VARISCO V 100-2, Operating Manual, Page: 16 / 36

Page 16
4.2.2 Nameplate
The data on the nameplate relates to a final acceptance with oil at 20°C and a viscosity of 100 cSt.
4.2.3
II 2 G C X
See below
Protection by constructional safety to EN 13463-5
Use in atmospheres with gas/vapour/mist
Category 2
Group II
As the actual maximum surface temperature varies with the temperature of the pumped fluid rather than
the ignition sources, no marking is made to show a temperature class or temperature. The marking
includes the symbol "X" and reference to surface temperatures occurring is made in Section 2.9.6 of this
Operating Manual.
4.3 Main components
4.3.1 Magnetic coupling
The external rotor is driven by an electric motor through antifriction
bearings. It is due to the magnetic forces of the permanent magnets
that the internal rotor is driven in synchronism with the motor
speed. The rotating magnetic field induces in the containment shell
eddy currents attributable to the conductivity of the latter. Hence,
there is a heat build-up in the containment shell. In the hydraulic
section, part of the pumped fluid is branched off through ports in the
rear casing cover, to pass through the inside of the containment
shell and return through a shaft bore, thereby dissipating heat. The
hydrodynamic plain journal bearings are lubricated by the pumped
fluid present in the containment shell.