Document zoBzNEpLQYxZJ0gLwkr1Bn21B

HEAVY DUTY MAGNETIC BRAKES 505 Electro-Mechanical 506 Electro-Hydraulic 3 T ECHNICAl I NFORMATION P UBIICATION 505/506 SIZE, TYPE AND DUTY CYCLE (Continued) 3. Shunt, A-c supply. A-c or D-c motor, A-c rectifier panel. a. Panel for 8" through 23" brakes. See below. The optional panel for these sizes includes the protecting circuit and a rectifier. The panel and the coil cir cuit can be continuously energized at 1007. of A-c supply voltage without overheating. Torque rating is the same as for intermittent duty. b. Panel for 30" brakes. See below. This provides D-c from an A-c supply, but without the protecting feature. Therefore brakes are rated either intermittent or con tinuous. The panel and the coil circuit, at 1007* of the A-c supply voltage, can be energized without overheating, for 1 hour for intermittent duty, or continuously for continuous duty. c. C-H and NEMA standards are that brakes will operate at 857. of the A-c supply voltage. WHEELS C-H brake wheels are made of specially formulaled ductile iron. This has friction characteristics similar to cast iron, and shock and strength characteristics like steel. Because C-H wheels are not heat treated or carburized, they retain their physical and metallurgical properties at temperatures where wheels made of other materials undergo significant changes in their microstructure. C-H wheels wear evenly and smoothly in the form of fine flakes. For this reason, wheel scoring and lining erosion are significantly reduced. LININGS C-H brake linings arc made of high grade impregnated asbestos fibers. They are technically called "folded and compressed" linings. The materials used in C-H linings result In a lining which has a constant coefficient of friction under operating conditions as well as tong life. COILS Coils are made with Class B insulation, and they are NEMA 3 enclosed in stainless steel. Coils have 2 leads (about 4" long), and each lead is supplied with a suitable lug. Colls are reversible so that the leads can point toward or away from the wheel. MOUNTING SOS and 506 brakes are designed for NEMA 1 mounting (base on horizontal surface). Optionally (hey are available for NEMA 2 mounting (base on vertical surface, magnet end up). Dimensions are the same for either mounting. CONSTRUCTION Structural members are made of ductile Iron, except the 30" base, which is a steel weldment Armatures in 8"-23" brakes are cast steel; 30" armatures are made of laminated steel. C-H brakes have only 1 true pivot pin (pull rod to arm ature). By using hardened sockets wherever possible, wear and slicking at pivot points is negligible. D-c PROTECTIVE PANEL, SHUNT ONLY in some continuous applications, the required torque is between the intermittent and the continuous rating for a brake. Normally, a larger brake would be selected. As an option, a protective panel which permits using the smaller brake is available. The scheme utilized is below. The panel uses a forcing circuit to release the brake and a timer and switch to insert-resistance into the coil circuit. This keeps the coil temperature in bounds, and Intermittent torque ratings are possible on continuously energized brakes. This same forcing and protecting scheme is used in A-c rectifier panels for 8"-23" brakes. A-C RECTIFIER PANEL, SHUNT, 8"-23" ONLY For A-c applications similar to the above, the protective panel is enlarged to include a suitable rectifier. This allows intermittent ratings for continuous applications from an A-c source. D-c voltage is 817 of A-c voltage. A-c RECTIFIER PANEL, SHUNT, 30" ONLY This optional panel does not include the forcing/protecting circuit. It only makes it possible to use 30" brakes from sn A-c source. Separate series resistance is included, as is an integral 3 phase transformer. D-c voltage is 230 V.