Water Quality And System Preparation; Water Pipe Work - Mitsubishi Electric EHSD-MEC Installation Manual

4
Installation

4.2 Water Quality and System Preparation

General
• The water in both primary and sanitary circuit should be clean and with pH value of 6.5-8.0.
• The followings are the maximum valves;
Calcium: 100mg/L, Ca hardness: 250mg/L
Chlorine: 100mg/L, Copper: 0.3mg/L
Iron/Manganese: 0.5mg/L
• Other constituents should be to European Directive 98/83 EC standards.l
• In known hard water areas, to prevent/minimise scaling, it is beneficial to restrict
the routine stored water temperature (DHW max. temp.) to 55°C.
Anti-Freeze
Anti-freeze solutions MUST use propylene glycol with a toxicity rating of Class 1 as
listed in Clinical Toxicology of Commercial Products, 5th Edition.
Note:
1. Ethylene glycol is toxic and must NOT be used in the primary water circuit
in case of any cross-contamination of the potable circuit.
2. For 2-zone valve ON/OFF control, propylene glycol MUST be used.
New Installation (primary water circuit)
• Before connecting outdoor unit, thoroughly cleanse pipework of building debris,
solder etc using a suitable chemical cleansing agent.
• Flush the system to remove chemical cleanser.
• For all packaged model systems, and the split model or PUMY system without
booster heater, add a combined inhibitor and anti-freeze solution to prevent
damage to the pipework and system components.
• For split model systems the responsible installer should decide if anti-freeze
solution is necessary for each site's conditions. Corrosion inhibitor however
should always be used.
Existing Installation (primary water circuit)
• Before connecting outdoor unit the existing heating circuit MUST be chemically
cleansed to remove existing debris from the heating circuit.
• Flush the system to remove chemical cleanser.
• For all packaged model systems add a combined inhibitor and anti-freeze
solution to prevent damage to the pipework and system components.
• For split model systems the responsible installer should decide if anti-freeze
solution is necessary for each site's conditions. Corrosion inhibitor however
should always be used.
When using chemical cleansers and inhibitors always follow manufacturer's
instructions and ensure the product is appropriate for the materials used in
the water circuit
How to access Internal Components and Control
and Electrical Box
<A> Opening the front panel
1. Remove the two lower screws.
2. Slide front panel upwards slightly and open carefully.
3. Disconnect the relay connector connecting main remote controller cable and the
control board cable.
<B> Accessing the back of the control and electrical box
The control and electrical box has a holding screw on the right and is hinged on
the left hand side.
1. Remove the holding screws on the control and electrical box.
2. The control and electrical box can then be swung forward on the left hand hinges.
Note:
1. Before accessing back of control and electrical box release cables from the
tie straps attached to the cross-support.
2. After servicing, re-secure all cables using straps provided. Reconnect
main remote controller cable to its relay connector. Replace front panel
and re-secure screws at base.

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 (local supply) at the water intake ("Pipe E" in
Table 3.3, also see associated schematic Fig. 3.5)
Minimum amount of water required in the space
heating / cooling circuit
Outdoor heat pump unit
Packaged model PUHZ-W50
PUHZ-W85
PUHZ-W112
PUHZ-HW112
PUHZ-HW140
Split model SUHZ-SW45
PUHZ-SW40
PUHZ-SW50
PUHZ-FRP71
PUHZ-SW75
PUHZ-SW100
PUHZ-SW120
PUHZ-SHW80
PUHZ-SHW112
PUHZ-SHW140
PUMY-P112
PUMY-P125
PUMY-P140
<Table 4.2.1>
Note:
For 2-zone temperature control system, the value in the table above
excludes the amount of stored water in zone2.
<A>
Hinges
Screws
<Figure 4.2.1>
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.
Minimum water quantity [L]
29
37
48
48
60
17
17
22
32
32
43
54
34
48
60
80
80
80
<B>
Screws
Open
12