OSHA - Occupational Safety and Health Act of 1970
The "Act" was passed by the U.S. Congress an become effective in April, 1971. It is found in the Code of Federal Regulations, Title 29, Chapter XVII, Part 1910.
The purpose of the Act is to assure safe and healthful working conditions for working men and women by authorizing enforcement of standards developed under the Act; by encouraging and assisting state governments to improve and expand their own occupational safety and health programs and by providing for research, information, education and training in the field of occupational health and safety.
Nidec Motor Corporation as a company (employer) has to comply with the Act to assure health and safety to its employees. As a manufacturer of electric motors and drives, we have to make sure that the manufactured product line will also comply with OSHA. The three major requirements affection U.S. MOTORS® brand products are:
I. Subpart G-Occupational Heath and Environmental Control:
Section 1910.95 - Occupational Noise Exposure
This specification is essentially the adoption of the Walsh-Healey Act, 50-204.10, covering the same topic. It limits the noise pressure level to 90dB (A) continuous exposure for and 8-hour day. In order to comply with this requirement, users, O.E.M. s, contractors and consultants specify lower noise levels such as 85dB (A) for electric motors.
NOTES:
1. Refer to office for actual values for those ratings where Lp exceeds 90 dB (A).
2. Subtract 3 dB from all values for pressure levels (Lp) at 5 feet.
3. The sound envelope is a cylinder, with the radius 3 feet larger than the motor, extending to the top of the motor, capped with an hemisphere.
II. Subpart O-Machinery and Machine Guarding
Section 1910.219 - Mechanical Power-Transmission Apparatus
This part covers guarding of rotating and other moving parts which could cause injury because of deliberate or accidental contact with any part of a worker’s body or his clothing. Varidrives and Syncrogears are inherently guarded because of the integral, enclosed construction. The guarding of motor-to-customer’s equipment connection (such as couplings, pulleys, belts, chains, etc.) is the responsibility of the O.E.M., contractor or user.
III. Subpart S-Electrical
Section 1910.308 to 1910.331
This part is basically the adoption of the National Electrical Code NFPA 70-1997 and ANSI C1-1971 covering grounding, overload protection, hazardous locations and generally standard electrical safety procedures and rules including U/L labels for hazardous locations.
We as a manufacturer of electrical machinery has always been governed by these adopted specifications.
The 1996 NEC requires three (one per phase) rather than two over-current protectors in a 3-phase starter. These over-current protectors may be eliminated from the starter if the motor has an integral protective device (one for each phase) which will protect the motor from overloads and locked rotor condition.
THERMA-SENTRY® is this type of a device, starter heaters can, therefore, be eliminated if THERMA-SENTRY is specified, provided this is acceptable to the authorities which have jurisdiction for the installation.