Mitsubishi Electric EHWT17D-MHEDW, Data Book

Page: 106 / 131

1
Installation
Carefully follow these instructions and ensure that the installation conforms to UK Building Regulation G3 and the Water Supply
Regulations.
Unvented inlet control group (ICG)
Item Component
1 Pressure reducing valve
2 Manifold block (Including check valve)
3 22mm balanced cold water take-off
4 Pressure gauge port
5 3/4" connection for exp.vessel
6 Expansion relief valve
1
2
3 4
5
6
It is recommended that isolating valves are installed upstream and downstream to facilitate any future maintenance.
For safety reasons, it is essential that no isolation valve is fitted between the ICG and the cold water inlet connection of the cylinder.
Install the pressure reducing valve with its embossed arrow pointing in the direction of flow.
Ensure the expansion relief valve is seated correctly into the main block/ casting and its nut is fully tightened to secure its position.
Ensure that the expansion relief valve discharge pipework has a continuous fall and terminates via a tundish and in such a posi-
tion as not to cause injury.
The first 22mm connection (Item 3 above) can be used to provide an unbalanced cold water supply. It must never be used to
connect the expansion vessel. If not used, use the blanking cap (22mm) supplied.
The small black plug is a connection prepared for a pressure gauge, which is available when specified.
On the opposite side of the manifold to the pressure gauge connection, there is a 3/4" plastic plugged connection that may be
used for direct mounting to the expansion vessel if required.
Expansion vessel
Tundish
Filling loop
Double check &
ball valve
Flexible hose
Ball valve
Ball valve Ball valve
Mains water supply
(Sanitary circuit)
Inlet from space heating
(Primary circuit)
Check
valve
Flexible hose
(Temporary)
Cylinder unit
Install the expansion vessel between the pressure reducing valve and the cylinder unit or by using the appropriate port of the
ICG. (Ensure the expansion vessel is connected to an active section of the potable pipework and is NOT directly connected to
any redundant “Dead-leg” section of pipework.)
Note:
■ When connecting the ICG to the expansion vessel using a field-supplied flexible hose, provide sufficient bending radius to
prevent abnormal noise.
■ For more details about the following instructions, refer to the installation manual provided with the potable expansion vessel,
as well as this manual.
• If the expansion vessel is installed separately to the ICG (ie. direct in-line) then the supplied flow diverter can be used.
• ICG should always be installed on cold water supply to cylinder to comply with WRAS/Building Regulation G3.
• The ICG. should be installed above the level of the T&P valve. This will avoid the requirement to drain cylinder when
servicing the ICG in future.
• Expansion vessel should be installed hanging from connecting pipework.
• Expansion vessel should be fastened to a suitable surface (wall etc.) to prevent strain on pipe connection.
• Gas inlet screw type of expansion vessel: 8V1
Install the tundishes in accordance with the UK Building Regulation G3. For more details refer to the "Safety Device Discharge
Arrangements" section in the installation manual for the cylinder unit .
Note: Refer to the installation manual provided with the filling loop as well.
Optional parts
D-35
EHPT Accessories for UK
4
Optional parts