Unit installation

803 C – 01/05 A – pag. 15/17
Charging the refrigerant
1. Connect the refrigerant bottle with a filling pipe to the filling valveon the evaporator head. Before firmly
tightening the refrigerant botlle valve, open it and force the air out from the filling pipe. Tighten the charcing
valve connection.
2. When the refrigerant stops to enter the system, start the compressor and complete the refrigerant charge.
3. When the exact quantity of refrigerant has been predetermined, check the liquid sight glass.
If you do not know how much refrigerant has to be added, shut off the bottle valve every 5 minutes and continue to
charge the refrigerant until the sight glass is clear and free from bubbles.
Note: Do not discharge the refrigerant into the atmosphere. To recover it, use empty, clean and dry bottles. The
liquid refrigerant recovery can be made through the valve provided on the condenser coil subcooler outlet. To
facilitate the recovery of refrigerant, put the bottle inside a container full of ice; avoid excessive filling of the bottle
(70÷80% max).
Start-up and shut-down
Pre-Start-up
1. Open all electrical disconnects and check electrical connections are tight.
2. Verify water piping flow directions are correct and properly connected at the evaporator and condenser.
3. Using a phase tester, verify electrical phasing is A-B-C clockwise (A=L1, B=L2,C=L3).
4. Verify unit power supply is within 10% of nameplate rating.
5. Verify power supply wiring is the correct size and has a minimum temperature insulation rating of 75°C.
6. Verify all mechanical and electrical inspections have been completed according to local code.
7. Make certain all auxilliary control equipment is operative and an adequate cooling load is available.
8. Check all compressor valve connections for tightness.
9. Open compressor suction valve until backseated.
10. Open discharge shutoff valve until backseated.
11. Vent air from the evaporator and condenser water system piping.
12. Open all water flow valves and start chilled water pump.
13. Check all piping for leaks.
14. Flush the evaporator and condenser system piping.
Initial Start-up
Initial Start-up must be performed by McQuayService personnel.
1. Set up control as described in Initial Conditions.
2. Turn front panel switch to Auto position. (chilled water flow pump relay will energize.)
3. If the field installed flow indicator does not indicated chilled water flow after 30 seconds, then the alarm
output will be energized.
Note: The unit starts the compressor with the least starts and run hours while in auto lead lag setting
4. When the Active Setpoint is 3 °C lower than the actual leaving water temperature, the chiller starts.
5. When the chiller starts the following occurs:
• Crank case heaters de-energize
• Compressor starts
• Motor cooling solenoid is energized
6. Suction injection will turn off when the following conditions have been met:
• Discharge superheat drops below 3 °C
• Liquid Presence sensor shows liquid