Caution
Circulating Fluid
Tap Water (as a Circulating Fluid) Quality Standards
The Japan Refrigeration and Air Conditioning Industry Association
JRA GL-02-1994 “Cooling water system – Circulating type – Make-up water”
Warning
Maintenance
15. The tank capacity is approx. 110 mL. When the
fl uid level goes below the Low level, “ERR20” (Low
fl uid level alarm) will be triggered.
1. Prevention of electric shocks and fire
Do not operate the switch with wet hands. Also, do not operate
the thermo-con when water is present on its exterior surface.
2. Action in the case of error
If any error such as an abnormal sound, smoke, or bad odor
occurs, cut off the power at once, and stop supplying and
conveying fluid. Please contact SMC or a sales distributor to
repair the thermo-con.
3. Regular inspection
Check the following items at least once a month. The
inspection must be done by an operator who has sufficient
knowledge and experience.
a) Check the displayed contents.
b) Check the temperature, vibration level, and for abnormal
sounds in the body of the thermo-con.
c) Check the voltage and current of the power supply system.
d) Check the circulating fluid for leakage, contamination, and
the presence of foreign matter. Replace the fluid when
necessary.
e) Check the flow condition and temperature of the radiated
air.
∗
1 In the case of [M
Ω
폷
c m], it will be 0.003 to 0.01.
폷
쑗
: Factors that have an effect on corrosion or scale generation
폷
Even if the water quality standards are met, complete prevention of corrosion
is not guaranteed.
Item
Unit
Standard value
Influence
Corrosion
Scale
generation
Standard item
pH (at 25
°
C)
—
6.0 to 8.0
쑗
쑗
Electric conductivity (25
°
C) [µS/cm]
100
∗
1
to 300
∗
1
쑗
쑗
Chloride ion (Cl
–
)
[mg/L]
50 or less
쑗
Sulfuric acid ion (SO
4
2–
)
[mg/L]
50 or less
쑗
Acid consumption amount (at pH4.8)
[mg/L]
50 or less
쑗
Total hardness
[mg/L]
70 or less
쑗
Calcium hardness (CaCO
3
) [mg/L]
50 or less
쑗
Ionic state silica (SiO
2
)
[mg/L]
30 or less
쑗
Reference item
Iron (Fe)
[mg/L]
0.3 or less
쑗
쑗
Copper (Cu)
[mg/L]
0.1 or less
쑗
Sulfide ion (S
2
–
)
[mg/L]
Should not be detected.
쑗
Ammonium ion (NH
4
+
)
[mg/L]
0.1 or less
쑗
Residual chlorine (Cl)
[mg/L]
0.3 or less
쑗
Free carbon (CO
2
)
[mg/L]
4.0 or less
쑗
11. If there is a point where fluid is released to
atmosphere externally (tank or piping), minimise
the piping resistance at the circulating fluid return
side.
If the piping resistance is too large, the piping may be crushed
or the built-in circulator tank may be deformed or cracked
because the pressure in the piping for return will become
negative. The built-in circulator tank is made of resin (PE).
Therefore, the tank may be crushed if the pressure is negative.
Special attention must be paid if the flow rate of the circulating
fluid is high. To avoid a negative pressure of -0.02 MPa or
below, the piping return should be as thick and short as
possible to minimise piping resistance. It is also effective to
restrict the flow rate of circulating fluid or remove the gasket of
the internal tank for the release to atmosphere.
12. Fluorinated fluid falls outside of the specifications.
If it is used in the thermo-con, static electricity will be generated
by the flow of fluid. This static electricity may be discharged to
the board of the thermo-con, causing damage, operation
failure, or loss of data such as set temperatures.
Also, as the specific gravity of the fluorinated fluid is 1.5 to 1.8
times that of water, the pump will be overloaded, which also
causes fluorinated fluid to fall outside the specifications.
Therefore, if fluorinated fluid is to be used, please contact SMC
and we will introduce you to other suitable products (water-
cooled type).
13. Avoid operation with cavitation or bubbles due to low
fluid level in the tank. This may shorten the pump life.
14. If tap water is used, it should satisfy the quality
standards shown below.
HEF
Series
Specific Product Precautions
Be sure to read this before handling the products. Refer to the back cover for safety instructions.
For temperature control equipment precautions, refer to the “Handling Precautions for SMC
Products” and the “Operation Manual” on the SMC website: https://www.smc.eu
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