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| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BM series brake group | | | | | | | | | | General description | | | | | | | | | | BM series motors are equipped with DC brake coil. DC brake coil is supplied through a rectifier located in the terminal box (standard voltage supply is 230V 50/60 Hz). The rectifier is provided with over-voltage and radio frequencies emission protection devices. The brake torque remains the same in both directions of rotation and the motor brakes without shaft axial sliding. Brake torque can be set loosening or tightening the adjustable industrial springslTsfl where available or removing the central springs or replacing the fixed ones. Never set the brake torque to a higher value than the one indicated on the motor nameplate. BM series motors are fitted as a standard with a hexagonal hole on the shaft at non drive end to allow manual rotation. On request BM series motors can be provided with brake release return lever located on the motor side. | | | | | | | | | | Air gap adjustment | | | | | | | | | | The air gap pcf that is the distance between the two magnetic cores, the brake coil [/J and brake moving element [/J, must stay within the value expressed in the chart below. It is advisable to check periodically the air gap because it increases as a consequence of the brake disc wear. In order to restore the air gap within the proper value release the connecting screws [I, move the brake coil [§| towards the brake moving element t/loperating on the fixing screws [/<!. Once this operation has been settled be sure to tighten clockwise the connecting screws [/J so to fasten again the brake coil. | | | | | | i | | | | | | | | | | | | | | | | | | | | | | | | | | | Frame Size | 63/71 | 80 | 90 | 100 | 112 | 132 | 160 | | | | Min Air Gap[mm] | 0,2 | 0,2 | 0,3 | 0,3 | 0,3 | 0,4 | 0,4 | | | | Max Air Gap[mm] | 0,6 | 0,7 | 0,8 | 0,9 | 1,0 | 1,1 | 1,1 | | | | | | | | | | | | | | | | | | | | | | | Permissible start frequency with load | | | | | | | | | | The technical data tables provide the ideal no-load start frequency (Zo). The permissible start frequency when an external load is applied (Z load) can be calculated as follows: Zload=Zo.K • R K 1,2 | | | | | | | | | | 1 0,8 0,6 0,4 0,2 | | | | | | 0,8 0,6 0,4 0,2 | | | | | | | | | | | | | | 0 | | 0 | | | | | | r 0,8 | | | | | | | | | | | 0 | | 0,6 | | | 1,0 | | | | | | 0 | | 8 | | | | | | b | | | | | | | | | | | | | | | | | | Tr / Ts | | | | | | VJmot | | | | | | | | | | | | | | where "Zo" is the table-value for the selected motor and "K" and "R" are factors determined by the curves on the side; the factor "K" refers to the calculated ratio between the moment of inertia of the applied load (Japp) and that of the motor (Jmot) while the factor "R" is the calculated ratio between the resisting torque (Tr) and the starting torque (Ts). This calculation gives an approximative indication only. If the required starting frequency is close to Zload, it is advisable to use a motor equipped with thermal protectors. It is necessary to check the maximum energy dissipation limit of the brake group and the maximum motor RPM on those application where high moment of inertia is involved. Please contact MGM technical staff for additional information. | | | | | | | | | | 38 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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