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2 Functions
Figure 2-52
2.24.2 Setting Notes
Motor Starting Time Supervision is only effective and available if address 165
General
STARTUP MOTOR was set to Enabled during configuration. If the function is not re-
quired Disabled is set. Address 6501 STARTUP MOTOR serves to switch the func-
tion ON or OFF or to block only the trip command (Block relay).
Under normal conditions the values of the startup current are entered at address 6502
Pickup Values
START. CURRENT and those of the startup time at address 6503 STARTING TIME.
This ensures timely tripping if the value of I
ceeded.
If the startup time is longer than the permissible blocked rotor time, an external rpm-
counter can initiate the definite-time tripping characteristic via binary input (">Rotor
locked"). A locked rotor leads to a loss of ventilation and therefore to a reduced
thermal load capacity of the machine. For this reason the motor starting time supervi-
sion is to issue a tripping command before reaching the thermal tripping characteristic
valid for normal operation.
A current above the threshold 6505 (address I MOTOR START) is interpreted as a
motor startup. Consequently, this value must be chosen such that it is reliably attained
by the actual starting current under any load or voltage conditions during motor start-
up, but not during a permissible short-time overload.
146
Logic Diagram of the Motor Startup Time Monitoring
2
t calculated by the protection device is ex-
C53000-G1176-C127-3
7UM61 Manual
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