Carrier 30GN040-420 operating instructions Safety Considerations, General, Major System Components

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, quali®ed 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 identi®ed as circuits A and B, and com- pressors are identi®ed 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 speci®c 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 Ð Unit Sizes and Modular Combinations

UNIT MODEL	NOMINAL	SECTION A	SECTION B
30GN	TONS	UNIT 30GN	UNIT 30GN
040	40	Ð	Ð
045	45	Ð	Ð
050	50	Ð	Ð
060	60	Ð	Ð
070	70	Ð	Ð
080	80	Ð	Ð
090	90	Ð	Ð
100	100	Ð	Ð
110	110	Ð	Ð
130	125	Ð	Ð
150	145	Ð	Ð
170	160	Ð	Ð
190	180	Ð	Ð
210	200	Ð	Ð
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 ¯uid temperature set point. It automatically positions the EXV to maintain the speci®ed 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 Ð 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

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