3RV Motor Starter Protectors/Circuit Breakers up to 100 A General data Characteristic curves The time/current characteristic, the current limiting characteris- tics and the I 2 t characteristic curves were determined according to EN/IEC 60947. Time/current characteristic curves, current limiting characteristic curves and I 2 t curves can be ordered from "Technical Assistance": Either by e-mail to: technical-assistance@siemens.com Or on the Internet:
http:/www.siemens.com/automation/service&support The tripping characteristic of the inverse-time delayed overload release (thermal overload releases, 'a' releases) for DC and AC with a frequency of 0 Hz to 400 Hz applies for the time/current characteristic. The characteristic curves apply to the cold state; at operating temperature, the tripping times of the thermal releases are redu- ced to approximately 25 %. 3RV16 voltage transformer circuit breakers up to 3 A Under normal operating conditions, all three poles of the device must be loaded. The three main current paths must be con- nected in series in order to protect single-phase or DC loads.
The specified tripping characteristics of the thermal overload re- lease (a) correspond to the mean value of the scatter band in the cold state. At operating temperature, these times are reduced to approximately 25 % of the specified values. With two-pole and three-pole loading, the maximum deviation in the tripping time of 3 times the setting current and upwards is ± 20 % and thus in accordance with EN 60079. The characteristic curves below are schematic representations. Precise characteristic curves can be ordered from "Technical Assistance": Either by e-mail to: technical-assistance@siemens.com Or on the Internet:
http:/www.siemens.com/automation/service&support The tripping characteristics for the instantaneous, electromag- netic electronic trip units (short-circuit releases, 'n' releases) are based on the rated current I n that also represents the maximum value of the setting range for motor starter protectors with adjus- table overload releases. If the current is set to a lower value, the tripping current of the 'n' release is increased by a correspon- ding factor. The characteristic curves of the electromagnetic electronic trip units apply to frequencies of 50 Hz/60 Hz.
Appropriate correc- tion factors must be used for lower frequencies down to 16 2 / 3 Hz, for higher frequencies up to 400 Hz and for DC. NSB0_01352b 1000 s Opening time 10 000 100 100 min 60 40 5000 10 10 2000 1000 1 5 500 200 0,1 1 2 100 0,01 50 20 1 2 4 6 10 20 40 A100 60 10 5 1 2 3 3 A / 20 A 2.5 A / 10.5 A 1.4 A / 6 A 2 a) Thermal overload release b) Instantaneous electromagnetic trip unit 0,5 1 0,2 0,05 0,1 0,02 0,01 0,005 0,6 0,8 1 2 3 4 6 8 10 0,001 20 30 40 80 x n 0,002 60 Current Schematic representation of typical time/current characteristic of 3RV10 The above characteristic curve for the motor starter protector re- lates to a specific setting range.
It is, however, also valid as a schematic representation of motor starter protectors with other current ranges. 23 Siemens · 2009 a) 1 2 3 b) NSB0_00004b 3-pole loading Class 20 3-pole loading Class 10 2-pole loading Class 10