Water Pipework - Mitsubishi Electric ecodan EHPT20Q-VM2EA Installation Manual

4
Installation
How to access Internal Components and Control and Electrical Box
<A> <B>
screws
Front panel
Open
Hinges
screws
<Figure 4.2.1>
Note:
After servicing, re-assemble and re-secure all cables using straps provided. Reconnect
main controller cable to its relay connector. Replace front panel and re-secure screws at
base.
Minimum amount of water required in the space heating circuit
32 L
Note: The volume of heat emitters and external pipes should be included.
Reference:
Minimum water quantity [L]
Primary circuit Thermal store tank 200 L
Space heating circuit 32 L
Secondary (potable) circuit 2 L
<Table 4.2.1>
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<A> Opening the front panel
1. Remove the fi ve screws.
2. Slide front panel downwards slightly and open carefully.
3. Disconnect the relay connector connecting main
controller cable and the control board cable using the
quick-connector.
<B> Accessing the back of control and electrical box
The control and electrical box has four holding screws and
is hinged on the right hand side.
1. Remove the holding screws on the control and electrical
box.
2. The control and electrical box can then be swung
opened / closed on the right hand hinges.
4
Installation

4.3 Water Pipework

Hot Water Pipework
The cylinder unit is UNVENTED. When installing unvented indirect hot water systems building
regulations part G3 (England and Wales), P3 (Scotland) and P5 (Northern Ireland) should be
adhered to. If outside of the UK please adhere to your own country's regulations for unvented
hot water systems.
Connect the fl ow for the DHW to pipe A (Figure 3.1). The function of the following safety components of the system
should be checked on installation for any abnormalities;
• Pressure relief valve (Primary circuit)
• Primary expansion vessel pre-charge / gas charge pressure (Accessory item)
The instruction on the following pages regarding safe discharge of hot water from Safety devices should be followed
carefully.
• The pipework will become very hot, so should be insulated to prevent burns.
• When connecting pipework, ensure that no foreign objects such as dirt or debris enter the pipe.
Cold Water Pipework
Cold water to the suitable standard (see section 4.2) should be introduced to the system by connecting pipe B
(Figure 3.1) using appropriate fi ttings.
Negative pressure prevention
To prevent negative pressure effecting water circuit, installer should install pipework or use appropriate devices.
Hydraulic fi lter work
Install a hydraulic fi lter or strainer (local supply) at the water intake ("Pipe E" in Fig.3.1)
Pipework Connections
Connections to the cylinder unit should be made using the 22 mm compression as appropriate.
Do not over-tighten compression fi ttings as this will lead to deformation of the delivering and potential leaks.
Note: To weld the pipes in the fi eld, ensure the pipes on the cylinder unit are cooled using
wet towel etc.
Insulation of Pipework
• All exposed water pipework should be insulated to prevent unnecessary heat loss and condensation. To prevent
condensate entering the cylinder unit, the pipework and connections at the top of the cylinder unit should be
carefully insulated.
• Cold and hot water pipework should not be run close together where possible, to avoid unwanted heat transfer.
• Pipework between outdoor heat pump unit and cylinder unit should be insulated with suitable pipe insulation
material with a thermal conductivity of ≤ 0.04 W/m ˙ K.
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