Underload protection – Rockwell Automation 592- E300 Overload Relay User Manual User Manual
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Rockwell Automation Publication 193-UM015B-EN-P - June 2014
101
Protective Trip and Warning Functions Chapter 5
Jam Warn Level
Jam Warn Level (Parameter 254) allows the user to define the current at which
the E300 Electronic Overload Relay will indicate a warning. It is user-adjustable
from 50…600% for the FLA Setting (Parameter 171).
Table 84 - Jam Warning Level (Parameter 254)
Underload Protection
Motor current less than a specific level may indicate a mechanical malfunction in
the installation, such as a torn conveyor belt, damaged fan blade, broken shaft, or
worn tool. Such conditions may not harm the motor, but they can lead to loss of
production. Rapid underload fault detection helps to minimize damage and loss
of production.
The E300 Electronic Overload Relay can monitor for this condition with its
Underload Trip and Warning function to detect for a rapid underload fault to
minimize damage and loss of production.
Underload Inhibit Time
Underload Inhibit Time (Parameter 255) allows the installer to inhibit an
underload trip and warning from occurring during the motor starting sequence. It
is adjustable from 0…250 s.
Table 85 - Underload Inhibit Time (Parameter 255)
Default Value
150
Minimum Value
50
Maximum Value
600
Parameter Type
UINT
Size (Bytes)
2
Scaling Factor
1
Units
%FLA
IMPORTANT
The Jam Warning function does not include a time delay feature. Once the Jam
Inhibit Time has expired, the Jam Warning indication is instantaneous.
Default Value
10
Minimum Value
0
Maximum Value
250
Parameter Type
USINT
Size (Bytes)
1
Scaling Factor
1
Units
Sec