Checking the belt drive
Belt-driven fans are supplied with the belt run in and pretensioned. If the fan is equipped with a belt tensioner,
maintenance of the belt drive is restricted to a check of belt wear every 5,000 to 10,000 service hours depending on
application. Belt drives without belt tensioner require belt tension to be checked every 5,000 to 8,000 service hours,
again depending on application.
Necessary setting values F
p
(checking force) and t
e
will be found in the Fan Identity Card. The belt is retensioned, if
necessary, by setting of the motor sliding plate. It is checked by means of a predetermined checking force F
p
which is
applied to the middle of the load strand and has to deflect the belt from the straight by the amount t
e
. Never forget to
rearrange the belt guard before starting after maintenance.
The fan has to be inspected thoroughly after about ten years. An expert has then to decide on its further use.
5. Repair instructions
Any operation on the fan is impermissible unless it has been switched off. Make sure that it cannot be switched on
during repair work.
After repair proceed as in initial starting (Section 3.3).
5.1 Cleaning
For cleaning the fan inside use the cleaning opening (in special accessories) or open the complete housing.
Cleaning liquids must not damage the plastic components by partial dissolving.
Never use hard objects for mechanical cleaning.
5.2 VRE-W direct-driven fans
For motor exchange demount the fan into its main assemblies.
Demounting
Disconnect fan from power supply and take it out of the plant.
Open suction socket (mark mounting position).
Demount upper half of divided housing.
Remove hub protecting cap (caps glued or welded on must be destroyed).
Loosen hub securing fixture and pull off runner.
Demount housing from base (not necessary in cases of divided housing).
Demount motor and repair as specified in motor operating instructions or renew motor.
Mounting
Mounting is in reverse order. The following items must be considered:
Use motor types only if the manufacturers have agreed.
Reattach screw covers.
Renew securing elements of hub connection.
Renew hub protecting caps glued or welded on.
Take care of mounting position of suction socket.
5
OI-VRE 05/02
