Rockwell Automation 193-EC1_2_3_5, 193-ECPM,592-EC1_2_3_5 E3 and E3 Plus Solid-State Overload Relay User Manual - Manual (Page 55)

Rockwell Automation Publication 193-UM002I-EN-P - December 2011 55
Protective Trip & Warning Functions Chapter 3
When enabled, GF Trip Inhibit, Parameter 89, inhibits a ground fault trip from
occurring when the ground fault current exceeds the maximum range of the core
balance sensor (approximately 10 A).
Ground Fault Warning
The E3 Plus Overload Relay will indicate a ground fault warning if:
• no warning currently exists,
• ground fault warning is enabled,
• GF Inhibit Time has expired, and
• GF Current is equal to or greater than the GF Warn Level (Series C and
later devices) for a time period greater than the GF Warn Delay.
When the ground fault warning conditions are satisfied, the
• TRIP/WARN LED status indicator will flash an amber 4-blink pattern,
• bit 3 in Warning Status, Parameter 15, will set to 1, and
• bit 1 of Device Status, Parameter 21, will go to 1.
GF Warn Level, Parameter 38, allows the installer to define the ground fault
current at which the E3 Plus Overload Relay will indicate a warning and is
adjustable from 1.0…5.0 A.
In Series C and later, GF Warn Delay, Parameter 105, allows the installer to
define the time period (adjustable from 0.0…25.0 s) for which a ground fault
condition must be present before a warning occurs.
Ground Fault Filter
An E3 Plus Overload Relay with firmware revision 5.00 and higher has the
capability to filter ground fault currents for High Resistance Grounded (HRG)
systems from its current-based protection trip and warning functions. These
filters include: Thermal Overload, Phase Imbalance, Jam, and Stall.
The Ground Fault Filter is useful for smaller-sized motors that trip unexpectedly
due to a controlled ground fault current that is significant relative to the current
draw of the electric motor. GF Filter Enable, Parameter 131, allows the user to
enable this filter.
This filter only disables the effects of the ground fault current from the current-
based motor protection trip and warning functions. Current-based diagnostic
data will be reported unfiltered when this feature is enabled.
IMPORTANT In E3 Plus Overload Relay Series A and B, the ground fault warning
function does not include a time delay feature. Once the GF Inhibit Time
has expired, the ground fault warning indication is instantaneous.