12
Sensors
PRESSURE TRANSDUCERS — Pressure transducers mea-
sure and control the pressures in the unit. These electronic sen-
sors deliver 0 to 5 VDC. The transducers can be calibrated
through the controller. The pressure transducers are connected
to the IOBs. See Table 7.
Table 7 — Pressure Transducers
TEMPERATURE SENSORS — The system uses electronic
sensors to measure and control the temperatures in the unit.
There are three types of temperature sensors: 5K thermistor,
10K thermistor, and RTD (resistance temperature detector,
100 ohm, 3-wire) based on IOB channel configurations. The
temperature sensor range is –40 F (–40 C) to 245 F (118 C).
See Table 8.
Table 8 — Temperature Sensors
NOTE: Text in parentheses indicates applicable product.
Controls Outputs
EVAPORATOR/CONDENSER WATER PUMP — The
controller can regulate an optional evaporator/condenser
water pump.
INLET GUIDE VANE — The inlet guide vane adjusts the
refrigerant vapor flow into the compressor to adapt to change
in the operating conditions of the machine. To adjust the refrig-
erant flow, the guide vane opens or closes to vary the cross-
section of the refrigerant path. The high degree of accuracy
with which the guide vane is positioned ensures that the flow
of refrigerant is precisely controlled.
ECONOMIZER DAMPER VALVE — The economizer
damper control opens or closes the economizer damper valve
to maintain a minimum refrigerant pressure difference between
the evaporator and economizer.
ENVELOP CONTROL/HGBP VALVE — The hot gas
bypass function artificially loads the chiller and keeps it run-
ning under low load conditions or helps to prevent surge condi-
tions. Since this function can also reduce the operating
efficiency of the machine, this is a user-selectable and configu-
rable option.
VFD — The VFD modifies motor frequency to allow com-
pressor start-up and capacity control. The VFD controls con-
tinually monitor parameters in order to ensure compressor
protection. Should a problem occur, the controller triggers an
alarm and the compressor is stopped.
PIC 5 USER INTERFACE
The PIC 5 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 inter-
face 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 au-
thorized at the same time. When two users are connected si-
multaneously, there is no priority between 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 the section Touch Screen Set-
tings for the Controller on page 49 for configuration in-
structions. 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 PIC 5 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 PIC 5 interface. For more
information on the web browser and Java platform configura-
tion, see the Diagnostics and Troubleshooting section.
PRESSURE
TRANSDUCER
PURPOSE
Evaporator
Measures evaporator pressure
Condenser
Measures condenser pressure
Economizer
Measures economizer pressure
(if economizer)
Oil Supply
Measures oil pressure in the oil discharge
piping
Oil Sump
Measures oil pressure in the oil sump
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
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
Low Speed Motor End
Bearing
Measures temperature of the low speed
motor end bearing temperature (02XR6/7)
Low Speed Compres-
sor End Bearing
Measures temperature of the low speed
compressor end bearing temperature
(02XR6/7)
High Speed Motor End
Bearing
Measures temperature of the high speed
motor end bearing temperature (02XR6/7)
High Speed Compres-
sor End Bearing
Measures temperature of the high speed
compressor end bearing temperature
(02XR6/7)
Motor Winding End
Sensor(s) measure the temperature of
each phase of the compressor motor
Oil Sump
Measures the compressor sump oil
temperature
Oil Supply
Measures the oil temperature in the oil
discharge piping
Compressor thrust
bearing oil tempera-
ture sensor
Measure compressor thrust bearing oil
temperature (02XR2-5, 02XRE)
