9InRow RD 10 kW Air Cooled Operation and Maintenance
Charging the equipment
Caution: This procedure is to be done by APC-trained personnel only.
R410A is a blend refrigerant. When charging equipment with blend refrigerants, only liquid refrigerant
must be charged.
Caution: Charging with other than liquid R410A refrigerant may damage the system.
1. Ensure the ball valves are open.
2. Confirm the calculated system charge.
3. Connect the refrigerant cylinder to the charging or gauge port on the receiver outlet valve. Open
the receiver valve approximately half way.
4. Charge liquid refrigerant into the high side of the system until the system pressures equalize.
While the unit is NOT operational, charge liquid to the suction (low side) line to simply equalize
pressures throughout the system DO NOT start the system until the pressure equalizes. Please
note charging liquid to the suction port during operation may damage or reduce the life of the
compressor.
5. Prior to starting the system, make sure all system valves are open and the system high side
pressure remains above 24.8 bar (360 psi). This may require blocking the condenser inlet slightly.
Remove any blocking panels after charging is complete.
6. Start the cooling unit. See “Start the cooling unit” on page15 for more information.
7. Once the system is operational, front seat the receiver service valve and continue charging liquid
at the Schrader port down stream of the receiver shutoff valve, until the calculated charge is
complete. When this procedure is complete, fully back seat the receiver shutoff valve. Leave
charging hoses in place in the event additional charging is required.
8. Charge the rest of the calculated liquid refrigerant very slowly through the suction port.
9. Verify that the sightglass is clear. If there is excessive bubbling in the sightglass, make sure the
system high side pressure is above 23.4 bar (340 psi) and Superheat and Subcooling are within
parameters (10-12 for Superheat and 8-10 for Subcooling). If additional charging is required,
front seat the receiver shutoff valve and weigh in the additional charge at the Schrader port.
Note: Since good performance during low ambient temperatures depends on proper
refrigerant charge, it is very important that this phase of the installation procedure be
done carefully. Poor system performance can be due to too little or too much charge.
Caution: Fast charge of liquid refrigerant through the suction
port may damage the compressor.