9.1.7
Bolt grade
Check that all the screws for attaching the end shields, bearing covers, gland plates, and
terminal boxes are present and properly tightened. Replace damaged bolts with identical
bolts of a perfect quality.
9.1.8
Maintenance
9.1.8.1
Explosion protection for machines with flameproof enclosure
For explosion-protected machines with type of protection flameproof enclosure according to
IEC/EN 60079–0 and IEC/EN 60079–1, observe the following:
• Machined bearing and fitting surfaces on the following components must not be
reworked or painted:
– Stator frame
– End shields, bearing cover
– Motor shaft
– Gland plate
– Terminal box lower part, terminal box cover
– Gland plates for additional terminal boxes, where present
• Keep these surfaces clean and protect them against corrosion by applying a thin coating
of grease. It is not permissible that any seals are fitted between the surfaces that
guarantee that flame is not transmitted.
9.1.8.2
Explosion hazard due to increased surface temperature
Explosion hazard due to increased surface temperature
Components within the motor may be hotter than the maximum permissible surface
temperature for the enclosure. In an explosive atmosphere, dust can ignite and an explosion
occur. This can result in death, serious injury or material damage.
• Do not open the motor in an explosive and dusty atmosphere when it is still at normal
operating temperature.
• Allow the machine to cool down before opening it.
1MB..5/6 shaft height 71 ... 355
Operating Instructions, 10/2021, A5E41926185A
Shaft height
71 ... 355
9.1 Inspection and maintenance
Bolt grade for ambient temperature T
≥ -40 °C ... ≤ 60 °C
Standard
8.8
Maintenance
u
≥ -55 °C ... ≤ 60 °C
Stainless steel bolts
A2-70
A2-80
A4-70
A4-80
109