© Siemens AG 2009 General information General criteria for the selection of devices A maximum installation height of 2000 m applies for all elec- tromechanical controlgear, and 1000 m for soft starters and solid-state contactors. Greater installation heights are possi- ble with derating. For details refer to Catalog LV1 T. The motor starter protectors, contactors, solid-state switching devices, soft starters and overload relays in the following ta- bles are all specified in their basic versions, i.e. (in particular) without accessories. It goes without saying that accessories, such as auxiliary switches, auxiliary trip units etc. can be used at any time.
Trip classes CLASS 5, CLASS 10, CLASS 20, CLASS 30 and CLASS 40 The contactors listed have a rated control supply voltage U s of 230 V AC, 50 Hz. Versions with other voltages can also be used. Trip classes, according to IEC 60947-4-1, define the time inter- vals within which the protection equipment (overload release of a motor starter protector or overload relay) must trip from the cold state, for a symmetrical, three-phase load with a 7.2- fold set current I e . The 3RU11 thermal overload relay and the 3RB20/3RB21 solid- state overload relays can generally be directly mounted onto the contactor. Exceptions are specified in the footnotes of the respective tables.
The 3RB22/3RB23 solid-state overload relay and the SIMOCODE pro 3UF7 motor protection and control de- vice are essentially used for stand-alone installation. In their basic version, these devices are specified with a rated control supply voltage of 230 V AC as well. No sizes are specified for the "Molded-Case Circuit Breakers" (MCCB) as for SIRIUS. The tripping times are as follows: ■ CLASS 5 and CLASS 10 between 2 s and 10 s, ■ CLASS 20 between 4 s and 20 s, ■ CLASS 30 between 9 s and 30 s, ■ CLASS 40 between 30 s and 40 s. Mounting the combinations 120 100 When mounting the devices, specific arcing spaces must be maintained so that short-circuits can be cleared safely and re- liably.
The appropriate installation guidelines are listed sepa- rately for 400/440/480/500/550 V AC and 690 V AC on page 70 ff. min 50 20 10 5 Tripping time 2 1 50 The technical data of the individual devices must be taken into account when selecting a device. 20 s 10 5 400/440/480/500/550/690 V AC 2 The subsequent tables are structured according to mains volt- ages of 400/440/480/500/550/690 V AC for grounded net- works (at 50 and 60 Hz) generally found in IEC regions. With a few exceptions, tests are carried out with a test voltage which lies 10 % above these values (further details can be found in the test reports).
Thus, the specified combinations can also be used for other networks as long as their maximum voltage does not exceed the test voltage. This means, for instance, the combinations for 400 V can also be used for 415 V networks that have a line supply tolerance of +5 %. 0,6 Tripping current (mean values) 1 2 5 10x e In practice, devices with trip CLASS 5 and CLASS 10 are gener- ally used. These devices are designed for standard applica- tions. CLASS 5 and CLASS 10 are often referred to as normal starting devices. Combinations for CLASS 20, CLASS 30 and CLASS 40 are avail- able for applications where a higher starting current is re- quired for a prolonged period.
In this case, using standard de- vices of CLASS 5 and CLASS 10 would result in unwanted trip- ping. CLASS 20, CLASS 30 and CLASS 40 are also known as heavy starting devices. Large fan motors are an example of this type of application. Ambient conditions A maximum ambient temperature of 60 °C applies for all elec- tromechanical controlgear, and 40 °C for soft starters and sol- id-state contactors. Higher temperatures are possible with derating. For details refer to Catalog LV1 T or contact Technical Assistance. Introduction 6 NSB0_00298a CLASS 30 25 20