Understanding ETM Trip Unit (Current and Power Ranges)
The ETM trip unit requires
an external 24V DC control power supply to power the display and
enable Modbus communication. Without this control power, neither the LCD
nor the communications will function.
With control power applied, the trip unit will measure and display current values. The exact minimum current threshold that the LCD screen can reliably register has been specified in the documentation.
This image translates
to:
Ammeter display limits:
→ Minimum current ≥ 0.3 × In
Ammeter display limits:
→ Minimum current ≥ 0.3 × In
→ Maximum current ≤ 10 × In
The current meter display range is limited between 30% of the rated current and up to 10 times the rated current.
For ETM products, the minimum measurable current is 0.3 × In.