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Fault diagnosis

The following table contains the most common fault causes during commissioning and maintenance.

Fault

Possible cause

Action

Power LED does not light up

No power supply connected.

The NRT XT requires 12–24 V DC at terminal POWER.

Power supply connected with reversed polarity.

Observe terminal markings.

The NRT XT cannot be called.

No phone line connected.

A phone line must be connected to terminal LINE (A/B). With supply voltage, the green STATUS LED must flash.

Dialed phone number incorrect

Connect a telephone instead of the NRT. If the phone number is correct, the telephone will ring.

Line is permanently busy

By disconnecting terminal “LINE,” you can check which NRT is occupying the line.

The wrong NRT XT answers.

Incorrect or missing extension digit in multi-device operation.

Check the extension digit (bus address) of the NRT using the PRG 100 or the service button.

The alarm buttons on the voltage-activated inputs are not working.

No power supply connected.

The voltage supplied through the alarm buttons to the voltage-activated inputs must be present and buffered.

None of the connected alarm buttons are working.

Pressing the alarm button activates the wrong speaker/microphone combination.

The assignment of microphones and speakers to the alarm buttons is configured incorrectly.

Alarm filter is active.

The alarm filter is enabled for one or more alarm buttons, and the NRT receives the corresponding signal from the lift controller. As a result, the NRT does not trigger a lift alarm.
For testing purposes, the alarm filter input can be temporarily disconnected.

The NRT keeps dialing, but no connection is established.

If NRT calls a telephone:

  1. The emergency call type is configured incorrectly.

  2. The called party does not acknowledge.

  1. The correct alarm call type must be set using a PRG or telephone command #*72.

  2. The called party must press a digit on their DTMF-capable telephone.

The illuminated pictogram blink alternately.

A timer call from the NRT could not be completed successfully.

  1. Check the power supply of the NRT.
    12–24 V DC are required.

  2. Verify the telephone number for the timer call.

  3. Check whether the telephone line was available at the time of the timer call.

The yellow pictogram indicator stays on.

A stored lift alarm is present in the NRT.

Initiate end of alarm / alert acknowledgment (see “end of alert / alert acknowledgment”).

The piezo buzzer emits beeps once per second for one minute.

The power supply has failed.

Check and restore the power supply.