General note
Attention should be paid to the information
contained in all operating and other instructions
supplied.
This is indispensable to avoid danger and risks of damage.
Additional safety information (yellow) including supplementary data on
the safety of electrical equipment is enclosed. These safety instructions
therefore also supplement all further operating and other instructions
supplied.
Moreover, the applicable national, local and plant-specific
regulations and requirements should be taken into account.
Special designs and type versions might differ in the technical
details. If there are any problems, it is strongly recommended to
contact the manufacturer stating the type designation and serial
number, or have repairs carried out by one of the Siemens service
centers.
Description
Application
The direct-current tachogenerator is used to measure the actual value of
the speed of single and multiple-quadrant drives. It is attached to the non-
drive end of electrical machines without a separate coupling.
Mode of operation, construction
The tachogenerator is in accordance with VDE specifications. The
tachogenerator has a stationary permanent-magnet field system. The
tachogenerator rotor produces a direct voltage, the polarity of which is
dependent on the direction of rotation.
A silver track is embedded in the tachocommutator for increasing the
commutator and brush lives.
When the main machine is running on load, a
voltage is present at the terminals or the
winding ends of the tachogenerator.
Technical data
(s. Fig. 5)
Maintenance
Checks: Inspect the brush and commutator condition during the
maintenance of the main machine (after 3000 to 5000 h). Maximum
service life of brushes is up to approx. 20,000-30,000 h at 1000 rev/m.
Brush replacement: Replace the brushes (see Fig.4). Clean the brush-
gear and the commutator of carbon dust. Clean the tachogenerator with
compressed air, insert the new brushes (8.90).
The nose (N), which is bent outwards and fitted on the brush-contact
stirrup, must engage in the slot behind the top crosspiece of the box (Fig.
2).
Repair
Dismantling
Stator GT 9.06L/420 K (Fig. 1): Screw out the cover mounting bolts
(8.88/8.91) and lift off the cover carefully. Detach the lead, entered
through the cover, from the plug connectors (V). Disengage the brushes
axially. Slacken the two M5 cap screws (8.89), then withdraw the stator.
Stator GTB 9.06L/420 K (Fig. 1): Slacken the M3 mounting bolt (Z), then
withdraw the plug (8.82). Turn out the cover mounting bolts (8.91) then
remove the cover. Disengage the brushes axially. Slacken the two M5 cap
screws (8.89), then withdraw the stator.
2
ENGLISH / FRANÇAIS
Rotors GT 9.06L/420 K, GTB 9.06L/420 K (Figs. 1, 2): Screw out the
M6 mounting bolt (8.85). Insert the steel pin "G" (4.8 mm x 24 mm) up to
the stop in the motor shaft (to protect the centering spigot in the shaft end).
Instead of the mounting bolt, turn in an M8 bolt (S) (minimum length 30
mm) and thus force off the rotor from the conical seat on the shaft (taper
1:10). Prevent the rotor from turning by holding the hexagon (width a cross
flats 19 mm) of the twin cone shaft.
Assembly (see Fig. 1)
The tachogenerator rotor is fitted onto the tapered shaft end A of the main
machine by means of the double taper-socketed shaft as shown in the
drawing and secured in place with a hexagonal bolt M6 (8.85) (tightening
torque 10 Nm). Maximum permissible run-out of the commutator: 0.04
mm.
The stator is positioned on the centering edge of the end shield (6.20) or
on the flange of the intermediate units (e.g. synchrogear assembly).
After fitting the stator, the brushes are inserted in the brush box radially
from the cover. The nose (N), which is bent outwards and fitted on the
brush contact stirrup (Fig. 4), must engage in the slot behind the top
crosspiece of the box (Fig. 2). The stator and rotor of the tachogenerator
are coordinated to each other and must therefore only be replaced jointly
(i.e. as a pair).
Electrical connection
GT 9.06L/420 K (Fig. 3): The electrical connection is made via the plug
connectors (V) to the connection points 2A1 (plus*) and 2A2 (minus*).
Enter the connecting lead through the screw gland (steel conduit thread
Pg7) in the cover. See that the leads lie clear under the cover in order to
prevent them dragging on the commutator.
GTB 9.06L/420 K (Fig. 3): The electrical connection is made via the plug
(8.82) outside on the casing. Slacken the M3 mounting bolt (Z), then
withdraw the plug. Remove the connecting plate together with the U-
terminals (W) from the plug (snap-in seat). Enter the connecting lead
through the screw gland and connect it to the U-terminals 2A1 (plus*) and
2A2 (minus*). When inserting the connecting plate (revolvable by 180°),
pay attention to the correct position of the plate contacts and pull back the
leads carefully.
Remarque générale
toutes les instructions de service et dans tous les autres éléments de
documentation transmis avec le produit.
Les règles de sécurité applicables aux matériels électriques jointes
(sur papier jaune) doivent être utilisées en complément de l'ensemble
de la documentation.
Toutes les prescriptions et exigences nationales, locales ou
spécifiques à l'installation doivent être respectées.
Les machines de réalisation spéciale (version, forme de construction)
peuvent différer quant aux détails techniques. En cas de doute à ce
sujet, il est instamment recommandé de contacter l'agence Siemens
compétente en indiquant la désignation de type et le numéro de
fabrication, ou de recourir aux centres de S.A.V. Siemens pour
effectuer les travaux de maintenance.
* with clockwise rotation of the drive
FRANÇAIS
Afin d'assurer la protection des personnes
et d'éviter tout dégât matériel, il est impératif
de respecter les indications contenues dans