such as starting and stopping the
condenser and evaporator liquid pumps, tower fan and alarm
contacts. The Standard I/O Option Assembly monitors inputs
such as remote start contact, spare safety, and the high condens-
er pressure switch and provides the 4-20 mA Head Pressure
Reference Output. See Fig. 18 for control center layout for the
LF-2 VFD. See Fig. 19 for control center layout for Std Tier
VFD.
VFD GATEWAY MODULE — The VFD Gateway Module
translates the protocols between the ICVC, CCM and VFD.
This module also contains logic capable of an independent
safety shutdown. It shuts down the chiller if communications
with the ICVC are lost. See Fig. 20 for power module compo-
nent locations.
OIL HEATER CONTACTOR (1C) — This contactor is lo-
cated on the control panel (Fig. 21) and operates the heater at
115 V. It is controlled by the PIC III control system to maintain
oil temperature during chiller shutdown or to keep the oil sump
temperature at an acceptable level.
OIL PUMP CONTACTOR (2C) — This contactor is locat-
ed in the control panel (Fig. 21) and operates the oil pump. The
oil pump is controlled by the PIC III to provide oil pressure
during pre-lube and when the chiller is starting or running.

HOT GAS BYPASS CONTACTOR RELAY (3C)

(Optional) — This relay, located in the power panel, controls
the opening of the hot gas bypass valve. The PIC III energizes
the relay based on hot gas bypass algorithm settings.
SECOND STAGE OIL HEATER CONTACTOR (5C) —
This contactor is located in the control panel (Fig 22), and is
activated by PIC III to maintain oil quality at low temperature.
VAPORIZER HEATER CONTACTOR (6C) — This
tactor is located in the control panel (Fig. 21) and energizes the
surface mounted heater on the bottom of the vaporizer.
CONTROL TRANSFORMERS (T1, T2, T4) — Transform-
ers T1, T2 convert incoming control voltage to 24 vac power
for the power panel contactor relays, CCM, ICVC, and 21 vac
power for the optional UPC Open and LON modules. Trans-
former T4 (supplied only with P compressors) supplies power
to both the EXV and AUX1 boards. Circuit breakers CB-1A,
CB-1B, CB-2A and CB-2B for the control transformers are lo-
cated above the CCM.
EXV CONTROL MODULE (PD4-EXV) — This module is
supplied with P compressors only. It is located near the top of
the control panel near the T4 control transformer. It provides
the input and outputs for the condenser EXV, economizer EXV
and economizer gas temperature.
AUXILIARY CONTROL MODULE (PD4-AUX1) — This
module is supplied with P compressors only. It is located near
the PD4-EXV board. This board communicates with the PD4-
EXV board and the CCM board, and provides the input and
output for the condenser level sensor (0 to 5 v proportional sig-
nal).
ELECTRONIC EXPANSION VALVE (P compressors only,
heat exchanger frame size A and B) — High pressure refriger-
ant enters the EXV and goes through the variable orifice. Re-
frigerant flow control for different operating conditions is con-
trolled by an actuator that modulates the valve opening. The
stepper motor moves in increments and is controlled by the
EXV control module. As the stepper motor rotates, motion is
transferred into linear movement by the lead screw. The main
EXV stepper motor has 3810 total steps, while the optional
economizer EXV has 2625 steps. See Fig. 23.
Main EXV Control— The valve is modulated to achieve the
condenser level set point by a continuous loop that compares
desired level to sensed level. At initial start-up the valve posi-
tion is driven to the start position and is held at this position for
approximately 2 minutes or as defined by the start delay set-
ting, after which the level control algorithm takes over. After
shutdown, the EXV will be driven to the condenser EXV start
position which will allow pressure equalization between cooler
and condenser. Default control parameters can be adjusted in
SETUP5.
NOTE: Changing the default values of many of the values in
SETUP4 and SETUP5 associated with the EXV control is not
recommended without support from Service Engineering.
Economizer EXV Control (Option)
EXV is activated at approximately 75% speed or as configured
when Actual VFD Speed is greater than Economizer Activate
Speed. After this, it is controlled to maintain the economizer
superheat set point that provides gas flow to the compressor.
When it deactivates, or if the Economizer Option is disabled,
the valve is fully closed. If the Economizer Option is enabled
then the EXV control logic algorithm will be active 5 minutes
after completion of startup. Default parameters can be adjusted
in SETUP4.
NOTE: Changing the default values of many of the values in
SETUP4 and SETUP5 associated with the EXV control is not
recommended without support from Service Engineering.
CONDENSER LEVEL SENSOR (P compressors only, heat
exchanger frame size A and B) — This sensor monitors the
liquid level in the condenser and transmits a continuous 0 to 5 v
signal proportional to the liquid level in the condenser sensing
chamber. See Fig. 5.
con-
Table 2 — Major PIC III Control Components and
PIC III COMPONENT
International Chiller Visual
Controller (ICVC) and Display

VFD Power Module

Chiller Control Module (CCM)

Oil Heater Contactor (1C)

Oil Heater Contactor, 1000 W (5C)

Oil Pump Contactor (2C)

Hot Gas Bypass Relay (3C)
(Optional)
Control Transformers (T1, T2)
Control Transformer Circuit Breakers
(CB-1A, CB-1B, CB-2A, CB-2B)
EXV Control Transformer (T4)
Temperature Sensors

Condenser Level Sensor

Pressure Transducers

Vaporizer Heater Contactor (6C)

Auxiliary Control Module
19
— The economizer
Panel Locations
PANEL LOCATION
Control Center Door
Inside Control Center
Control Panel
Control Panel
Control Panel
Control Panel
Control Panel
Control Panel
Control Panel
See Fig. 22
See Fig. 5-7 and 15
See Fig. 5
See Fig. 5-7 and 16
Control Panel
Near PD-4 EXV Board