INSULATION CLASS TEMPERATURE RISE CLASS - Nidec Leroy …

1 TECHNICAL NOTE. TN11. INSULATION CLASS /. TEMPERATURE RISE CLASS . PREAMBLE. This technical note aims at: Clarifying INSULATION CLASS and TEMPERATURE Rise CLASS notions Comparing possible systems available ( INSULATION CLASS H / TEMPERATURE rise F vs. INSULATION CLASS F /. TEMPERATURE rise B). Showing evidences on generator lifetime extension, by sizing the generator on a lower TEMPERATURE Rise CLASS INSULATION CLASS . The IEC 60085 specifies that an INSULATION system permanently submitted to its INSULATION CLASS TEMPERATURE has a life expectancy of 20. 000h. It defines the INSULATION CLASS temperatures as follows: INSULATION CLASS H F B. TEMPERATURE 180 C 155 C 130 C.

2 (Reference Document: IEC 60085). All Leroy -SOMERTM generators windings are manufactured with CLASS H INSULATION system. TEMPERATURE RISE CLASS . The TEMPERATURE rise CLASS is the maximum allowed difference between the measured TEMPERATURE , after TEMPERATURE stabilisation, of one of the active generator components (stator or rotor copper) and the cooling fluid TEMPERATURE ( ambient air TEMPERATURE for instance, at 40 C). In other words, this is the maximum allowed TEMPERATURE increase, from cold to warm condition, when the alternator is running at rated values. The IEC 60034-1 defines the TEMPERATURE rise CLASS as follows: TEMPERATURE rise CLASS H F B.

3 TEMPERATURE limits 125 K 105 K 80 K. (Reference Document: IEC 60034-1 - Table 7, Resistance method of measurement). Note: TEMPERATURE rise data are stated in Kelvin (K). INSULATION CLASS AND TEMPERATURE RISE CLASS . T . We define the following: INSULATION CLASS T . Thermal Margin = INSULATION CLASS TEMPERATURE Thermal Margin Operating TEMPERATURE Where : Operating TEMPERATURE = TEMPERATURE Rise CLASS TEMPERATURE Rise + Ambient TEMPERATURE CLASS (K). Operating TEMPERATURE Note : When a generator system is designated as H / F . The 1st letter defines the INSULATION CLASS Ambient The 2nd letter defines the TEMPERATURE Rise CLASS TEMPERATURE ( C). H / F VERSUS F / B.

4 Thermal margin = INSULATION CLASS TEMPERATURE Total Temp erature Thermal margin = INSULATION CLASS TEMPERATURE - Total TEMPERATURE 200. TEMPERATURE defined by H. 180. Thermal INSULATION CLASS : 180 C. TEMPERATURE defined by F. 155 Margin: 35 K. Thermal INSULATION CLASS : 155 C. Margin: 35 K. Op. TEMPERATURE : 145 C. 120. TEMPERATURE ( C). Op. TEMPERATURE : 120 C. CLASS F CLASS B. Temp . Rise: Temp . Rise: 105 K 80 K. 40. Ambient Ambient TEMPERATURE TEMPERATURE 0. INSULATION CLASS H INSULATION CLASS F. and and TEMPERATURE Rise CLASS F TEMPERATURE Rise CLASS B. In other words: Leroy -SOMERTM Usual requirement INSULATION CLASS H / TEMPERATURE Rise CLASS F INSULATION CLASS F / TEMPERATURE Rise CLASS B.

5 Thermal margin: 180-(105+40) = 35 K Thermal margin: 155-(80 +40) = 35 K. ---------------------------------------- ---------------------------------------- ---------------------------------------- ------- Generators designed as F / B or H / F have the same thermal margin, and hence the same INSULATION system lifetime. Using H / F designs enables the selection of more compact and economic generators with the same design life time. ---------------------------------------- ---------------------------------------- ---------------------------------------- ------- 2/3 TECHNICAL NOTE TN11 - GENERATOR INSULATION LIFETIME EXTENSION POSSIBILITIES. The Rule of 10 ( Arrhenius Equation) can be adapted to approximate the relationship between INSULATION lifetime and operating TEMPERATURE .

6 This rule states that if a generator's operating TEMPERATURE is reduced by 10 C, the INSULATION system lifetime is doubled. Using a higher INSULATION CLASS , associated with a lower TEMPERATURE Rise CLASS , allows a drastic increase the INSULATION lifetime. INSULATION CLASS H & F vs. Operating TEMPERATURE (OT in C). INSULATION CLASS H & F vs. Operating TEMPERATURE (OT in C). 10 000 000. 1 280 000. Continuous operating time (Hours). IEC 60085 design value for 226 274 an INSULATION CLASS F. 100 000. IEC 60085 design value for 56 569. 40 000 an INSULATION CLASS H. 20 000. 10 000. INSULATION CLASS F INSULATION CLASS H. 100. Op. T. CLASS B Op. T. CLASS F Op.

7 T. CLASS H. 100 155 165 180 200 220. 120 C 145 C 165 C. TEMPERATURE ( C). Operating TEMPERATURE of the considered TEMPERATURE Rise CLASS (IC01 Cooling, 40 C Ambient TEMPERATURE ). H & F INSULATION lifetimes, depending on the selected TEMPERATURE Rise CLASS : INSULATION CLASS H INSULATION CLASS F. System Lifetime (Years) System Lifetime (Years). Operated at CLASS H TEMPERATURE rise H/H N/A N/A. Operated at CLASS F TEMPERATURE rise H/F 26 F/F Operated at CLASS B TEMPERATURE rise H/B 146 F/B 26. ---------------------------------------- ---------------------------------------- ---------------------------------------- ------- H / B designed generators have oversized INSULATION lifetime.

8 At least 5 times the expected lifetime of F/B design for the same active part size and mass. This design can be offered by Nidec Power. ---------------------------------------- ---------------------------------------- ---------------------------------------- ------- 3/3.