2 NEMA standards on power drive systems align with IEC
More U.S. standards are getting in line with international standards.
More U.S. standards are getting in line with international standards. Recently released by the National Electrical Manufacturers Association (NEMA), two ac power drive system standards adapted from International Electrotechnical Commission (IEC) standards identify specifications in the originals not applicable in the U.S., plus incorporate additional requirements necessary to conform to generally accepted wiring practices and rules for using such equipment in the U.S. The new standards are: ICS 61800-2-2005 ( Adjustable Speed Electrical Power Drive Systems, Part 2: General Requirements—Rating Specifications for Low Voltage Adjustable Frequency A.C. Power Drive Systems ) and ICS 61800-4-2004 ( Adjustable Speed Electrical Power Drive Systems: Part 4: General Requirements—Rating Specifications for A.C. Power Drive Systems Above 1000 V A.C. and not Exceeding 35 kV ).
ICS 61800-2 focuses exclusively on performance requirements for general-purpose, adjustable-speed ac drive systems, including associated power conversion, control equipment, and ac motor(s). Safety requirements are covered in other NEMA documents. Traction and electrical vehicle drives are excluded. The standard applies to systems with input voltages up to 1 kV ac (50/60 Hz) and load-side frequencies up to 600 Hz.
ICS 61800-4 covers power drive systems having line-to-line converter voltages in the 1-35 kV ac range, input-side frequency of 50 or 60 Hz, and load-side frequencies up to 600 Hz. Both standards include tutorial information and terminology to help apply power drive devices. Line harmonics and motor considerations are also addressed.
“This standard replaces material that was in other NEMA publications. It is important to align the subject matter in a uniform outline with the IEC standards, while maintaining the requirements pertinent to the use of these units in the U.S.,” says Jim Armes, chairman of NEMA’s Adjustable Speed Drives technical committee. “The national differences are the result of existing established practices.”
Pricing for ICS 61800-2 is $105; for ICS 61800-4 it’s $123. Each can be purchased online. Click here for ICS 61800-2 and click here for ICS 61800-4 , or fax your order request to Global Engineering Documents at 303-397-2740.
—Frank J. Bartos, executive editor, Control Engineering, firstname.lastname@example.org