ABB UMC100.3, Руководство пользователя

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[%]
t
I/I
e
I
hctl
I
hcwl
I
e
T1
I
SE
---------------------------------------/===========================================================
-------------------------------------------------------------------------------/===================
T2
T3
t
hcwd
t
hctd
t
hctd
T4
&
I/I
e
[%]
I>I
hcwl
T
hcwd
High Current
Warning
After Start-up
I>I
hctl
& T
hctd
High Current
Trip
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:
—
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
hcwl
for a period longer than the
high current warning delay time t
hcwd
. Therefore the high current warning signal is set. At T3 the current also increases above the
high current trip level I
hctl
but only for a period shorter than the specified high current trip delay time t
hctd
. Then at T4 the current
rises again above the trip level and stays there long enough to trigger an overcurrent trip that finally stops the motor.
—
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 • High Current Warning Level
• High Current Warning Delay
High Current Warn
High Current Trip
I
hctl
: High current trip
delay time
I
hcwl
: High current warning
delay level
I
hctd
: High current trip delay
I
hcwd
: High current warning
delay
I
e
: Nominal current
I
SE
: Current defining
the end of the start-
up period
42 U MC10 0. 3 U N IVE R SA L MOTOR CONTROLLE R T EC H N I C A L D E S C R I P T I O N