ABB RELION 620 Series Technical Manual page 618

Hide thumbs Also See for RELION 620 Series:

Table of Contents

Supervision functions

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

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

illustrated in

1MAC504801-IB E

620 series ANSI

Technical Manual

Chapters

Table of Contents