System information

16
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 6.
Table 6 — 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 , 3-wire) based on IOB channel configurations. The tem-
perature sensor range is –40 F (–40 C) to 245 F (118 C). See
Table 7.
Table 7 — Temperature Sensors
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.
HGBP VALVE — The hot gas bypass function artificially
loads the chiller and keeps it running under low load condi-
tions or helps to prevent surge conditions. Since this function
can also reduce the operating efficiency of the machine, this is
a user-selectable and configurable 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 if necessary.
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 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 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-en-
abled web browser. See the section Touch Screen Settings for
the Controller on page 52 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 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 on
page 30 and contact your network administrator.
PRESSURE
TRANSDUCER
PURPOSE
Evaporator Measures evaporator pressure
Condenser Measures condenser pressure
Economizer Measures economizer pressure
Oil Supply Measures oil pressure in the oil discharge
piping
Oil Sump Measures oil pressure in the oil sump
Evaporator Entering
Water
(Optional) Measures pressure of evapora-
tor entering water
Evaporator Leaving
Water
(Optional) Measures pressure of evapora-
tor leaving water
Condenser Entering
Water
(Optional) Measures pressure of con-
denser entering water
Condenser Leaving
Water
(Optional) Measures pressure of con-
denser leaving water
TEMPERATURE
SENSOR
PURPOSE
Entering Chilled
Water
Measures entering evaporator water tem-
perature
Leaving Chilled
Water
Measures leaving evaporator water tem-
perature
Entering Condenser
Water
Measures entering condenser water tem-
perature
Leaving Condenser
Water
Measures leaving condenser water tem-
perature
Evaporator Refriger-
ant Liquid
Measures evaporator refrigerant liquid
temperature
Compressor Dis-
charge
Measures compressor discharge tempera-
ture
Low Speed Motor
End Bearing
Measures temperature of the low speed
motor end bearing temperature
Low Speed Com-
pressor End Bearing
Measures temperature of the low speed
compressor end bearing temperature
High Speed Motor
End Bearing
Measures temperature of the high speed
motor end bearing temperature
High Speed Com-
pressor End Bearing
Measures temperature of the high speed
compressor end bearing temperature
Motor Winding End Three sensors measure the temperature
of each phase of the compressor motor
Oil Sump Measures the compressor sump oil tem-
perature
Oil Supply Measures the oil temperature in the oil dis-
charge piping