2
install, start up, and service this equipment. When working
on this equipment, observe precautions in the literature, and
on tags, stickers, and labels attached to the equipment, and
any other safety precautions that apply. Follow all safety
codes. Wear safety glasses and work gloves. Use care in han-
dling, rigging, and setting this equipment, and in handling
all electrical components.
GENERAL
This publication contains operation and troubleshooting in-
formation for PIC (Product Integrated Control) 5, a system for
controlling 19XR semi-hermetic centrifugal liquid chillers.
This publication is based on 19XRPIC5 Version 3.3 software
(SCG-SR-20M200320).
The PIC 5 control system monitors and controls all op-
erations of the chiller. The microprocessor control system
matches the capacity of the chiller to the cooling load
while providing state-of-the-art chiller protection. The
system controls cooling load within the set point plus or
minus the dead band by sensing the water or brine tem-
perature and regulating the inlet guide vane via a mechani-
cally linked actuator motor, and regulating VFD (variable
frequency drive) speed if the compressor is powered by a
variable speed drive. The guide vane is a variable flow
pre-whirl assembly that controls the refrigeration effect in
the cooler by regulating the amount of refrigerant vapor
flow into the compressor. An increase in guide vane open-
ing increases capacity. A decrease in guide vane opening
decreases capacity. The microprocessor-based control cen-
ter protects the chiller by monitoring the digital and analog
inputs and executing capacity overrides or safety shut-
downs as necessary.
The PIC 5 control system also provides access to a Con-
trol Test function covering all outputs except compressor re-
lay outputs.
Abbreviations Used in This Manual —
The fol-
lowing abbreviations are used in this manual:
HARDWARE
The PIC 5 control system consists of one main control
board, an ISM (integrated starter module), and four IOBs (in-
put/output board modules). All boards communicate via an in-
ternal LEN bus. PIC 5 is also compatible with unit-mounted
VFD options that do not utilize ISM. For this application a
LEN to Modbus* protocol converter module is required.
Main Control Board —
The main control board is sup-
plied from a 24 VAC supply reference to earth ground. In the
event of a power supply interrupt, the unit restarts automati-
cally without the need for an external command. However, any
faults active when the supply is interrupted are saved, and may
in certain cases prevent a circuit or unit from restarting. Figure
1 shows the main control interface and connectors.
ISM (Integrated Starter Module) —
The ISM is the
motor control module, supplied from a 115 VAC supply refer-
ence to earth ground. Table 1 lists ISM inputs and outputs.
ISM wiring diagrams are shown in Appendix E.
WARNING
Electrical shock can cause personal injury and death. Shut
off all power to this equipment during installation. Use lock
out/tag out procedures and be aware that there may be
more than one disconnect switch. Be sure to tag all discon-
nect locations to alert others not to restore power until work
is completed. Even when the main circuit breaker or isola-
tor is switched off, certain circuits may still be energized,
since they may be connected to a separate power source.
WARNING
Electrical currents cause components to get hot either tem-
porarily or permanently and may cause burns. Handle
power cable, electrical cables and conduits, terminal box
covers, and motor frames with great care.
CAUTION
This unit uses a microprocessor control system. Do not
short or jumper between terminations on circuit boards or
modules; control or board failure may result.
Be aware of electrostatic discharge (static electricity) when
handling or making contact with circuit boards or module
connections. Always touch a chassis (grounded) part to dis-
sipate body electrostatic charge before working inside con-
trol center.
Use extreme care when handling tools near boards and
when connecting or disconnecting terminal plugs. Circuit
boards can easily be damaged. Always hold boards by the
edges and avoid touching components and connections.
This equipment uses, and can radiate, radio frequency
energy. If not installed and used in accordance with the
instruction manual, it may cause interference to radio
communications. The PIC 5 control boards have been
tested and found to comply with the limits for a Class A
computing device pursuant to International Standard in
North America EN 61000-2/3 which are designed to
provide reasonable protection against such interference
when operated in a commercial environment. Operation
of this equipment in a residential area is likely to cause
interference, in which case the user, at his own expense,
will be required to take whatever measures may be
required to correct the interference.
Always store and transport replacement or defective boards
in anti-static shipping bag.
CCM
— Chiller Control Module
CCN
— Carrier Comfort Network
®
CCN mode — Operating mode: CCN
EC
— Envelop Control (Hot Gas Bypass)
ECDW
— Entering Condenser Water
ECW
— Entering Chilled Water
EXV
— Electronic Expansion Valve
HMI
— Human Machine Interface
I/O
— Input/Output
IOB
— Input/Output Board
ISM
— Integrated Starter Module
LCDW
— Leaving Condenser Water
LCW
— Leaving Chilled Water
LED
— Light-Emitting Diode
LEN
— Local Equipment Network (internal communica-
tion linking the main board to slave boards)
MCB
— Main Control Board
PIC
— Product Integrated Control
RLA
— Rated Load Amps
SRD
— Split Ring Diffuser
TFT
— Thin Film Transistor
VFD
— Variable Frequency Drive
UI
— User Interface
CAUTION
Maintain the correct polarity when connecting the
power supply to the boards. Otherwise, the boards may
be damaged.
*Modbus is a registered trademark of Schneider Electric.
