● Limit the total paint coating thickness according to the explosion protection group:
● Limit the surface resistance of the paint used:
● Charge transfer limit
● Breakdown voltage ≤ 4 kV for explosion group III (dust only)
Suitability test of the paint system for hazardous areas
Proof is available for the electrostatic suitability with explosion-proof machines for the paint
systems ordered by default. Such evidence is not available for paint systems that are non-
standard or specifically requested by customers. Take into consideration that the provided
evidence is not valid for repaintings.
Maintaining terminal boxes
The machine is de-energized.
Checking the terminal box
● Terminal boxes must be regularly checked for tightness, undamaged insulation, and tight
● If dust or humidity have infiltrated the terminal box, this should be cleaned and dried
SIMOTICS TN Series N-compact 1LA8
Operating Instructions 05/2014
– IIA, IIB: Total paint coating thickness ≤ 2 mm
– IIC: Overall coating thickness ≤ 0.2 mm for motors of group II (gas)
– Surface resistance ≤ 1 GΩ for motors of groups II and III (gas and dust)
– 60 nC for Group I or Group IIA devices
– 30 nC for Group IIB devices
– 10 nC for Group IIC devices
– 200 nC for Group III devices
(particularly the insulators).
Check all the seals and sealing surfaces and address the cause of the leakiness.
9.1 Inspection and maintenance