11
Communication Cables
The communication transmission cables have the following elec-
trical characteristics:
• 2 signal conductors and one ground conductor of 20 AWG
or larger, 100% shielded
• One tinned copper braid (65% coverage)
Recommended cables are shown below:
To avoid potential interference, route communication cables as far
away as possible from high voltage cable and other likely distur-
bances. Always separate communication cables from other cables
and always run wiring as directly as possible.
Sensors
PRESSURE TRANSDUCERS
Pressure transducers measure and control the pressures in the unit.
These electronic sensors deliver 0 to 5 VDC. The pressure trans-
ducers are connected to the IOBs/SIOB. See Table 4.
TEMPERATURE SENSORS
The system uses electronic sensors to measure and control the
temperatures in the unit. The temperature sensors are 5K Ohm
thermistors. The temperature sensor range is –40°F (–40°C) to
245°F (118°C). See Table 5. Pressure transducers and thermistors
can be calibrated in the Quick Test Menu. Pressure transducers
can be adjusted up to 5 psi (34.5 kPa) and thermistors can be ad-
justed up to ±5°F (2.8°C).
Controls Outputs
EVAPORATOR/CONDENSER WATER PUMP
The controller regulates the evaporator/condenser water pump.
Note that Carrier requires full or parallel pump control since Carri-
er controls utilize the pumps for freeze protection and high pres-
sure control.
ENVELOPE/HGBP CONTROL VALVE
The on/off HGBP valve artificially loads the chiller and keeps it
running under low load conditions.
VFD
The VFD modifies motor frequency to allow compressor start-up
and capacity control. The VFD controls continually monitor pa-
rameters to ensure compressor protection. If a problem occurs, the
controller triggers an alarm and the compressor is stopped.
USER INTERFACE
The PIC6 Human Machine Interface (HMI) is a color 10.4-in.
TFT touch screen. Navigation is either direct from the touch
screen interface or by connecting to a web interface at the Ethernet
IP port of the controller. The navigation menus are the same for
both connection methods.
Web Connection
Two web connections may be authorized at the same time. When
two users are connected simultaneously, there is no priority be-
tween users; that is, the last modification is in effect regardless
of the user. Connection is from a personal computer using a
Java-enabled web browser. See “CONTROLLER SETTINGS”
on page 34 for configuration instructions.
The minimum browser configuration includes:
• Microsoft Internet Explorer (version 8 or higher) or Mozilla
Firefox (version 3.5.2 or higher). In the advanced connection
options, add the unit address to the address list. Do not use a
proxy server.
• Java platform (version 6 or higher). In the control panel,
deselect (uncheck) the option that allows storing tempo-
rary internet files and use a direct connection.
To access the PIC6 user interface, enter the IP address of the unit
in the address bar of the web browser. The IP address can be
viewed or changed from the PIC6 interface. For more information
on the web browser and Java platform configuration, see “DIAG-
NOSTICS AND TROUBLESHOOTING” on page 25.
USAGE CABLE
Intra-Building Belden 8772
High Temperature Belden 85240
Plenum Belden 89418
Modbus Communication Belden 3106A
Table 4 — Pressure Transducers
PRESSURE
TRANSDUCER
PURPOSE
Pump Supply Pressure Measures pressure at oil pump discharge.
Pump Sump Pressure Measures oil sump pressure.
Evaporator Measures evaporator pressure.
Condenser Measures condenser pressure.
Economizer Measures ec
onomizer pressure.
(For unit with TP compressor and economizer option only.)
Evaporator Water
Pressure Difference
(Optional) Measures pressure difference between entering
and leaving water.
Condenser Water
Pressure Difference
(Optional) Measures pressure difference between entering
and leaving water.
Evaporator Entering
Water
(Optional) Measures pressure of evaporator entering water.
Evaporator Leaving
Water
(Optional) Measures pressure of evaporator leaving water.
Condenser Entering
Water
(Optional) Measures pressure of condenser entering water.
Condenser Leaving
Water
(Optional) Measures pressure of condenser leaving water.
Table 5 — Temperature Sensors
TEMPERATURE SENSOR PURPOSE
Entering Chilled Water
Measures entering evaporator water
temperature
Leaving Chilled Water Measures leaving evaporator water temperature
Entering Condenser Water
Measures entering condenser water
temperature
Leaving Condenser Water Measures leaving condenser water temperature
Evaporator Refrigerant
Liquid
Measures evaporator refrigerant liquid
temperature
Compressor Discharge Measures compressor discharge temperature
Oil Sump Measures oil sump temperature
Vaporizer Temperature Measures temperature of oil leaving vaporizer
Chilled Water Supply (Optional)
a
NOTE(S):
a. Separate inputs used when the chiller is in network mode.
Measures temperature of chilled water supply
Chilled Water Return (Optional)
a
Measures temperature of chilled water return
Motor Winding
Measures temperature of each phase of
compressor motor
Economizer Gas
Measures gas temperature from economizer to
compressor (For unit with TP compressor and
economizer option only)
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