![background image](http://html1.mh-extra.com/html/midea/smk-d140hhn1-3/smk-d140hhn1-3_manual_1790921014.webp)
High Temperature Hydro Module
12
202003
Midea
VR
Hi
gh
T
em
per
at
ur
e Hy
dr
aul
ic
Mo
dule
6.5
General precautions about the Water System
Check the following items before continuing installation:
Max. hydraulic pressure: 10 bar
Max. water temperature: 80 °C
Install enough safety devices in the water loops to ensure that the hydraulic pressure does not exceed the
maximum operating pressure (10 bar).
Provide a drainage hole at all the low points of the system so that the water is completely drained from the water
system when you repair or maintain the unit. A drain valve has been installed at the water inlet to facilitate water
discharge from the unit's water system.
Ensure that you have provided a suitable water discharge pipe to the safety valve to prevent water from coming
into contact with any electrical part. A water discharge pipe has been provided with the unit.
You must deploy air outlets at all the high points of the system. The air outlets should be deployed at the places
where they can be easily maintained. A drain valve has been installed at the water outlet to facilitate air discharge
from the unit's water system.
Ensure that all the components installed on pipes on site can bear water pressure and water temperature.
You should use materials that are compatible with water and equipment in the system.
Anti-freezing protection of the water system:
Freezing may cause damage to the system. The ODU may be exposed to temperatures below 0 C. You must
prevent the system from freezing.
All the internal water systems are insulated to prevent heat loss. On site, pipes should be fitted with insulating
materials.
The unit is designed with an anti-freezing function. The unit uses a heat pump to prevent the entire system from
freezing. When the water temperature in the system decreases to a certain value, the unit will heat water. The
anti-freezing function will be disabled only when the water temperature rises to a certain value.
In the event of power failure, the anti-freezing function cannot protect the unit from freezing.
Using anti-freezing liquid in the water system is recommended, because power failure may happen when no one
is present.
Ensure that the water system is full of the ethylene glycol concentration provided in the following table, according
to the expected lowest outdoor temperature. When ethylene glycol is added to the system, device performance
will be affected. The following table lists the correction coefficients of the unit capacity, flow, and pressure drop
of the system.
Ethylene Glycol
Quality
of
Glycol %
Modification Coefficient
Freezing Point
in degree C
Cooling
Capacity
Modification
Power
Modification
Water
Resistance
Water
Flow
Modification
0
1.000
1.000
1.000
1.000
0.0000
10
0.984
0.998
1.118
1.019
-4.000
20
0.973
0.995
1.268
1.051
-9.000
30
0.965
0.992
1.482
1.092
-16.000
40
0.960
0.989
1.791
1.145
-23.000
50
0.950
0.983
2.100
1.200
-37.000