Control Transformers (Ti, T2); Optional Transformer (T3); Sensors - Carrier 19XRV Start-Up, Operation And Maintenance Instructions Manual

CHILLER CONTROL MODULE (CCM) -- This module is
located in file control panel. Tile CCM provides the input and
outputs necessa U to control the chillel: This module monitors
refiigerant pressure, entering and leaving water temperatures,
and outputs control for the guide vane actuator, oil heaters, and
oil pump. The CCM is the connection point for optional
demand limit, chilled water reset, remote temperature reset,
refi'igerant leak sensor and motor kilowatt output.
OIL HEATER CONTACTOR (IC) -- This contactor is lo-
cated in the power panel (Fig. 10) and operates the heater tit
115 v. It is controlled by the PIC III to maintain oil temperature
during chiller shutdown. Refer to the control panel wiring
schematic.
OIL PUMP CONTACTOR (2C) -- This contactor is located
in the power panel. It operates all 380 to 480-v oil pumps.
The PIC HI energizes the contactor to turn on the oil pump as
necessm-y.
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 during low load, high lill conditions.
CONTROL TRANSFORMERS (TI, T2)- These transform-
ers convert incoming control voltage to 24 vac power for the
3 power panel contactor relays, CCM, and ICVC.
OPTIONAL TRANSFORMER (T3)--This transformer pro-
vides control power to DataPort'rWDataLINK
TM
modules.
SENSORS -- Throe types of temperature sensors am used:
Figure 11 shows a typictd temperature sensor with which
sensor wells am not used, in systems having a ICVC controllel:
For this type the sensor cable can be easily disconnected fiom
the sensok which is in direct contact with the fluid.
Figure 12 shows a typictd temperature sensor for which
sensor wells am used, in systems having an ICVC controllel:
For this type the sensor cable cannot be separated from the
sensor itself, but the sensor can be readily removed from the
well without breaking into the fluid boun&u-y.
The third type of temperature sensor is a thermistok which
is installed either in the motor windings or tit the thrust bearing
within the compressol: Both of these have redun&mt sensors
such flint if one fails, the other can be connected external to the
machine. See NiNe 3 for a list of stan&trd instrumentation
sensors.
The PIC [II control determines refrigerant temperature in
the condenser and evaporator fi_m pressure in those vessels,
mad fi_m the conesponding pressure transducers. See Fig. 13.
The pressure values are converted to the equivtdent saturation
temperatures for R-134a refrigerant. When the chiller is run-
ning, if the computed value for EVAPORATOR REFRIG
TEMP is greater than, or within 0.6° F (0.33 ° C) of the LEAV-
ING CHILLED WATER temperature, its value is displayed as
0.6° F (0.33° C) below LEAVING CHILLED WATER tempe>
atum. When the chiller is running, if the computed value for
CONDENSER REFRIG TEMP is less than, or within 1.2° F
(0.67 ° C) of the LEAVING COND WATER temperature, its
value is displayed as 1.2° F (0.67 ° C) above LEAVING COND
WATER temperature.
Table 3 -- Standard Instrumentation Sensors
TYPE LOCATION MONITORED REMARKS
Entering chilled water Cooler inlet nozzle
Leaving chilled water Cooler outlet nozzle
Entering condenser water Condenser inlet nozzle
Leaving condenser water Condenser outlet nozzle
Temperature Evaporator saturation Sensor well on bottom of evaporator
Compressor discharge Compressor volute
Oil sump Compressor oil sump
Compressor thrust bearing Redundant sensor provided
Motor winding Redundant sensor provided
Evaporator Relief valve tee
Condenser Relief valve tee
Oil sump Compressor oil sump
Oil sump discharge Oil pump discharge line
Pressure Diffuser (Compressor internal) Only in machines equipped with split ring diffusers
Entering chilled water (Optional) Cooler inlet nozzle
Leaving chilled water (Optional) Cooler outlet nozzle
Entering condenser water (Optional) Condenser inlet nozzle
Leaving condenser water (Optional) Condenser outlet nozzle
Angular Position Guide vane actuator Potentiometer inside of actuator
Pressure Switch High condenser (discharge) pressure Compressor volute, wired into the starter control circuit
Temperature Switch Oil pump motor winding temperature Wired into the oil pump control circuit
13