Measured Ground Fault

Description

Measured ground fault is more accurate than calculated ground fault, it is calculated with the help of external core balanced current transformer. In normal conditions, the ground current is negligible or null. It is present only when a ground-trip occurs.

DANGER
IMPROPER TRIP DETECTION Measured ground fault protection function will not protect people from harm caused by ground current. Measured ground fault pickup setting must be set to protect the motor and related equipment. Measured ground fault settings must conform to national and local safety regulations and codes. Failure to follow these instructions will result in death or serious injury.

The measured ground-fault protection function generates the following signals:

Alarm: Measured ground current goes above the alarm level.
Trip: Measured ground current goes above the pickup level for the specified time delay.

The protection function can be disabled when the motor is in Start state, to avoid nuisance tripping.

NOTE: Hysteresis is not applicable for measured ground current by setting less than 10% of FLC.

Parameter Setting

The measured ground fault protection function has the following configurable settings:

Parameter	Setting range	Default value
Function	Disable Alarm Trip Alarm + Trip	Disable
Pickup	20–20000 mA in step of 10 mA	30 mA
Time Delay	0.1–6000.0 s in step of 0.1 s	0.1 s
Alarm Level	20–20000 mA in step of 10 mA	30 mA
Reset Mode	Reset key DI Communication Auto	DI + Reset Key
Auto-Reset Delay (applicable only if Reset mode is Auto)	0.0–6000.0 s in step of 0.1 s	0 s
Function While Motor Starting	Disable Enable	Disable