Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document.
Note: Even the most advanced machine translation cannot match the quality of professional translators.
Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Injecting Liquid Working Medium
Precautions
- Before injecting liquid working medium into the cabinet, check the tightness of the cabinet.
- Fill the product to be tested with about 600 kPa compressed air or nitrogen.
- After the pressure is stable for 10 minutes, preserve the pressure for 60 minutes and observe the data on the pressure gauge. The pressure drop should be less than or equal to 15 kPa.
- For details about how to inject liquid working medium, see the documents provided by the CDU manufacturer. This section is for reference only.
After liquid working medium is injected for a period of time, the water turns yellow, which does not affect the system.
Procedure
- Loosen the nut on the exhaust valve.Figure 3-51 Loosening the nut on the exhaust valve
- Ensure that the filling wand of the CDU is clean.
If the filling wand is polluted, use deionized water to clean it.
The external CDU has a filling wand. The built-in CDU does not have a filling wand.
- Insert the filling wand of the CDU into the chilled water container and connect the filling wand to the CDU fill quick connect couplings.
- Power on the CDU and ensure that the water flow is stable without leaks.
- Start the CDU, enter the automatic running mode, and start filling water. After the pressure reaches 1 bar, the CDU automatically stops filling water.
- The fill pump may stop filling water and display an alarm due to timeout. The filling continues after the alarm is cleared.
- Observe the water level in the water container. The level cannot be lower than the intake of the filling wand; otherwise, air enters the filling wand and the filling is affected.
- Check whether water leaks.
- Remove the filling wand and put it in a specified location. Fill the make-up container with water and connect it to the CDU fill quick connect couplings.
- After the air is exhausted and the system runs stably for one week, tighten the nut on the exhaust valve to turn it off.Figure 3-52 Tightening the exhaust valve nut
- After the system runs for 15 minutes, check the concentration of liquid working medium. If the effective concentration of liquid working medium does not meet the system design requirements, contact the supplier.
Liquid working medium requirements: Ethylene glycol, the effective concentration of which must be greater than 25% (the concentration refers to the volume concentration).
