Specifications
61
Cooler Entering Water Sensor
— On all sizes, this thermistor
is factory-installed in a well in the entering water nozzle of the
cooler.
Condenser Leaving Water Sensor
— On all sizes with heat
machine options, this thermistor is installed in a well in the
leaving water nozzle of the condenser. See Fig. 45 and 46.
Condenser Entering Water Sensor
— On all sizes with heat
machine options, this thermistor is factory-installed in a well in
the entering water nozzle of the condenser.
Compressor Suction Gas Temperature
— On all sizes, this
thermistor is factory-installed in a well located on the compres-
sor of each circuit. There is one thermistor for each circuit.
Compressor Discharge Gas Temperature
— On all sizes, this
thermistor is factory-installed in a well located in the discharge
end of the compressor for the circuit. There is one thermistor
for each circuit.
Economizer Temperature
(sizes 175, 200, 250, 275, 300,
350, 400 only) — On all sizes, this thermistor is factory-
installed in a friction fit well located in the economizer line for
the circuit. There is one thermistor for each circuit.
Compressor Motor Temperature
— On all sizes, this therm-
istor is embedded in the motor windings. There are two therm-
istors in each compressor. One spare is provided.
Remote Space Temperature
— This sensor (part no.
33ZCT55SPT) is a field-installed accessory mounted in the in-
door space and is used for water temperature reset. The sensor
should be installed as a wall-mounted thermostat would be (in
the conditioned space where it will not be subjected to either a
cooling or heating source or direct exposure to sunlight, and 4
to 5 ft above the floor).
Space temperature sensor wires are to be connected to
terminals in the unit main control box. The space temperature
sensor includes a terminal block (SEN) and a RJ11 female con-
nector. The RJ11 connector is used to access the Carrier Com-
fort Network
®
(CCN) system at the sensor. See Fig. 45 and 46.
To connect the space temperature sensor (see Fig. 47):
1. Using a 20 AWG twisted pair conductor cable rated for
the application, connect one wire of the twisted pair to
one SEN terminal and connect the other wire to the other
SEN terminal located under the cover of the space
temperature sensor.
2. Connect the other ends of the wires to terminals 7 and 8
on TB6 located in the unit control box.
Units on the CCN can be monitored from the space at the
sensor through the RJ11 connector, if desired. To wire the RJ11
connector into the CCN:
1. Cut the CCN wire and strip ends of the red (+), white
(ground), and black (–) conductors. (If another wire color
scheme is used, strip ends of appropriate wires.)
2. Insert and secure the red (+) wire to terminal 5 of the
space temperature sensor terminal block.
3. Insert and secure the white (ground) wire to terminal 4 of
the space temperature sensor.
4. Insert and secure the black (–) wire to terminal 2 of the
space temperature sensor.
5. Connect the other end of the communication bus cable to
the remainder of the CCN communication bus.
NOTE: The Energy Management Module (EMM) is required
for this accessory.
TRANSDUCERS — There are four pressure transducers per
circuit (3 per circuit for sizes 150 and 325), and two different
types of transducers: low pressure (green connector) and high
pressure (black connector). See Fig. 44 for transducer loca-
tions.
Low-pressure type:
• Suction pressure transducer (SPT)
• Economizer pressure transducer (EPT)
High-pressure type:
• Discharge pressure transducer (DPT)
• Oil pressure transducer (OPT)
Table 38 — Thermistor Identification
*SGTA and SGTB for 30XW150-325, 375 units are connected to the EXV1 board.
IMPORTANT: The cable selected for the RJ11
connector wiring MUST be identical to the CCN
communication bus wire used for the entire network.
Refer to Table 11 for acceptable wiring.
THERMISTOR ID DESCRIPTION RESISTANCE AT 77 F (25 C) CONNECTION POINT
EWT Evaporator Entering Water Thermistor 5k MBB-J6-CH2
LWT Evaporator Leaving Water Thermistor 5k MBB-J6-CH1
CEWT Condenser Entering Water Thermistor 5k MBB-J6-CH4
CLWT Condenser Leaving Water Thermistor 5k MBB-J6-CH5
SGTA* Circuit A Suction Gas Thermistor 5k EXV1-J3-THA
SGTB* Circuit B Suction Gas Thermistor 5k EXV2-J3-THA
DGTA Circuit A Discharge Gas Thermistor 5k CPM-A-J9-CH02
DGTB Circuit B Discharge Gas Thermistor 5k CPM-B-J9-CH02
ECTA Circuit A Economizer Thermistor 5k EXV1-J3-THB
ECTB Circuit B Economizer Thermistor 5k EXV2-J3-THB
DUAL Dual Chiller LWT Thermistor 5k MBB-J6-CH3
CAMT Circuit A Motor Temperature 5k CPM-A-J9-CH01
CBMT Circuit B Motor Temperature 5k CPM-B-J9-CH01
SPT Space Temperature Thermistor 10k EMM-J6-CH2