What You Should Know About IEC and Electric Motors

Transcription

1 Q&A What You Should Know About IEC and Electric Motors

2 IEC Q&A IEC standards are recognized around the world as a benchmark for products such as industrial electric motors. These standards help ensure that customers will receive consistent product performance and mounting dimensions no matter where products are applied around the world.

3 What is IEC? IEC is an abbreviation for the International Electrotechnical Commission. It was founded in 1906 as the result of a resolution passed at the International Electrical Congress held in St. Louis, Missouri USA in The purpose of this organization is to help consumers around the world by setting consistent standards for product performance, dimensions, etc. How Does IEC Apply to Industrial Motors? IEC 34 is an Electrical Standard which defines cooling methods and protection factors for the design of Rotating Electrical Machinery. It is comprised of 19 sections which define specific design factors. For example, IEC 34-1 defines rating and performance standards and IEC 34-9 specifies noise standards. In addition to Electrical Standards, IEC 72 defines Mechanical Design Properties such as dimensions for rotating electrical machines. What Types of Motors are Covered? Throughout IEC 34 and IEC 72 are standards for AC motors, DC motors and synchronous motors with shaft heights from 56 mm to 400 mm. 1

4 Does IEC 34 Have Standards for Voltage Variation? Yes. IEC 34-1 paragraph 13 specifies that motors shall be capable of providing their rated output when rated frequency is applied by a voltage that may vary from 95 to 105 percent of their rated voltage. How Are Service Factors Applied? The term Service Factor is not defined by IEC. Temperature rise, ambient and altitude capability are defined by the KW rating shown on the nameplate. As a result, to add a Service Factor to an IEC motor, the next higher KW rating would be chosen. Are IEC Maximum Allowable Temperature Rises by Class of Insulation the Same as NEMA Standards? No. IEC specifies five classics of insulation with corresponding temperature rises by resistance: Class A = 60 C Class E = 75 C Class F = 100 C Class H = 125 C Class B = 80 C 2

5 Which Temperature Rise Class Will Reliance Electric IEC Motors Meet? Class F insulation system with an IEC Class B temperature rise (80 C). Must IEC Motors have Metric Hardware? Metric fasteners must be included at points of user interface such as the conduit box. However, IEC does not require metric fasteners in locations normally not serviced by a user such as end bracket bolts. Do IEC Standards Require the Use of Terminal Blocks in the Conduit Box? No, this is an European standard and not required by IEC. However, inspectors often consider a motor incomplete without a terminal block. As a result, all standard Reliance Electric IEC motors will include them unless a required modification prohibits their use. 3

6 When Thermal Protection is Required for a Motor Being Shipped to Europe, Which is Right a Thermostat or Thermistor? A Thermistor is the thermal protection device most often used in Europe. However, customers should always be asked which one they prefer. How Are IEC Motor Enclosures Defined? IEC standards have two categories for enclosures: Protection and Cooling Methods. For example, a NEMA standard TEFC motor is defined by IEC as IP53/IC 41. A NEMA standard TEAO equals IEC IP53/IC48 and a NEMA TENV is the same as IEC IP53/IC40. IP and IC codes must be included in the Enclosure block on Order Entry Forms for IEC motors. If TEFC and IP53/IC41 Enclosures Are the Same, Why is the IP54/IC41 Enclosure the Standard for Reliance Electric IEC Motors? Internationally, the IP53 code is not normally ordered. IP54 enclosures are more widely used in specifications and exceed IP53 capabilities (such as increased protection from moisture). In addition to the standard IP54 protection code, IP55 and IP56 are available to provide greater degrees of protection. 4

7 How Are Mounting Positions Defined? IEC standards define mounting positions and flanges with a series of codes; B3 for foot mounted no flange, B5 for footless with either a FF or FT flange, etc. For a complete list of IEC mounting positions, refer to Reliance Instruction Manual B All orders must specify the proper mounting position (i.e., B5) and flange (i.e., FF) code. B3 The NEMA Standard Mounting Position is F-1. What is the Comparable IEC Standard? While IEC B3/L is the equivalent to NEMA F-1, the IEC standard mounting position is B3. It is foot mounted without a flange and has the conduit box mounted on the right side when facing the shaft end of the motor. The corresponding NEMA designation for this arrangement is F-2. NEMA F-1 / IEC B3/L NEMA F-2 / IEC B3 What is the Standard Direction of Shaft Rotation for IEC Motors? Clockwise (CW) shaft rotation when facing the shaft end of the motor is the standard for IEC motors. All Reliance Electric IEC motors are shipped with bi-directional shaft rotation unless otherwise specified. 5

8 What Are The Types of Flanges Specified by IEC? IEC standards define FF, FT and FI flanges. FF and FT flanges are available for frame sizes from 56 to 280. The FF flange has through bolt holes where the FT flange has threaded bolt holes. FI flanges are limited to 160 frame sizes and smaller. IEC FF and FT flanges are similar to NEMA D-flanges Are Reliance Electric IEC Motors Defined as Energy Efficient? Yes. Even though IEC standards do not define motor efficiency, these motors meet or exceed the requirements of the USA Energy Policy Act. 6

9 What is the IEC Standard for P-base Motors? There are no specific IEC axial thrust standards for motor mounting with the shaft facing down. The only applicable IEC standards are FF for flange and VI for shaft down mounting. Axial thrust capacity and shaft requirements must be defined by the customer. In instances where thrust capacity is a factor, contact a Reliance Electric Motor Application Specialist. Do Reliance Electric IEC Motors Meet CE? Every Reliance IEC motor manufactured in a North American facility will include the CE mark and include a Declaration of Conformity for 112 through 280 frame sizes. Will Reliance IEC Motors Carry a CSA Logo? Yes. A CSA logo as pictured here should appear on the nameplate. What are Reliance Electric M-2000 Motors? Reliance Electric IEC motors are designed and manufactured to meet IEC electrical and mechanical standards. M-2000 AC motors are available for customers who need a motor with IEC dimensions while meeting NEMA electrical standards. These motors are commonly used by companies which ship machinery with motors into the United States and Canada. They are also used to replace motors on equipment which was manufactured outside of North America. 7

10 How Can I Find Out More About IEC Motors? More information is included in Reliance Electric IEC motor brochures, data sheets and instruction manuals. For specific questions, contact your Rockwell Automation sales engineer. 8

11 Comparison of IEC Metric vs. Nema Mounting Dimensions D H 2F BA 2E FRAME SIZE D 2E 2F BA H IEC NEMA IEC NEMA IEC NEMA IEC NEMA IEC NEMA IEC NEMA 90S L S M S M M L M L M L S M S M S M S M S M S M Note: All dimensions in mm.

12 Rockwell Automation / Reliance Electric / Euclid Avenue / Cleveland, OH USA /(1) / Printed in U.S. B M