equal to or greater than
Motor standstill A
, the
MOT_START
output signal is activated
indicating that the motor start-up 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
start-up situation is over.
GUID-4475BDFB-57AE-4BFD-9EE7-AE7672F7206E V2 EN
Figure 377:
Functionality of start-up supervision in the "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
start-up 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.
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 start-up is recognized.
The motor start-up ends either within the value of the
Str over delay time
setting from the
beginning of the start-up 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
.
Section 4
1MAC059074-MB A
Protection functions
752
615 series ANSI
Technical Manual
Summary of Contents for Relion 615 series
Page 1: ... RELION PROTECTION AND CONTROL 615 series ANSI Technical Manual ...
Page 2: ......
Page 39: ...Section 17 Glossary 1181 Table of contents 615 series ANSI 33 Technical Manual ...
Page 40: ...34 ...
Page 64: ...58 ...
Page 216: ...210 ...
Page 884: ...878 ...
Page 1038: ...1032 ...
Page 1136: ...1130 ...
Page 1172: ...1166 ...
Page 1180: ...1174 ...
Page 1186: ...1180 ...
Page 1192: ...1186 ...
Page 1193: ...1187 ...
Page 1194: ......
Page 1195: ......
