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What does AAB mean?

AAB is a Stearns acronym for Armature Actuated Brakes. This best describes the Stearns Spring Set/Electrically Released (Fail Safe) DC Direct Acting Brakes, which can also be rectified for use with AC voltage. These are typically IEC Frame Brakes, with smaller sizes also available for small gear motors and NEMA Frame Sizes are also available.

What is hazardous duty?

Enclosures for standard Stearns disc brakes are designed to prevent accidental contact with the internal mechanism while keeping contaminants from the operating parts. Many installations, however, require additional protection due to the presence of explosive gases or ignitable dusts in the atmosphere. Hazardous locations are defined in the National Electrical Code (NEC) and designated by Class, Division and Group. For a better understanding of hazardous locations, or for definitions of hazardous location terminology, please refer to: http://www.ul.com/global/eng/pages/offerings/services/hazardouslocations/

Class I – Locations where the atmosphere may contain flammable gases or vapors in explosive or ignitable concentrations. An electric disc brake for Class I locations must be built in such a manner that any ignition of gases or vapors within the brake will not result in rupture of the enclosure or allow a flame or spark to travel from within the brake to the surrounding hazardous atmosphere.

Class II – Locations with combustible dust in suspension in the atmosphere. An electric disc brake for Class II locations must be enclosed in a manner which precludes entry of ignitable dusts or exit of any arcs, sparks, or hot gases which may cause ignition of dusts suspended in the surrounding atmosphere or accumulated on the enclosure. The exterior surface temperature of the brake enclosure must be limited so that it can function at its maximum-rated duty cycle without causing dehydration or carbonization of dust that accumulates on the enclosure. 

Divisions – Each hazardous-location Class is also divided into two Divisions, 1 and 2. Division 1 is a normally hazardous location. Division 2 is normally not hazardous. Division 1 brakes can be used in both types of locations. Division 2 can be used in Division 2 environments ONLY.

Groups – Class I gases and vapors are listed in four Groups A, B, C and D, based on specific properties such as maximum explosion pressure and ignition temperature. Class II airborne dusts are listed in three Groups: E, F, and G. The dust properties considered include thermal and electrical conductivity and ignition temperature.
 

What is NEMA?

NEMA stands for National Electrical Manufacturers Association. It sets the standards for motors, including brake mounting dimensions

What is a C-face?

The NEMA set of standard dimensions for mounting a brake to the motor.

NEMA defines a motor C-face as four threaded bolt holes and a machined circle located around the shaft.

What is thermal capacity?

The ability of a given brake to absorb and dissipate heat generated during brake stopping, without exceeding temperature limitations within the brake.

What is HP?

Horsepower (HP) is a unit for measuring the power of motors, or the rate of doing work. One horsepower equals 33,000 foot-pounds of work per minute, or 746 watts.

What is an IP rating?

IP or "Ingress Protection" ratings are used to define levels of sealing effectiveness of the brake enclosure against intrusion from foreign bodies (tools, dirt, etc.) and moisture. Stearns offers a range of brake enclosures/IP ratings to meet the environmental requirements of typical industrial and outdoor installations.

What is Vertical Above Mounting?

Vertical Above Mounting refers to the position in which the brake will be when mounting to a vertically mounted motor (motor shaft perpendicular to the floor), in most cases a standard end mount brake, mounted to the non-drive end of the motor will be above the motor when the drive shaft is pointing down. In the case of Double C-Face Coupler Brake, the brake will be mounted to the drive end of the brake. if the motor drive shaft is pointing up the brake mounted to the drive end will be vertical above. All Vertical Above SABs require vertical springs to support the disc pack and keep them from dragging when the motor is driving. AABs are single disc brakes and do not require any modifications for vertical mounting.

What is Vertical Below Mounting?

Vertical Below Mounting refers to the position in which the brake will be when mounting to a vertically mounted motor (motor shaft perpendicular to the floor), in most cases a standard end mount brake, mounted to the non-drive end of the motor will be below the motor when the drive shaft is pointing up. 

In the case of Double C-Face Coupler Brake, the brake will be mounted to the drive end of the brake. If the motor drive shaft is pointing down the brake mounted to the drive end will be vertical below. Most Vertical Below SABs require vertical springs to support the disc pack and keep them from dragging when the motor is driving. AABs are single disc brakes and do not require any modifications for vertical mounting.