Parker AC890 Product Manual page 358

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
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
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
Determines the rate at which the inverse time current limit is ramped to the AIMING POINT after a period of prolonged
overload.
890SD Standalone Drive - Frames G, H & J
PREF: 162.01
PREF: 162.02
PREF: 162.03
Default: 105.00 %
Default: 4.0 s
Default: 1.0 s
Range: 50.00 to 105.00%
Range: 0.5 to 60.0s
Range: 0.5 to 10.0s
D-67
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