Rockwell Automation Allen-Bradley E300, User Manual

Page: 142 / 546

142 Rockwell Automation Publication 193-UM015D-EN-P - February 2015
Chapter 6 Protective Trip and Warning Functions
Ground Fault Type
The E300 Electronic Overload Relay has two options available to measure
ground fault current. Ground Fault Type (Parameter 241) allows you to select the
internal option or the external option with the appropriate measurement range.
Table 174 - Ground Fault Type (Parameter 241)
Ground Fault Maximum Inhibit
Ground faults can quickly rise from low-level arcing levels to short circuit
magnitudes. A motor starting contactor may not have the necessary rating to
interrupt a high magnitude ground fault. In these circumstances it is desirable for
an upstream circuit breaker with the proper rating to interrupt the ground fault.
When enabled, Ground Fault Maximum Inhibit (Parameter 248), inhibits a
ground fault trip from occurring when the ground fault current exceeds the
maximum range of the core-balance sensor (approximately 6.5 A).
ATTENTION: The E300 Electronic Overload Relay is not a ground fault circuit
interrupt or for personal protection as defined in Article 100 of the NEC.
ATTENTION: The E300 Electronic Overload Relay is not intended to signal a
disconnecting means to open the faulted current. A disconnecting device must
be capable of interrupting the maximum available fault current of the system
on which it is used.
Ground Fault Type (Parameter 241)
Default Value 1 = Internal 0.500…5.000 A
Range
1 = Internal 0.500…5.000 A
2 = External 0.020…0.100 A
3 = External 0.100…0.500 A
4 = External 0.200…1.000 A
5 = External 1.000…5.000 A
Parameter Type USINT
Size (Bytes) 1
Scaling Factor 1
Units