Unit installation
Table Of Contents
- Introduction
- Installation
- Physical Data
- Electrical Data
- Dimensional Data
- Startup
- Operation
- Global UNT Controller Installation and Operation
- General Description
- Optional Sensors
- Sensors and Transducers
- Control Wiring
- External Voltage Inputs
- Interlock Wiring
- Unit Set Points and Calibration
- Optional Sensors
- Field Wiring
- Power Wiring
- Power Supplies
- Analog input signals
- Digital input signals
- Remote Stop/Start
- Chilled Water Flow Switch
- Digital Outputs
- External Alarm Annunciator Circuitry
- PC Connection
- Software Identification
- Controller Inputs /Outputs
- Additional Global UNT Features
- Alarms
- Zone Terminal (Optional)
- Zone Terminal Glossary
- UNT Troubleshooting Chart
- MicroTech Controller Installation and Operation
- Sensors and transducers
- Control wiring
- Remote 4-20 milliamp signals
- Interlock wiring
- Unit set points and calibration
- Modem kit
- Lead-Lag
- Field Wiring
- Power Wiring
- Power Supplies
- Analog Input Signals
- Digital Input Signals
- Remote Stop/Start
- Chilled Water Flow Switch
- Digital Outputs
- Chilled Water Pump Relay
- External Alarm Annunciator Circuitry
- PC Connection
- Telephone line
- Software Identification
- Controller Inputs /Outputs
- Reset Options
- Soft Loading
- Manual Operation
- Compressor Staging
- Head Pressure Control
- Pumpdown Control
- Safety Systems
- Circuit Alarm Conditions
- System Alarm Conditions
- Sequence of Operation
- Start-Up and Shutdown
- Keypad / Display
- Menu Descriptions
- Trouble Analysis for the MicroTech
- Test Procedures
- Unit Maintenance
- Service

92 AGZ 035A through 065A IOMM AGZ-3
3. The charge can be added at any load condition between 25-100% load per circuit but at least two F
fans should be operating per refrigerant circuit if possible. The suction superheat should be in the
6°F-12°F (3.3°C-6.6°C) range.
4. Add sufficient charge to clear the liquid line sightglass and until all flashing stops in the sightglass.
Add an extra 15-20 lbs. of reserve to fill the subcooler if the compressor is operating at 50-100%
load.
5. Check the unit subcooling value by reading the liquid line pressure and temperature at the liquid
line near the filter-drier. The subcooling values should be between 6°F-20°F (6.6°C-11.1°C). The
subcooling values will be highest at 75-100% load, approximately 12°F-20°F (6.6°C-11.1°C) and
lowest at 50% load, approximately 6°F-12°F (3.3°C-6.6°C).
6. With outdoor temperatures above 60°F (15.6°C) all condenser fans should be operating and the
liquid line temperature should be within 5°F-10°F (2.8°C-5.6°C) of the outdoor air temperature. At
25-50% load the liquid line temperature should be within 5°F (2.8°C) of outdoor air temperature
with all fans on. At 75-100% load the liquid line temperature should be within 10°F (5.6°C) of
outdoor air temperature with all fans on.
7. Overcharging of refrigerant will raise the compressor discharge pressure due to filling of the
condenser tubes with excess refrigerant.