Electric Drives

Electric drives overlap both of these technologies at their upper limits of speed and

 

extend to elevator speeds of more than 700 feet per minute.

 

Cable traction elevators are suspended by cable which is wrapped around a drum. The

 

elevator has a counter weight to eliminate having to dead lift the load as in a hoisting

 

application. These cable drums traditionally have been driven by DC motors powered

 

from a motor - generator set. With the introduction of SCR controls in the 60's, many of

 

these were built with SCR controls. The DC motor offers high starting torques and good

 

speed control. The SCR control is relatively simple and reliable in design.

 

Cable traction elevators can be further sub-divided based on how the torque is

 

transmitted from the motor to the cable drum. These sub-groups are:

 

1.

Worm gear driven at a speed of 50 to 450 FPM.

 

2.

Helical gear driven at a speed of 200 to 500 FPM.

 

3.

Gearless which operates at 400 to 700 FPM and above.

The most common types of elevators that use Baldor drives are cable traction elevators. The DC SCR control is used with many worm gear and gear-less elevators operating in the 350 FPM range. The Series 20H Digital DC SCR control is a good selection for use on gear-less and gear driven elevators. Typical motor requirements are 15 to 75 horsepower.

Inverters may be used on worm gear cable traction elevators operating at 100 to 150

FPM. These slower elevators typically require 7.5 to 10 horsepower motors.

AC powered elevators that operate above 150 FPM should use a Baldor Vector Drive. Vector drives perform well in the 150 to above 700 FPM range. Typical horsepower requirements are 15 to 50 HP.

There are several factors that contribute to a good elevator drive. The predominant requirement for a good elevator is smooth operation without any jerky movement. Another requirement is accurate floor leveling capability. Baldor's ability to offer better value is the reason many customers select Baldor products for their elevator applications.

3-2 Application Considerations

MN770

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Baldor MN770 manual Electric Drives
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MN770 specifications

The Baldor MN770 is an impressive industrial motor designed for a variety of applications, showcasing robust construction and advanced technology. Known for its reliability and efficiency, the MN770 is manufactured by Baldor Electric Company, a prominent name in the electric motor industry.

One of the main features of the MN770 is its high-efficiency design. This motor adheres to stringent efficiency standards, helping to reduce energy consumption and lower operational costs. It typically meets or exceeds NEMA Premium Efficiency ratings, making it an excellent choice for businesses looking to optimize their energy use.

The MN770 motor is built with a durable cast iron frame, ensuring longevity and resistance to harsh operating conditions. Its weatherproof design is ideal for both indoor and outdoor applications, making it suitable for various environments, including manufacturing plants, water treatment facilities, and agricultural operations.

Another significant characteristic of the MN770 is its versatility. The motor is available in a range of horsepower ratings, allowing users to select the model that best fits their specific needs. Additionally, it offers various mounting configurations and voltage options, further enhancing its adaptability for diverse applications.

The motor utilizes advanced insulation systems and cooling technologies to ensure optimal performance and a longer lifespan. The robust design helps to dissipate heat effectively, enabling the motor to operate efficiently even under heavy loads. This characteristic is essential for applications requiring continuous operation without compromising reliability.

Moreover, the Baldor MN770 incorporates advanced design features such as precision-balanced rotors and high-performance bearings. These characteristics contribute to reduced vibration and noise levels, promoting a quieter working environment and improving overall operation efficiency.

In summary, the Baldor MN770 motor stands out due to its high efficiency, robust construction, versatility, and advanced technologies. Its ability to perform reliably in various industrial applications makes it a popular choice among engineers and facility managers. Investing in the MN770 not only enhances operational efficiency but also supports sustainability efforts by reducing energy consumption in industrial environments.
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