System information
2
rigging, and setting this equipment, and in handling all electri-
cal components.
GENERAL
This publication contains operation and troubleshooting in-
formation for PIC (Product Integrated Control) 5, a system for
controlling two-stage 19XR semi-hermetic centrifugal liquid
chillers.
The PIC 5 control system monitors and controls all opera-
tions 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 and minus the dead band by sens-
ing the water or brine temperature and regulating the inlet
guide vane via a mechanically linked actuator motor, and regu-
lating VFD (variable frequency drive) speed if the compressor
is powered by a variable speed drive. The guide vane is a vari-
able flow pre-whirl assembly that controls the refrigeration ef-
fect in the cooler by regulating the amount of refrigerant vapor
flow into the compressor. An increase in guide vane opening
increases capacity. A decrease in guide vane opening decreases
capacity. The microprocessor-based control center protects the
chiller by monitoring the digital and analog inputs and execut-
ing capacity overrides or safety shutdowns as necessary.
The PIC 5 control system also provides access to a Control
Test function covering all outputs except compressor relay out-
puts.
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.
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. Fig-
ures 2-5 show ISM wiring diagrams.
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
dissipate body electrostatic charge before working inside
control 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 com-
munications. The PIC 5 control boards have been tested
and found to comply with the limits for a Class A comput-
ing device pursuant to International Standard in North
America EN 61000-2/3 which are designed to provide rea-
sonable 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 interfer-
ence.
Always store and transport replacement or defective boards
in anti-static shipping bag.
CCN — Carrier Comfort Network
®
CCN mode — Operating type: CCN
ECDW — Entering Condenser Water
ECW — Entering Chilled Water
HGBP — Hot Gas Bypass
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
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 dam-
aged.