MGM
21
GENERAL CHARACTERISTICS
BA Series
BA series consists of three phase, asynchronous brake motors totally enclosed fan cooled (TEFC). BA series range starts from 71
up to 280 frame size. The motor brakes in case of power supply failure. The braking action is always secured through a very quick
and precise stop assuring a safe and prompt stop in case of unintentional power supply failure. The brake torque remains the same
in both directions of rotation and the motor brakes without shaft axial sliding. As standard the brake is AC 3-phase voltage supply
with brake leads connected with motor leads in a single terminal board while on request it is possible to supply the brake separately
with a second terminal board or to have a DC brake supply with a built-in rectifier fitted inside the terminal box. The rectifier is
provided with over-voltage and radio frequencies emission protection devices. BA series motors tolerate high overloading rate and
are capable of withstanding overheating so as to guarantee the best reliability even under tough operating conditions. All MGM
series motors have been designed to be controlled by inverters. The motor winding insulation is class F, while class H is available
on request. Motor construction type is totally enclosed externally cooled and IP54 enclosure (IP55 and IP56 available on request).
Motors up to 132 frame size are fitted as standard with a hexagonal hole on the shaft at the non drive end to allow manual rotation,
even if power is off. All BA series motors are provided as standard with hand brake release screw.
BA series brake disc has a large lining surface that allows high brake torque, low disc wear and consequently low maintenance
cost. The brake torque can be easily adjustable to the desired value just by screwing some nuts. Thanks to its special construction
the brake friction surface is self-ventilated on the motor side, permitting a high brake workload and keeping brake time constant.
The brake lining material is asbestos free.
BA series motor frame is made of die cast, light metal on motors up to 132 size and the terminal board box, provided with cable
glands and plugs, is positioned 180
°
above the motor support feet. The frame is made of cast iron starting from 160 frame size
and the terminal box is located on the right side (drive-end view). Shields and flanges are made of aluminium on motors up to 90
frame size, and of cast iron on motors of 100 frame size and above. As standard feet are frame integrated (they are not simply
attached to the frame) on IM B3 mounting (foot mounted) making the motor very sturdy. This feature is very important for those
applications where the motor is much stressed during the starts and stops.
The brake friction surfaces are made of cast iron as a standard. The brake moving element and the brake coil have a laminated
nucleus to reduce electrical losses and to secure a very quick brake intervention.
BA series main features are its sturdy construction, quick braking action, constant braking time, high number of permissible
start/stop cycles also under severe applications, easily adjustable brake torque, low maintenance costs.