Standard Motor Catalog

Section TR Technical Reference Guide

Thus the following comparison Table 39 applies:

Table 38: Temperature Identification Numbers Maximum Temperature Identification No. Degrees C Degrees F Acetylene 450 842 T1 300 572 T2 280 536 T2A 260 500 T2B 230 446 T2C 215 419 T2D 200 392 T3 180 356 T3A 165 329 T3B 160 320 T3C 135 275 T4 120 248 T48 100 212 T5 85 185 T6 Note: For motors having multiple UL labels, the lowest identification number will apply. CAUTION: THE RESPONSIBILITY OF SPECIFYING THE PROPER CLASS, GROUP AND DIVISION OF HAZARDOUS LOCATION RESIDES WITH THE ULTIMATE USER AND THE INVOLVED REGULATORY AGENCY. MOTORS OF HAZARDOUS (Explosive Gas) ATMOSPHERE, PER ATEX: IEC standards dealing with apparatus for use in explosive gas atmospheres are contained in a series of publication EN60079-0 through EN60079-19. The rules for classification and application of motors in these areas differ considerably from United States standards and practices. Some of the differences are noted in the following summary. Classification of Gases: IEC classifies apparatus in two broad groups as follows:

Table 39

ATEX

UL/NEC

Group II, Zone 0 Group II, Zone 1 Group II, Zone 2

Not Defined

Class I, Division 1

Class I, Division 2 Note: EC has established six temperature classes for the grouping of gases relative to the ignition temperature - T1, T2, T3, T4, T5, and T6, for the surface temperature values of this code please refer Table 38. ENVIRONMENTAL MODIFICATIONS Care is needed in using motors that have a combination of unusual environmental conditions. For example, a motor with a requirement of high altitude plus high temperature and service factor may be available only in an oversized frame. ALTITUDE The rating of standard motors assumes operation at sea level in a 40°C ambient. For purposes of standardization it is considered that there is no difference in motor operating temperature between sea level and 3300 feet altitude. The cooling effect of ventilating air is a function of its density. The atmospheric pressure and density at higher altitudes is reduced and the air cannot remove as much motor heat, causing the motor to run hotter. As a general guide, motor temperature rise increases 1% for every 330 feet above 3300 feet. To keep motor heating within safe limits at altitudes above 3300, there are the following alternatives: 1. Operated at less load (a motor with service factor rating of 1.15 or higher can be operated at altitudes up to 9000 feet with a 1.0 service factor), or 2. Operated in a lower ambient temperature per the following Table 40: Table 40 If Ambient Temperature is: Maximum Altitude with Same Service Factor is: A. Supply a motor designed for standard sea level operation which can either be: It should be remembered that, although the outdoor ambient temperature at higher altitudes is low, motors probably will be installed indoors in higher ambient temperatures. Motors applied per A1 or A2 above, will have no special altitude or temperature data on the nameplate. 30°C 20°C 6600 ft. 9900 ft.

Group 1: for application on coal mining, and Group 2: for application on other industries. Group 2 is divided into categories 1, 2 and 3. ‘Category 1 equipment’ is intended for use in Zone 0 situations. ‘Category 2 equipment’ is intended for use in Zone 1 situations. ‘Category 3 equipment’ is intended for use in Zone 2 situations.

Classifications of Hazardous Areas IEC divides the classification of hazardous areas into three zones according to the degree of hazard, defined as follows. Zone 0 - A zone in which an explosive gas-air mixture is continuously present or present for long periods. Zone 1 - A zone in which an explosive gas-air mixture is likely to occur in normal operation. Zone 2 - A zone in which an explosive gas-air mixture is not likely to occur, and if it occurs it will only exist for a short time.

TR.46

Data subject to change without notice. 10/23 • www.wolongamerica.com