Device 37 - Fixed Pickup Undercurrent; Table 6-5 Advanced Motor Protection Menu - Fixed Pickup Undercurrent Device (Id 7256) - Siemens SINAMICS PERFECT HARMONY GH180 Function Manual

6.6

Device 37 - Fixed Pickup Undercurrent

Overview
Fixed pickup undercurrent is used to protect the motor against operation with RMS phase
currents that are below the desired level. The fixed pickup undercurrent function provides an
RMS phase current setting that produces a trip or alarm condition when the current falls below
that value. The function can be programmed to produce a trip or an alarm when any one, any
two, or all three of the phase currents (Phase A, Phase B, Phase C RMS currents) is below the
set point. The function offers a minimum speed enable that only allows activation of this function
after the programmable minimum speed has been reached. Once the minimum speed has
been reached, the function remains enabled regardless of speed until the drive stops or the
demand is set to a value below the minimum speed reset. The minimum speed reset is used to
define a range of demand settings below which the function will remain in a reset condition. The
per-unit speed protection variable may be derived from a flux based Phase Locked Loop (PLL)
or encoder.
Note
Encoder Loss
Depending upon the value of parameter 1320 (encoder loss response), when a loss of the
encoder occurs, the drive will either default to the phase locked loop to obtain motor speed
information or the drive will stop.
Device 37 provides parameter status as shown in table
Fixed Pickup Undercurrent .
Table 6-5 Advanced Motor Protection Menu - Fixed Pickup Undercurrent Device (ID 7256)
Keypad Parameter Text
Tool Parameter Text
Pickup Level
Fixed Under Current Pickup Level
Pickup Delay
Fixed Under Current Pickup Delay
Dropout Level
Fixed Under Current Dropout Level
Dropout Delay
Fixed Under Current Dropout Delay
Low Pass Time Constant
Fixed Under Current Low Pass Time Constant
Minimum Speed Enable
Fixed Under Current Enable Point
Startup Time
Fixed Under Current Delay from Startup
Advanced Motor Protection for Variable Speed Operation
Manual, AA, A5E46373908A
Advanced Motor Protection and RTD Protection Functions
6.6 Device 37 - Fixed Pickup Undercurrent
Advanced Motor Protection Menu -
ID Units
7257 %
7258 sec
7259 %
7260 sec
7261 msec
7262 %
7263 sec
Default Minimum - Maximum
Value Value
5 0 - 100
1 0 - 180
102 100 - 200
0.1 0 - 180
0 0 - 1000
20 0 - 100
5 0 - 200
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