Midea MC-SU30-RN1L Owners & Installation Manual page 14

4.8 Water quality control
4.8.1 Water quality control
When industrial water is used as chilled water, little furring may
occur; however, well water or river water, used as chilled water,
may cause much sediment, such as furring, sand, and so on.
Therefore, well water or river water must be filtered and softened
in softening water equipment before flowing into chilled water
system. If sand and clay settle in the evaporator, circulation of
chilled water may be blocked, and thus leading to freezing
accidents; if hardness of chilled water is too high, furring may
occur easily, and the devices may be corroded. Therefore, the
quality of chilled water should be analyzed before being used,
such as PH value, conductivity, concentration of chloride ion,
concentration of sulfide ion, and so on.
4.8.2 Applicable standard of water quality for the unit
Table 4-2
PH value
Total hardness
Conductivity
Sulfide ion
Chloride ion
Ammonia ion
Sulfate ion
Silicon
Iron content
Sodium ion
Calcium ion
I&O manual
10
7～8.5
<50ppm
<200μV/cm(25℃)
No
<50ppm
No
<50ppm
<30ppm
<0.3ppm
No requirement
<50ppm
4.9 Installation & regulation guide for target flow
controller
4.9.1 Please carefully check flow switches before conducting
installation of the target flow controller. Packing should be in
good condition, and the appearance should be free of damage
and deformation. If any problem, please contact the
manufacturer.
4.9.2 Flow switches can be installed in the horizontal pipeline or
the vertical pipeline with upward flowing direction but cannot be
mounted in the pipeline with downward flowing direction. The
inlet water of gravity should be taken into account when flow
switches are installed in the pipeline with upward flowing
direction.
4.9.3 Target flow controller must be installed on a section of
straight-line pipeline, and its both ends must be supplied with
straight-line pipes whose length is at least 5 times diameter of
the pipe. In the meanwhile, the fluid flowing direction in the
pipeline must be consistent with the direction of arrow on the
controller. The connection terminal should be located where
wiring connectioncan be easily done.
4.9.4 Pay attention to the following items when conducting
installation and wire connection:
a. Collision of the wrench with the soleplate of the flow switch is
prohibited, since such collision may cause deformation and
failure of the flow switch.
b. To avoid electric shock and damages to the devices, the
power supply should be cut off, when wires are connected or
adjustment is done.
c. When wiring connection is conducted, adjustment of other
screws except connection terminals of micro switches and
ground screws is prohibited. In the meanwhile, over great force
should not applied when wires of micro switches are connected,
otherwise micro switches may suffer displacement, thus leading
to failure of flow switches.
d. Special grounding screws should be used for earth
connection. Bolts should not be installed or removed at will;
otherwise flow switches may suffer deformation and failure.
e. Flow switches have been set at minimal flow value prior to
ex-factory. They should not be adjusted below the ex-factory
setting value, or they may suffer failure. After installing flow
switches, please press the flow switch lever several times to
check them. When the lever is found not to respond with
"clatter", rotate the screw in a clockwise direction, until "clatter"
occurs.
f. Be sure to determine the model of target slice according to
the rated flow of the unit, the diameter of the outlet pipe and the
adjustment range of the target slice of the flow switch. Besides,
the target slice should not contact with other restrictors in the
pipeline or on the inner wall of the pipeline, or the flow switch
cannot be reset normally.
4.9.5 Determine whether the flow switch and the system
connected with it are in good operation according to the
measured value by flow meter, namely, when the measured
value on flow meter is less than 60% of rated water flow of the
unit, the target flow controller should be cut off and observed for
3 working periods, and it should be covered with flow switch
shell timely.