Parker AC890PX Series, Product Manual

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D-67
Programming
AC890PX AC Drive
INVERSE TIME PMAC
SETUP::MOTOR CONTROL::INVERSE TIME PMAC
Designed for PMAC control mode.
The purpose of the inverse time is to automatically reduce the drive current limit in response to prolonged overload
conditions for drive and motor protection.
As the drive current exceeds the AIMING POINT level, the excess current is integrated. Motor current is allowed to flow up
to
INVERSE TIME OP
for a period defined by the
DELAY
parameter. At this point the inverse time current limit is ramped
down to the AIMING POINT . The rate at which the current limit is ramped to the AIMING POINT is defined by DOWN
TIME
.
Once the overload condition is removed, the inverse time current limit is ramped back to the normal
INVERSE TIME OP
at
a rate determined by the UP TIME .
Parameter Descriptions
AIMING POINT
PREF: 162.01 Default: 105.00 % Range: 50.00 to 105.00%
Determines the final level of the inverse time current limit after a period of prolonged motor overload as a percentage of the
stack rated current.
DELAY
PREF: 162.02 Default: 4.0 s Range: 0.5 to 60.0s
Overload duration before inverse time current limit action is taken. This value is based on INVERSE TIME OP under normal
conditions. Time is reduced to 25% of DELAY if the drive speed is lower than 2.5 (electrical) Hz.
DOWN TIME
PREF: 162.03 Default: 1.0 s Range: 0.5 to 10.0s
Determines the rate at which the inverse time current limit is ramped to the AIMING POINT after a period of prolonged
overload.