Rockwell Automation SMC-Flex, User Manual

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1-16 Product Overview
Ground Fault Trip
The SMC-Flex will trip with a ground fault indication if:
• No other fault currently exists
• Ground fault protection is enabled
• GF Inhibit Time has expired
• GF Current is equal to or greater than the GF Trip Level for a
time period greater than the GF Trip Delay
Parameter 75, Gnd Flt Inh Time, allows the installer to inhibit a
ground fault trip from occurring during the motor starting sequence
and is adjustable from 0…250 seconds.
Parameter 74, Gnd Flt Delay, allows the installer to define the time
period a ground fault condition must be present before a trip occurs. It
is adjustable from 0.1…250 seconds.
Parameter 73, Gnd Flt Level, allows the installer to define the ground
fault current at which the SMC-Flex will trip. It is adjustable from
1.0…5.0 A or 5.0…25 A, depending on the service size.
Important: The ground fault inhibit timer starts after the maximum
phase of load current transitions from 0 A to 30% of the
device’s minimum FLA Setting or the GF Current is
greater than or equal to 0.5 A. The SMC-Flex does not
begin monitoring for a ground fault condition until the
Gnd Flt Inh Time expires.
Ground Fault Alarm
The SMC-Flex will indicate a Ground Fault Alarm if:
• No warning currently exists
• Ground fault alarm is enabled
• GF Inhibit Time has expired
• GF Current is equal to or greater than the Gnd Flt A Lvl
Parameter 77, Gnd Flt A Lvl, allows the installer to define the ground
fault current at which the SMC-Flex will indicate a warning. It is
adjustable from 1.0…5.0 A or 5.0…25 A, depending on the service
size.
Parameter 78, Gnd Flt A Dly, allows the installer to define the time
period a ground fault alarm condition must be present before a trip
occurs. It is adjustable from 0…250 seconds.