Unit installation

40 IOMM ACZ/AGZ
Startup
Pre Start-up
The system components must be inspected to ensure that nothing has became loose or damaged
during shipping or installation.
Start-Up
For AGZ-AM units refer to the Global UNT Controller or MicroTech Controller sections to become
familiar with the operation before starting chiller.
For ACZ units, the field furnished and installed capacity control system should be thoroughly
understood prior to starting the unit.
There should be adequate building load (25% of unit capacity minimum) to properly check the
operation of the system’s refrigerant circuits.
Be prepared to record all operating parameters required by the “Compressorized Equipment
Warranty Form”. Return this information within 10 working days to McQuay International as
instructed on the form to obtain full warranty benefits.
1. Verify chilled water flow or air flow for DX coil.
2. Verify remote start / stop or time clock has requested the chiller to start.
3. For UNT control, set the chilled water or leaving air control setpoint to required temperature.
(The system water temperature must be greater than the total of the leaving water temperature
setpoint plus 1/2 the control band before the Global UNT controller will stage on cooling.)
4. Set the control band to 4°F as a starting point.
5. Put both circuit switches to the AUTO position.
6. Put switch S1 to AUTO position.
7. There will be a delay of 2 minutes after closing S1. The time delay is due to the compressor
inherent motor protection. This may allow more than one compressor to start after this time
period. This should only occur on initial start-up or when power to the chiller has been turned
off and back on. The panel Alarm Light will turn off.
8. After the system has been operating for a period of time and has become stable, check the
following:
§ Compressor oil level. (Some Scroll compressors do not have oil sight glasses)
§ Refrigerant sight glass for flashing.
§ Rotation of condenser fans.
9. Complete the “Compressorized Equipment Warranty Form”.
Shutdown
Temporary
1. Put both circuit switches to Pumpdown and Stop.
2. After compressors have stopped, put System Switch (S1) to Emergency Stop.
3. Turn off chilled water pump on water chilling applications. Chilled water pump to operate
while compressors are pumping down.
To start the chiller after a temporary shutdown follow the start up instructions.