Water System Diagram - Mitsubishi Electric EHPT17X-VM2E Service Manual

8

WATER SYSTEM DIAGRAM

<E*PT17X-*M*E> (Packaged model system)
Note:
Do not attach an
additional pressure
relief valve to the Drain
heating (cooling)
circuit on E*PT**X
model to keep fire
safety.
31
3
34 41 *b
34
37 36
<EHPT20X-MEHEW> (UK model system) <Example>
10
Note:
Do not attach an
additional pressure
relief valve to the
heating (cooling)
32
circuit on E*PT**X
model to keep fire
safety.
Drain
31
3
41*b
34
34
36
37
OCH814A
Cold water
33
36
32
21
9
A
10
7
Pa
15
18
26
27
17
19
16
5
22
23
6
42
24
4
6
14 25
11
13
12
6
Cylinder unit
<Figure 8.1>
40
38
Cold water
36
A
32
9
Drain
7
20
Pa
15
18
26
27
17
16
19
5
22
23
6
24
6
25
14
11
13 12
6
Cylinder unit
<Figure 8.2>
Water flow
DHW
B
34
Local system
*a
35
34
33
Water
Drain
supply
Water flow
DHW
B
34
Local system
*a
35
34
Drain
Flexible hose
(Temporary connection)
39
Mains water supply
30
*a. Refer to the following section [Local system].
*b. If the outdoor unit is higher than the indoor
unit, or if there is a location where air gets
trapped in the upper part of the water pipe,
consider adding this part.
Notes
• To enable draining of the cylinder unit, an
isolating valve should be positioned on
both the inlet and outlet pipework.
• Be sure to install a strainer on the inlet
pipework to the cylinder unit.
• Suitable drain pipework should be attached
to all relief valves in accordance with your
country's regulations.
• A backflow prevention device must be in-
stalled on the cold water supply pipework
(IEC 61770)
• When using components made from dif-
ferent metals or connecting pipes made
of different metals, insulate the joints to
prevent any corrosive reaction taking place
which may damage the pipework.)
*a. Refer to the following section 'Local sys-
tem' on the 'Paper-based manual'.
Note
• To enable draining of the cylinder unit, an iso-
lating valve should be positioned on both the
inlet and outlet pipework. No valve should be
fitted between the expansion valve (item 38)
and the cylinder unit (safety matter).
• For space heating (primary) circuit, a suit-
able expansion vessel MUST be supplied
and fitted by installer.
• Be sure to install a strainer on the inlet pipe-
work to the cylinder unit.
• Suitable drain pipework should be attached
to all relief valves in accordance with your
country's regulations.
• When using components made from differ-
ent metals or connecting pipes made of dif-
ferent metals, insulate the joints to prevent
any corrosive reaction taking place which
may damage any pipework.
• Filling loop's flexible hose must be removed
following the filling procedure. Item provided
with unit as loose accessory.
• Install the inlet control group (item 38)
above the level of the T&P relief valve (item
20). This will ensure DHW tank will not
require drain down to service/maintain the
inlet control group.