Nilfisk SR 1450 B Manuel D'utilisation page 104

ENGLISH
Drive direct current motor (SR 1450 B)
Maintenance
Ensure that the surface along which the carbon
brushes slide is covered with an even, shiny, transpar-
ent light grey fi lm.
Check that there are no black marks or burns between
the commutator segments and on the commutator
outer crown.
Ensure that the commutator surface is not lined, deep-
ly grooved or burnt on the segment in or out edges.
Manifold block Check that the brooms have not grooved the com-
mutator surface and that the insulating mica does not
protrude from the copper segment.
Check that the commutator is clean and that there
are no burns on the segments; if necessary, clean the
commutator as described.
Check eccentricity
Clean the commutator with special rubber sticks. If
necessary, clean between the segments.
Check the carbon brush for wear. It is worn out when
more than half of its total length has been consumed.
Check that it slides freely in the brush holder, that it is
pressed correctly by the spring and that the spring is
still elastic.
Ensure that the surface along which the carbon
brushes slide is evenly and highly polished and that
any lines or porosity are extremely small and of similar
dimensions.
Check the wire for wear and ensure that the connec-
tion terminals are well tightened.
Brooms
Ensure that there are no big lines, deep grooves, cra-
ters, burns or splinters on the carbon brush edge and
that all the carbon brushes are worn in the same way.
Check the housing for wear and clearance. Brushes
usually last from 6 months to 1 year, depending on
use.
Check the carbon brush and coupling pressure.
When the warning light turns on, the carbon brushes
need to be replaced, even if 300 hours have not been
reached.
Check that supply bolt nuts are well tightened and that
Terminals
the insulating materials are in good condition.
Ensure that air intakes are not clogged and that the
Fan
fan turns freely.
Check the temperature and the vibration and noise
Bearings
degree.
Use a megger, especially when the environment is
Insulation wet, to check the insulation value: it should never be
less than 2 MOhm.
Check that the screws are not loose.
Screws
Check that there are no faulty contacts in the electrical
connections which could lead to local overheating.
General cleaning. Check that the insulation to ground
Windings
is less than 2 MOhm.
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USER MANUAL
33014811(3)2010-03 A
Every Every Every
150 200 400
hours hours hours
SR 1450 B-D
Every 6 Every Every time a check
months year is carried out