Mitsubishi Electric MR-J4-10B(-RJ) Instruction Manual page 673

APPENDIX
App. 11.3.3 Specifications
(1) Special coating
Using the MR-J4 series in an atmosphere containing a corrosive gas may cause its corrosion with time,
resulting in a malfunction. For the printed circuit board of the servo amplifiers with a special coating
specification, a urethane coating agent is applied to some parts capable of being coated technically
(except LEDs, connectors, terminal blocks, etc.) to improve the resistance to corrosive gases. Use a
servo amplifier with a special coating specification specifically for applications susceptible to corrosive
gases, including tire manufacturing and water treatment. Although the special coating-specification
products have the improved resistance to corrosive gases, proper operations in environments
mentioned above are not guaranteed. Therefore, perform periodic inspections for any abnormality.
(2) Standard for corrosive gases
In IEC 60721-3-3, corrosive gases refer to sea salt, sulfur dioxide, hydrogen sulfide, chlorine, hydrogen
chloride, hydrogen fluoride, ammonia, ozone, and nitrogen oxides shown in the environmental
parameter column of the table below.
The table also shows the corrosive gas concentrations defined in IEC 60721-3-3, Class 3C2.
Environmental parameter
a) Sea salt
b) Sulfur dioxide
c) Hydrogen sulfide
d) Chlorine
e) Hydrogen chloride
f) Hydrogen fluoride
g) Ammonia
h) Ozone
i) Nitrogen oxides
The special coating-specification products have the improved corrosion resistance in environments with
corrosive gas concentrations conforming to IEC 60721-3-3, Class 3C2. We tested typical models and
confirmed that their corrosive gas resistance was improved, compared with the standard models.
Unit
Mean value
None
cm /m 0.11
3 3
cm 3 /m 3 0.071
cm /m 0.034
3 3
cm 3 /m 3 0.066
cm /m 0.012
3 3
cm 3 /m 3 1.4
cm /m 0.025
3 3
cm 3 /m 3 0.26
App. - 60
3C2
Maximum value
Salt mist
0.37
0.36
0.1
0.33
0.036
4.2
0.05
0.52