Water Pipe Work; Hot Water Pipework; Hydraulic Filter Work (Only Ehpt Series); Pipework Connections - Mitsubishi Electric ecodan EHPX-Serie Installationshandbuch

4
Installation

4.3 Water Pipe Work

Note: Prevent the field piping from straining the piping on the hydrobox by
fixing it to a wall or applying other methods.

Hot Water Pipework

The function of the following safety components of the hydrobox should be checked
on installation for any abnormalities;
• Pressure relief valve
• Expansion vessel pre-charge (gas charge pressure)
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 debris or the
like do not enter the pipe.
Hydraulic Filter Work (ONLY EHPX series)
Install a hydraulic filter or strainer (field supply) at the water intake ("Pipe B" in
Fig.3.5, also see associated schematic Fig.3.10)
Drain Pipework (ONLY ERSC series)
The drain pipe should be installed to drain condensing water in Cooling mode.
• Securely install the drain pipe to prevent leakage from the connection.
• Securely insulate the drain pipe to prevent water dripping from the field supplied
drain pipe.
• Install the drain pipe at a down slope of 1/100 or more.
• Do not place the drain pipe in drain channel where sulfuric gas exists.
• After installation, check that the drain pipe drains water properly from the outlet of
the pipe.
<Installation>
. Apply polyvinyl chloride type adhesive over the shaded surfaces inside of the
drain pipe and on the exterior of the drain socket as shown.
2. Insert the drain socket deeply into the drain pipe <Figure 4.3.1>.
Note: Securely support the field supplied drain pipe using pipe support to
avoid the drain pipe falling from the drain socket.
<Checking Drainage>
• Check that the drain pipe drains water properly from the outlet of the pipe.
• Check for no leakage from the connection.
Note: Always check drainage at installation regardless of season.
• Remove the front panel and pour water of 1 liter into the drain pan <Figure
4.3.2>.
Note: Pour water slowly into the drain pan so that water does not overflow
from the drain pan.

Filling the System (Primary Circuit)

Filling
1. Check all connections including factory fitted ones are tight.
2. Insulate pipework between hydrobox and outdoor unit.
3. Thoroughly clean and flush, system of all debris. (see section 4.2 for
instruction.)
4. Fill hydrobox with potable water. 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.
9

Pipework Connections

Connections to the hydrobox should be made using the 28 mm compression as
appropriate. (except for ERSC series)
Do not over-tighten compression fittings as this will lead to deformation of the olive
ring and potential leaks.
Note: To weld the pipes in the field, cool the pipes on the hydrobox using wet
towel etc.
ERSC series have G1 (male) thread connections.

Insulation of Pipework

• All exposed water pipework should be insulated to prevent unnecessary heat loss
and condensation. To prevent condensate entering the hydrobox, the pipework
and connections at the top of the hydrobox 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 hydrobox should be insulated
with suitable pipe insulation material with a thermal conductivity of ≤ 0.04 W/
m.K.
Drain socket
Apply polyvinyl chloride
type adhesive
Field supplied
drain pipe
(VP-20)
Do not pour water into these openings.
<Figure 4.3.2>
• Anti-freeze should always be used for packaged model systems (see
section 4.2 for instruction). It is the responsibility of the installer to decide
if anti-freeze solution should be used in split model systems depending
on each site's conditions. 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.
5. Check for leakages. If leakage is found, retighten the screws onto the
connections.
6. Pressurise system to  bar.
7. Release all trapped air using air vents during and following heating period.
8. Top up with water as necessary. (If pressure is below 1 bar)
<Figure 4.3.1>