Safety Device Connections; Piping Diagram Of 2-Zone Temperature Control - Mitsubishi Electric ecodan EHPX-Serie Installationshandbuch

4
Installation
Water Circulation Pump Characteristics
EHSC, ERSC series
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
0.0 5.0 10.0 15.0 20.0 25.0
Flow rate [L/min]
<Figure 4.3.4>
EHPX series * (with PUHZ-W50)
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
0.0 5.0 10.0 15.0 20.0 25.0
Flow rate [L/min]
<Figure 4.3.5>
* For installation of EHPX series, set its pump speed with a pressure drop between the hydrobox and the outdoor unit factored into the external static pressure.

Safety Device Connections

The hydrobox contains a pressure relief valve. (see <Figure 4.3.8>) The con-
nection size is G1/2" female. The installer MUST connect appropriate discharge
pipework from this valve in accordance with local and national regulations.
Failure to do so will result in discharge from the pressure relief valve directly into
the hydrobox and cause serious damage to the product.
All pipework used should be capable of withstanding discharge of hot water.
Relief valves should NOT be used for any other purpose, and their discharges
should terminate in a safe and appropriate manner in accordance with local regu-
lation requirements.
Note: Beware that the manometer and the pressure relief valve are NOT
strained on its capillary side and on its inlet side respectively.
If a pressure relief valve is added, it is essential that no check valve
or isolation valve is fitted between the hydrobox connection and the
added pressure relief valve (safety matter).
Piping diagram for 2-zone temperature control
The following component parts are required for piping for 2-zone control opera-
tion.
Arrange the following component parts.
• Mixing tank (field supply)
• Motorized mixing valve (field supply)
• Water circulation pump (× 2) (field supply)
• Flow switch (× 2) (field supply)
• Thermistor (× 4) *2 sets of (PAC-TH011-E) thersmistors are required.
Wire the component parts to the water circuit referring to <Figure 4.3.9.>.
For more details on wiring, refer to "5.3 Wiring for 2-zone temperature controls".
Note: Do not install the thermistors on the mixing tank. This could affect
correct monitoring of flow and return temperatures through each
zone.
Install the Zone2 flow temp. thermistor (THW8) near the mixing valve.
21
Speed 5 (Default)
Speed 4
Speed 3
Speed 2
Speed 1
30.0 35.0 40.0
EHPX series * (with PUHZ-W85)
80.0
Speed 5 (Default)
70.0
Speed 4
Speed 3 60.0
Speed 2
50.0
Speed 1
40.0
30.0
20.0
10.0
0.0
30.0 35.0 40.0 0.0 5.0
Speed 5 (Default)
Speed 4
Speed 3
Speed 2
Speed 1
10.0 15.0 20.0 25.0 30.0 35.0 40.0
Flow rate [L/min]
<Figure 4.3.6>
Motorized
mixing valve
Mixing tank
Thermistor (THW6): Zone1 flow temp.
Thermistor (THW7): Zone1 return temp.
Thermistor (THW8): Zone2 flow temp.
Thermistor (THW9): Zone2 return temp.
EHPX series * (with PUHZ-HW112/140)
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
0.0 5.0 10.0 15.0 20.0 25.0
Flow rate [L/min]
<Figure 4.3.7>
Factory-fitted pressure relief valve
(G1/2" female connection)
Discharge to drain
(pipe MUST be fitted by installer).
<Figure 4.3.8>
Water circulation pump 2
(Zone1)
THW6
THW7
Flow switch 2 (Zone1)
Water circulation pump 3
(Zone2)
THW8
THW9
Flow switch 3 (Zone2)
<Figure 4.3.9>
Speed 5 (Default)
Speed 4
Speed 3
Speed 2
Speed 1
30.0 35.0 40.0
Heat emitters (Zone1)
Heat emitters (Zone2)