High Current Protection; Signal Flow Of The High Current Protection Function; Trend Diagram Of The Motor Current Over Time - ABB UMC100.3 Manual

U M C 1 0 0 . 3 U N I V E R S A L M O T O R C O N T R O L L E R T E C H N I C A L D E S C R I P T I O N
42

High Current Protection

This function is useful to protect the driven mechanical system from jams and excessive overloads caused by the equipment or the
process. The high-current function signals a warning when the motor current exceeds a set threshold for a configurable period of
time, after the motor start-up. The high current function creates a trip when the current continuously exceeds a separately set
threshold for a set period of time, after the motor start-up.
Block diagram:
I>I
hcwl
I/I [%]
e
I>I
hctl
After Start-up
—

Signal flow of the high current protection function.

Example:
The start-up phase ended at T1. At T2 the current increases above the high current warning level I
high current warning delay time t
high current trip level I but only for a period shorter than the specified high current trip delay time t
hctl
rises again above the trip level and stays there long enough to trigger an overcurrent trip that finally stops the motor.
I/I [%]
e
I
hctl
I
hcwl
I
SE
I
e
High Current Warn
T1
High Current Trip
---------------------------------------/===========================================================
-------------------------------------------------------------------------------/===================
—

Trend diagram of the motor current over time

It shows the function of the high current protection function with the related parameters.
Relevant Parameters:
• High Current Trip Level
• High Current Trip Delay
& T
hcwd
& T
hctd
. Therefore the high current warning signal is set. At T3 the current also increases above the
hcwd
T3
T2
t
hcwd
t
hctd
• High Current Warning Level
• High Current Warning Delay
High Current
Warning
High Current
Trip
T4
t
hctd
for a period longer than the
hcwl
. Then at T4 the current
hctd
I : High current trip
hctl
delay time
I : High current warning
hcwl
delay level
I : High current trip delay
hctd
I : High current warning
hcwd
delay
I : Nominal current
e
I : Current defining
SE
the end of the start-
up period
t