How To Use Monitoring Functions; Mdu Breaker Alarms - Mitsubishi Electric NF400-SEW Instruction Manual

(1) PAL (load current pre-alarm)

The alarm is output to display/over communication when the load current ≥ the pre-alarm current, and the duration ≥

Alarm details

the pre-alarm operating time (1/2 the long time delay operating time (TL)).

Setting method

No settings. (The pick up value set on the MDU Breaker main unit.)

Set to either self-hold or automatic reset via communication or on the display.

Reset method

Reset method

(2) OVER (overcurrent alarm)

The alarm is output to display/over communication when the load current exceeds 105 to 125% of the current setting

Alarm details

of the circuit breaker.

Setting method

No settings.

Reset method

Automatic reset. (No settings.) Automatically resets when the cause of the alarm is removed.

(3) IDM_AL (electric current demand alarm)

Alarm details

The alarm is output to display/over communication when the electric current demand value (*) exceeds the pick up current.

Set via communication or on the display

　 Function: ON/OFF

　 Pick up current: 50 to 100% (per 1%)

Setting method

　 Demand time limit: 1 to 10 min. (per 1 min), 15, 20, 25, 30 min. (*)

Set to either self-hold or automatic reset via communication or on the display.

Reset method

Reset method

* This differs from the demand time limit for each measurement value.

Measurement

value

Pick up current

Self-hold

Automatic reset

(Factory setting is OFF.)

Self-hold

Automatic reset

Alarm generated

Reset the alarm via communication or on the display.

Automatically resets when the cause of the alarm is removed.

Reset the alarm via communication or on the display.

Automatically resets when the cause of the alarm is removed.

Alarm reset

For automatic reset, the alarm will be reset

if the value falls below the pick up current.

For self-hold, the alarm will be maintained

and will need to be reset manually.

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Time