Vertiv Liebert DME22 - Start-up Commissioning and Function Testing

Vertiv | Liebert® DM | User Manual 64
Start-up Commissioning
The inspection requirements after starting-up are listed in Table 4-2.
Table 4-2 Component Inspection after Starting-up
Components Inspection Requirements
Fan
• Check if the rotation direction of the blades is correct.
• Check and record the rated full load current and actual current of the fan motor.
Electrical Heater
(if applicable)
• Record the electrical heater current.
Outdoor fan
• Check if the rotation direction of the blades is correct.
• Check and record the rated full load current and actual current of the fan motor.
Refrigerant charge
amount
• Check after the compressor is turned On, if the refrigerant (R410A) is dynamically
charged until there is no air bubble in sight glass. The condensation and sub-cooling
temperature reaches 3 K or more, while the suction superheat temperature reaches 7 K
or more.
• Observe the compressor suction line to ensure that the piping and compressor housing
are free of condensation to avoid potential damages caused by liquid presence.
• Check if the unit exhaust superheat is in the range of 25 °C to 50 °C.
Others
• Record user setpoint values, return air temperature, suction pressure, exhaust pressure,
compressor current, and outlet air temperature.
• During the dynamic charging of the air conditioning unit, the liquid refrigerant should be slowly charged
into the system from the compressor air return piping to prevent the compressor from being exposed to
liquid that can impact hazard on the system.
• The refrigerant should not be overcharged. The recommended amount of refrigerant (kg) is represented
in Table 2-12.
4.2. Function Testing
The lethal voltage may be present in the unit which can be fatal, therefore cut o the power supply prior to
functional testing. All notes, warnings, and cautions marked on the unit as well as the ones mentioned in the
manual must be considered, otherwise, it may lead to injury and fatality.
Only qualified service and maintenance personnel can perform system operation and maintenance.
4.2.1. Cooling
Adjust the temperature setpoint to 5 °C (10 °F) lower than the indoor temperature. Then the control system triggers the
cooling demand signal and the compressor starts to work. After at least 3 minutes of cooling, adjust the temperature
setpoint to 5 °C (10 °F) higher than the indoor temperature. If the compressor stops working, it means that the cooling
function is normal. Refer Section 5.4.3 (Temp/Hum) for better understanding.