Mitsubishi Electric ecodan EHPT20Q-VM2EA Installation Manual page 9

4
Installation
Filling the System (Primary Circuit)
Note: Make sure to turn OFF the booster heater power supply before fi lling the system
1. Check all connections including factory fi tted ones are tight.
2. Insulate pipework between cylinder unit and outdoor unit.
3. Open the automatic air vent to enable automatic air bleeding function.
4. Thoroughly clean and fl ush, system of all debris. (see section 4.2 for instruction.)
5. Fill primary heating circuit with water and suitable anti-freeze as necessary.
Always use a new fi lling loop with double check valve when fi lling the primary circuit to
avoid back fl ow contamination of water supply.
Do not use an old fi lling loop.
Do Not turn ON the system until the system is fully charged of water.
• Open the two manual air vents after fi lling the system (refer to the following section) .
• Anti-freeze should always be used for packaged model systems (see section 4.2 for instruction). Corrosion
inhibitor should be used in both split model and packaged model systems.
• 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 leakage is found, retighten the nut onto the connections.
7. Pressurise system to 1 bar with all the water in thermal store tank cold.
(If the system is pressurised with the water in thermal store tank hot, air inclusion in pump may be caused by the
pressure drop of the system that occurs if the hot water gets cold. )
8. Release all trapped air using air vents during and following heating period.
9. Top up with water as necessary. (If pressure is below 1 bar)
Note: • Automatic air vents MUST be installed at the highest point of the primary system. The slightest amount of air in the system can
reduce effi ciencies and even cause the cylinder unit to fault.
• Confi rm the following if the air cannot be discharged.
• Air discharging of radiators
• Air discharging from isolating valves
(If necessary, turn on the pump 1 using Manual operation (refer to page 35).)
IMPORTANT<Air discharging of pump A>
1. Attach the accessory rubber hose to the manual air vent above pump A to
prevent water from dripping on to the pump during the air bleeding operation.
2. Open the drain cock of the manual air vent and discharge the air.
3. Open a tap and confi rm that hot water is supplied after approximately 30 minutes
from the beginning of thermal store operation.
Note: If the air is not suffi ciently discharged, hot water is not
supplied and an error occurs. Continue to discharge the
air until smooth delivery of hot water.
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4
Installation
Sizing Primary Expansion Vessels
Primary expansion vessel volume MUST fi t the local system water volume.
To size an expansion vessel for the heating circuit the following formula and graph can be used.
ε × G
V =
P ¹ + 0.098
1 −
P ² + 0.098
Where;
V : Necessary expansion vessel volume [L]
ε : Water expansion coeffi cient
G : Total volume of water in the system [L]
P : Expansion vessel setting pressure [MPa]
1
P : Max pressure during operation [MPa]
2
Primary expansion vessel sizing
25
20
15
10
5
0
0 50 100
Manual
air vent
Pump A
Graph to the right is for the following values
ε : at 70 °C = 0.0229
P : 0.1 MPa
1
P : 0.3 MPa
2
*A 30% safety margin has been added.
150 200 250 300 350 400
System water volume [L]
<Figure 4.3.1>
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