Safety considerations, General, Major system components processor module – Carrier FLOTRONIC II 30GN040-420 User Manual
Page 2

SAFETY CONSIDERATIONS
Installing, starting up, and servicing this equipment can
be hazardous due to system pressures, electrical compo-
nents, and equipment location (roof, elevated structures, etc.).
Only trained, qualified installers and service mechanics should
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. Fol-
low all safety codes. Wear safety glasses and work gloves.
Use care in handling, rigging, and setting this equipment,
and in handling all electrical components.
Electrical shock can cause personal injury and death.
Shut off all power to this equipment during installation
and service. There may be more than one disconnect
switch. Tag all disconnect locations to alert others not
to restore power until work is completed.
This unit uses a microprocessor-based electronic con-
trol system. Do not use jumpers or other tools to short
out components, or to bypass or otherwise depart from
recommended procedures. Any short-to-ground of the
control board or accompanying wiring may destroy the
electronic modules or electrical components.
GENERAL
IMPORTANT: This publication contains controls, op-
eration and troubleshooting data for 30GN040-420
Flotronic™ II chillers.
Circuits are identified as circuits A and B, and com-
pressors are identified as A1, A2, etc. in circuit A, and
B1, B2, etc. in circuit B.
Use this guide in conjunction with separate Instal-
lation Instructions booklet packaged with the unit.
The 30G Series standard Flotronic II chillers feature
microprocessor-based electronic controls and an electronic
expansion valve (EXV) in each refrigeration circuit.
NOTE: The 30GN040 and 045 chillers with a factory-
installed brine option have thermal expansion valves (TXV)
instead of the EXV.
Unit sizes 230-420 are modular units which are shipped
as separate sections (modules A and B). Installation instruc-
tions specific to these units are shipped inside the individual
modules. See Table 1 for a listing of unit sizes and modular
combinations. For modules 230B-315B, follow all general
instructions as noted for unit sizes 080-110. For all remain-
ing modules, follow instructions for unit sizes 130-210.
Table 1 — Unit Sizes and Modular Combinations
UNIT MODEL
30GN
NOMINAL
TONS
SECTION A
UNIT 30GN
SECTION B
UNIT 30GN
040
40
—
—
045
45
—
—
050
50
—
—
060
60
—
—
070
70
—
—
080
80
—
—
090
90
—
—
100
100
—
—
110
110
—
—
130
125
—
—
150
145
—
—
170
160
—
—
190
180
—
—
210
200
—
—
230
220
150
080
245
230
150
090
255
240
150
100
270
260
170
100
290
280
190
110
315
300
210
110
330
325
170
170
360
350
190
190/170*
390
380
210
190
420
400
210
210
*60 Hz units/50 Hz units.
The Flotronic II control system cycles compressor un-
loaders and/or compressors to maintain the selected leaving
fluid temperature set point. It automatically positions the EXV
to maintain the specified refrigerant superheat entering the
compressor cylinders. It also cycles condenser fans on and
off to maintain suitable head pressure for each circuit. Safe-
ties are continuously monitored to prevent the unit from op-
erating under unsafe conditions. A scheduling function, pro-
grammed by the user, controls the unit occupied/unoccupied
schedule. The control also operates a test program that al-
lows the operator to check output signals and ensure com-
ponents are operable.
The control system consists of a processor module (PSIO),
a low-voltage relay module (DSIO-LV), 2 EXVs, an EXV
driver module (DSIO-EXV), a 6-pack relay board, a keypad
and display module (also called HSIO or LID), thermistors,
and transducers to provide inputs to the microprocessor. A
standard options module (SIO) is used to provide additional
functions. See Fig. 1 for a typical 30GN Control Panel.
MAJOR SYSTEM COMPONENTS
Processor Module —
This module contains the oper-
ating software and controls the operation of the machine. It
continuously monitors information received from the vari-
ous transducers and thermistors and communicates with the
relay modules and 6-pack relay board to increase or de-
crease the active stages of capacity. The processor module
2