17
Maintenance and service guide - LSN-FLSN ZONE
2 - Ex ec
5724 en - 2020.02 / c
Positioning the belts
The belts must be anti-static and flame
propagation must only occur with difficulty.
So that the belts can be correctly positioned, allow for possible
adjustment of approximately 3 % with respect to the calculated
distance E.
Force must never be used when fitting the belts.
For notched belts, position the notches in the pulley grooves.
Aligning the pulleys
Check that the motor shaft is completely parallel with that of the
receiving pulley.
Protect all rotating devices before power-up.
Adjusting the belt tension
The tension of the belts must be adjusted very carefully in
accordance with the recommendations of the belt supplier and
the calculations made when the product was specified.
Reminder:
- tension too great = unnecessary force on the bearing housings
which could lead to premature wear of the bearing unit (bearing
housing-bearings) and eventually break the shaft;
- too little tension = vibration (wearing of the bearing unit).
Fixed distance between centres:
Place a belt tensioning pulley on the slack side of the belts:
- smooth pulley on the outside of the belt;
- grooved pulley on the inside of the belts when using V-belts.
Adjustable distance between centres:
The motor is usually mounted on slide rails, which enables
optimum adjustment of the pulley alignment and the belt
tension.
Place the slide rails on a perfectly horizontal baseplate.
The lengthways position of the slide rails is determined by the
length of the belt, and the crossways position by the pulley of
the machine being driven.
Mount the slide rails firmly with the tension screws in the
direction shown in the diagram (the slide rail screw on the belt
side between the motor and the machine being driven).
Fix the slide rails to the baseplate and adjust the belt tension
as before.
Thermal protection
In-line protection
Adjusting the thermal protection (see § 6)
It must be set to the current value shown on the motor nameplate
for the voltage and frequency of the connected supply.
E
Tension screw
Tension screw
INSTALLATION AND MAINTENANCE – LSN-FLSN ZONE 2 – Ex ec
