Datasheet

3RV Molded Case Motor Starter Protectors up to 800 A
General data
46
Siemens · 2010
■ Characteristic curves
Example characteristic of a 3RV10 molded case motor starter protector with electronic trip unit for motor protection (TU 4)
TU = trip unit
Protection from overload (L trip unit)
The L protection function protects the motor from overload and
is temperature-compensated according to IEC 60947-4-1 and
sensitive to phase failure and phase unbalance. With the DIP
switches on the trip unit the function can be set by hand to
between 0.4 and 1 times the rated current. The trip class can
also be set here.
A pre-alarm LED and an alarm LED indicate violation of the pre-
alarm threshold (0.9 times the tripping current) and the alarm
threshold (1.05 times the tripping current).
Protection from short-circuits (I trip unit)
This function protects the motor from short-circuits between two
phases. It always responds when a phase exceeds the set trip-
ping value (6 to 12 times the rated current). Safe start-up is gu-
aranteed.
Protection in the event of rotor blockage (R trip unit), can be
switched off
With this function the motor is protected in the event of rotor blo-
ckage during operation. During motor start-up, this function is
blocked for the time defined by the trip class. Thereafter the trip
unit trips after 1 to 10 s at 3 to 10 times the tripping current for
the overload (each can be set by means of DIP switches).
Protection in the event of phase failure or phase unbalance
(U trip unit), can be switched off
This function protects the motor when it is important to check in
particular for phase failure and phase unbalance. The function
responds when the rms value of the current in one or two phases
remains 4 seconds long below the limit threshold of 0.4 times the
tripping current for the overload.
Time/current characteristic curves, current limiting characteristic
curves and I
2
t curves can be ordered from
"Technical Assistance":
• Either by e-mail to:
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CLASS 10A
CLASS 10
CLASS 20
CLASS 30
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= Tripping current for protection function L
= Tripping current for protection function I
= Tripping current for protection function R
= Tripping time for protection function R
= Tripping current for protection function U
= Tripping time for protection function U
= Rated operational current of motor
= Starting current of motor
= Peak value of subtransient starting
current
= Starting time of motor
= Duration of subtransient starting
phase
= Typical starting characteristic of the
motor
= Example of a tripping characteristic
for a motor starter protector with
electronic trip unit