WEGeuro - Indústria Eléctrica, S.A. Português - English
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8.5 Periodically inspect the motor functioning according to its application ensuring a free
flow of air. Inspect the seals, the fixing screws, the bearings vibration and noise levels,
the draining devices, etc.
8.6 Motors which may have a potential risk of electrostatic charge accumulation, supplied
duly identified with a warning plate, must receive proper cleaning and maintenance
interventions, e.g. with the use of a damp cloth, avoiding electrostatic discharges.
8.7 The maintenance of flameproof motors is particularly important, as:
Any changing to the bearings could:
o cause a sudden temperature rise, thus presenting a risk of explosion
o increase the clearance between the shaft and the bearing plate, due to
friction of the shaft on the closing plate; an internal ignition may spread to
the outside and can cause an explosion
Concerning external ventilation, a fault in the cooling system raises the surface
temperature, which could reach values higher than those established for the
temperature class.
The temperature class should be checked on the certification plate; this
indicates the maximum temperature as follows:
T3 or T4 or T135ºC or T125ºC
8.8 All explosion-proof motors are supplied with an anti-corrosion product in the fittings
and screws. Before assembling the components with machined surfaces (for example,
terminal box covers of flameproof motors) machined surfaces must be cleaned and a
new protective layer of this product shall be applied.
To protect the surface of flameproof joints one of the following protective greases
recommended by WEG shall be used: Polyrex EM (manufacturer Mobil) or Lumomoly
PT/4 (manufacturer Lumobras) for a temperature ambient range from -20°C to +80°C,
Molykote 33 (manufacturer Dow Corning) for a temperature ambient range of -55°C to
+80°C.
8.9 For explosion-proof motors care shall be taken with the flamepath machined surfaces
in order to avoid the presence of burrs, scratches, etc., which reduce their flamepath
lenght and/or increase the flamepath gap.
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