Two new NEMA standards approved
The National Electrical Manufacturers Association (NEMA) has released two standards that are adaptations from IEC standards:
ICS 61800-2-2005, Adjustable Speed Electrical Power Drive Systems: Part 2: General Requirements-Rating Specifications for Low Voltage, Adjustable Frequency, ac Power Drive Systems,
ICS 61800-4-2004, Adjustable Speed Electrical Power Drive Systems: Part 4: General Requirements-Rating Specifications for ac Power Drive Systems Above 1000 V ac and not Exceeding 35 kV.
Both documents contain amendments to identify those specifications in the original IEC standard that are not applicable in the United States. They also incorporates those additional requirements necessary to conform to the generally accepted wiring practices and rules for use of such equipment in the United States.
“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.”