Mitsubishi Electric EHSD-MED Service Manual page 21

Filling the System (Primary Circuit)
1. Check and charge expansion vessel.
2. Check all connections including factory fitted ones are tight.
3. Insulate pipe work between hydrobox and outdoor unit.
4. Thoroughly clean and flush, system of all debris. (Refer to 4.2 in the installation manual.)
5. Fill primary heating circuit with water and suitable anti-freeze and inhibitor as necessary. Always use a filling loop with double check valve when filling the
primary circuit to avoid back flow contamination of water supply.
•
Anti-freeze should always be used for package systems. It is the responsibility of the installer to decide if anti-freeze solution should be used in split systems
depending on each site's conditions. Corrosion inhibitor should be used in both split and package systems.
Figure below shows freezing temperature against anti-freeze concentration. This figure is an example for FERNOX ALPHI-11. For other anti-freeze, please refer
to relevant manual.
•
When connecting metal pipes of different materials, insulate the joints to prevent a corrosive reaction taking place which will damage the pipework.
6. Check for leakages. If leakages are found, retighten the screws on the connections.
7. Pressurise system to 1 bar.
8. Release all trapped air using air vents during and following heating period.
9. Top up with water as necessary. (If pressure falls below 1 bar)
10. After removing the air, automatic air vent MUST be closed.
5
0
−5
−10
−15
−20
−25
0 10 20
Anti-freeze concentration [%]
Draining the Hydrobox
WARNING: DRAINED WATER MAY BE VERY HOT
1. Before attempting to drain the hydrobox, isolate from the electrical supply to prevent booster heater burning out.
2. Isolate hydrobox from primary water circuit and drain water from hydrobox. Use a suitable heat resistant hose to assist in these operations.
3. Drain any remaining water from booster heater using fitted drain cock and hose, and the drain valve on the primary circuit to safely drain the unit.
4. After the hydrobox is drained, water remains in the following component parts. Drain water completely by checking the inside of the parts.
• Strainer (Remove the strainer cover.)
• Pressure relief valve (Operate the valve.)
OCH712C
30 40 50
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