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Idiomas disponibles
Idiomas disponibles
Maintenance
Maintenance operations must be carried out by qualified personnel, and only after having disconnected the plant or the
motor from the electrical supply (including any possible auxiliaries and especially anti-condensation heaters) and after
having checked that no load is applied to the driveshaft.
Discharge all capacitors before servicing a single phase motor
Prevent uncontrolled restarting of the motor as this may be extremely hazardous for the operator and may cause serious
damage.
For security reasons the hexagonal 'T' key never must be fitted on the motor but removed and kept by the plant maintenance
responsible after every intervention.
The hexagonal 'T' key must be used only after having disconnected the motor from the electrical supply and after having
checked that no load is applied to the driveshaft.
The operations which must be carried out periodically in order to ensure the correct functioning of the MGM brake motor are
listed further on. The frequency of inspection depends on the particular motor duty (number of start/stop, applied moment of
inertia, environment conditions and so on). Generally it's advisable to proceed to the first inspection after few weeks of
working and to draw up a periodical maintenance plan. Anyway it's recommended to provide inspections at least twice a
year. For specific information pls contact the M.G.M. motori elettrici S.p.A. organization.
- Periodically check that the motor properly operates without abnormal noise or vibrations which could mean deterioration of bearings.
Bearings mounted on MGM motors are of life-lubricated double-screen waterproof type.
- Check that motor is tightly fixed through flange and feet.
- Check that current doesn't exceed the value written on the nameplate.
- Check that air openings for ventilation are not obstructed.
- Check that feeding cables and earth grounding are correctly tightened.
- As a result of normal wear of the brake disc lining, check that the air gap does not exceed the values shown on table 1. Please
note that the brake linings wear is greater during the run-in. (few thousands stops). For the air gap adjustment, follow the
instructions given into the paragraph "Air Gap Adjustment".
-Check the wear on both friction surfaces of the brake disc to be sure that their thickness is not less than 1,5mm (BM 56÷80);
2,0mm (BM 90÷132); 3mm (Bm160). Verify also that there are no damages on disc surfaces and in the hub. (For replacement,
refer to the paragraph "Brake Disc Replacement").
- Verify periodically that the braking torque is suitable. If needed, proceed to its adjustment as stated in the paragraph "Braking torque
adjustment".
- All brake assembly components are subject to wear. In consideration of safety it's needed to replace them periodically as
preventive action. The replacement frequency comes from the motor duty (number of start/stop, applied moment of inertia,
environment conditions and so on), we recommend however to replace them at least every 18 months.
Braking Torque Adjustment
The braking torque can be adjusted up to the maximum rate as shown on nameplate. To adjust the braking torque it is possible to
operate on the screw of the adjustable springs if there are some or vary the number or type of fixed springs (78) inserted into the brake
(75). To adjust the braking torque by varying number of fixed springs it has to be operated according to instructions given on par. "Brake
coil replacement". Then, loosing the connecting screws (77) and after taking out the brake moving element (74) draw the fixed springs
out in order to reduce the braking torque. The compression by the springs on the moving element must be as even as possible. After
adjusting check that the brake correctly releases.
Brake Disc Replacement
Loosen the end cover screws (82) of the end cover (76) and remove it. After removing the fan snap ring(72), sliding the fan (71),
removing the elastic washer and the hand release - if they are present - loosen the connecting screws (77), unscrew the fixing screws
(79) and draw out the brake coil - brake moving element group (74-75). Take off the old brake disk (73) and insert the new one. For re-
assembling, proceed backwards and remember to adjust the air gap. It is advisable to handle the new brake disk with clean hands, as
even a small trace of grease will decrease the braking performance and increase the noise.
Brake Coil Replacement
Disconnect the two terminals of the brake coil inside the terminal box. Unscrew the end cover screws (82) of the end cover (76) and
remove it. After removing the fan snap spring (72), sliding the fan (71), removing the elastic washer and the hand release if they are
present, loosen the fixing screws (79) and take out the brake coil (75). Insert the new brake coil, proceeding backwards with the
operations described. Remember to adjust the air gap.
Air Gap Adjustment
The air gap between the brake moving element (74) and the brake coil (75), which can be surveyed by means of a thickness gauge,
must be as shown on table 1. In order to set the air gap back to the required value, operate on the connecting screws (77), by turning the
fixing screws (79) to obtain the brake coil's (75) forwards the rear cover (84). With a constant air gap at the fixing screws operate on
connecting screws again clockwise so to block the brake coil in the new position. Once the operation is completed, check the air gap
again and, if necessary, repeat the operation.
On BMBM motors the airgap must be adjusted on both brake assemblies.
On BM56 motors and BML motors it'isn't possibile to adjust the airgap. When the airgap exceeds the maximum value indicated on table
1 it's necessary to replace the brake disc.
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