Pulleys And V-Belts; Inspection Of Pulleys; Replacement Of V-Belts; V-Belt Tension - Grundfos BMEX Serie Instrucciones De Instalación Y Funcionamiento

12. Pulleys and V-belts

12.1 Inspection of pulleys

Inspect the pulley grooves for wear. See fig. 17. Belt life will be
reduced if the grooves are worn.
Wear
New V-belt and pulley groove
Worn V-belt and pulley groove
Fig. 17 Examples of new and worn pulley grooves
Use, for instance, pulley gauges to determine whether the
grooves are worn. See fig. 18.
The motor pulley groove is 38 ° and the pump pulley groove is
34 °.
Pulley gauge
Fig. 18 Use of pulley gauges
A torch may be useful when inspecting the grooves. Do not be
misled by shiny grooves. Grooves that are shiny are often
polished because of heavy wear. Inspect the pulley grooves for
corrosion or pitting. If corroded or pitted surfaces are found, the
pulley should be replaced.
Worn pulleys must be replaced to ensure trouble-free
Note
operation.
Checking and correcting pulley alignment
Misaligned pulleys will accelerate wear of belts and pulley
grooves.
Check the alignment by placing a steel straightedge across the
pulley faces so that it touches all four contact points. See fig. 19.
Correct the alignment, if required.
Fig. 19 Correct alignment
14

13. Replacement of V-belts

Procedure:
Caution
All V-belts must be replaced by new belts.
1. Remove oil and impurities from the pulley grooves.
2. Place the V-belts loosely in the pulley grooves without using
force or tools of any kind.
3. Adjust the V-belt tension to the value stated in section
belt tension.

14. V-belt tension

Correct belt tension is decisive for long and trouble-free
operation.
This section refers to section 16. Recommended V-belt
1. Move the motor towards or away from the pump until the
correct tension has been obtained, i.e. between T
2. Rotate the motor and pump shafts a few times by means of
the V-belt before checking the T
3. Adjust the V-belt tension to the value stated.
4. Check the V-belt tension after 1 to 4 hours of operation at full
load.
5. Adjust the V-belt tension to the value stated.
6. The belt tension should be checked regularly according to the
recommended values.
The belt tension can be measured through a hole in the protective
guard.
V-belts and pulleys must be checked every 6 months.
We recommend that you replace the V-belts once a year.
14. V-
tension.
-T .
min. max.
-T value.
min. max.