
Section 6
1MAC050144-MB C
Supervision functions
462
615 series ANSI
Technical Manual
equal or greater than the
Motor standstill A
, the
MOT_START
output signal is activated
indicating that the motor startup is in progress. The
MOT_START
output remains active
until the values of all three phase currents drop below 90 percent of the set value of
Start
detection A
and remain below that level for a time of
Str over delay time
, that is, until the
startup situation is over.
Figure 246:
Functionality of startup supervision in "IIt and IIt&stall" mode
In case of the “IIt, CB” or “IIt & stall, CB” modes, the function initially recognizes the
de-energized condition of the motor when the value of all three phase currents is below the
value of the
Motor standstill A
setting for 100 milliseconds. The beginning of the motor
startup is recognized when CB is closed, that is, when the
CB_CLOSED
input is activated
and at least one phase current value exceeds the
Motor standstill A
setting.
But in normal practice, these two events do not take place at the same instant, that is, the
CB main contact is closed first, in which case the phase current value rises above 0.1 pu
and after some delay the CB auxiliary contact gives the information of the
CB_CLOSED
input. In some cases, the
CB_CLOSED
input can be active but the value of current may not
be greater than the value of the
Motor standstill A
setting. To allow both possibilities, a
time slot of 200 milliseconds is provided for current and the
CB_CLOSED
input. If both
events occur during this time, the motor startup is recognized.
The motor startup ends either within the value of the
Str over delay time
setting from the
beginning of the startup or the opening of CB or when the
CB_CLOSED
input is
deactivated. The operation of the
MOT_START
output signal in this operation mode is as
illustrated
This CB mode can be used in soft-started or slip ring motors for protection against a large
starting current, that is, a problem in starting and so on.
Содержание 615 Series ANSI
Страница 1: ...Relion Protection and Control 615 series ANSI Technical Manual ...
Страница 2: ......
Страница 29: ...1MAC050144 MB C Section 615 series ANSI 22 Technical Manual ...
Страница 389: ...Section 4 1MAC050144 MB C Protection functions 382 615 series ANSI Technical Manual ...
Страница 485: ...Section 6 1MAC050144 MB C Supervision functions 478 615 series ANSI Technical Manual ...
Страница 635: ...Section 10 1MAC050144 MB C Other functions 628 615 series ANSI Technical Manual ...
Страница 707: ...Section 15 1MAC050144 MB C Applicable standards and regulations 700 615 series ANSI Technical Manual ...
Страница 711: ...Section 16 1MAC050144 MB C Glossary 704 615 series ANSI Technical Manual ...
Страница 712: ......