AZT-9
4
ZPrAE Sp. z o.o.
2.6. Signalling LEDs and signal description fields.
In this part of the front panel there are 8 signalling LEDs with description fields for
identification with a suitable signal name. Multicolour super-bright RGB LEDs function as
optical indicators. It is possible to use the software supplied with the AZT-9 protection
device (or the control buttons) to select the signals from the list available in the program.
The LED colour can also be selected from the available range: yellow, red, green, blue,
purple. Next to the LEDs there are description fields. A description field for one LED is 42
mm × 10 mm (W×H). Signal descriptions can be printed on foil or paper and inserted
under the transparent part of the front panel.
2.7. Rear panel and modules.
Fig. 2.4. Rear panel.
Card connectors for external connections are located on the rear panel. LgY cables
are recommended for external connections. The protection device has current and binary
inputs, contact outputs, power supply and external communication connectors. The output
sending the impulse to the switch off coil is separate and specially marked. The impulse is
generated with the energy from the energy storage.
WARNING! The energy storage is normally fully charged; therefore the module can
be energized with 300 V DC even when the device is not connected to any power supply!
3. OPERATING PRINCIPLE.
The device is to be used for protecting transformers, outgoing feeders and busbars
as a backup for primary protection devices.
The core function of AZT-9 is to provide delayed overcurrent phase (51P) and
earth-fault protection (51N). In emergencies, if the primary protection devices do not shut
off the overcurrent, the AZT-9 will generate a shutdown impulse using its own energy
storage after a set delay. The AZT-9 does not require an additional auxiliary power supply
to initiate the shut off impulse because it can be powered by measuring current
transformers. The BAT-1 energy storage can store energy for several weeks allowing the
device to be ready quickly in case of emergencies. If the energy storage is charged before
a disturbance occurs the time required to start up the device and prepare it for operation is
