Area of application

iZAZ300 is a series of powerful, communication-enabled, multifunctional digital protection relays with up to 8 measurement inputs. These devices are characterised by high accuracy and reliable operation. They can be used in automatic control systems as advanced and functional power, voltage, current, frequency and earth-fault protection devices. Automatic controls for automatic frequency load shedding, automatic reclosing, automatic voltage load shedding as well as breaker failure protection are supported in applicable hardware and software configurations. This device can be also used as a supplement for generator or generator-transformer block protection. Apart from the protection and automatic control functions, the devices enable measurements, recording, emergency control and signalling. RS-485 serial port and mini-USB port may be used for communication with the relay. Components of the device are installed in an aluminium enclosure suitable for flush-mounting. If mounting on the panel is required, an ANT300 adapter shall be used.

The universal hardware and software enable easy and intuitive changing of the configuration and adaptation to various facilities. With the application base developed by the manufacturer, default solutions can be used. Moreover, it is possible to modify the configuration to match the specifics of the protected facility, and the user needs. The modification of the configuration can include adding protective functions or automatic controls and the change of logic-time dependencies (e.g. means of controlling diodes on the panel, signalling on the display, controlling signalling relays and means of emergency control).

The iZAZ300 relay was adapted to work with the flash sensor for arc protection.


The device is equipped with three different recorders enabling the analysis of phenomena occurring in the protected facility.

Event recorder – basic status recorder creating a chronological event log with a resolution of 1 ms. Circular buffer with a capacity of 500 events. It records protective device excitations, reactivations and operations as well as status changes of binary inputs, automatic controls, and other events generated from the internal logic. Names and comments can be edited for all events, which allows application adaptation and facilitates the analysis of events by the user.

Actuation recorder – enables quantitative analysis of the interferences. This recorder allows the review of interference time and threshold parameters of analogue signals measured from the moment of excitation to the reactivation of the function after its operation. The type and amount of recorded data depend on the nature of the function, e.g. for overcurrent protection it is the interference duration and maximum current value in this period. This recorder enables quick assessment of the event by presenting information on criterion values associated with the interference, giving the user the opportunity to verify settings. For a typical record of three analogue values (e.g. maximum current, voltage), the internal buffer allows recording up to 60 records in the circular buffer.

Disturbance recorder – a set of recorders of analogue and binary waveforms with criterion recorder function enabling full analysis of interfering phenomena. The device allows programming of one or two fully independent configurable recorders. The function of criterion recorder offers the opportunity of recording any of the criterion values available in the device (analogue and binary). The standard settings of pre-run, post-run and maximum recording time enable proper shaping of the log window for the phenomenon of interest. In order to optimize the recording of long term low-frequency phenomena, it is possible to lower the sampling rate with the option of controlling rarefaction of the recorder log using a chosen binary signal (e.g. circuit-breaker open, start-up status, etc.). The capacity of the internal buffer depends on the number of active recorders, programmed analogue and binary channels, and the maximum duration of the individual recording. For a single recorder, a single analogue channel, and 16 binary channels it is possible to record a 280-second file.

Functional characteristics

  • An extensive set of protective functions and automatic controls
  • Extensive list of available measurements, such as measurement of all currents and voltages, and calculated values (e.g. power and energy, frequency, temperature from the model)
  • Programmable controller with a legible graphic interface enabling the implementation of various logic-time dependencies on the basis of all signals available in the device
  • Counters enabling diagnostics of the working status of the bay (including: number of protection device operations, automatic control operations, trips, cumulated counter of circuit-breaker currents)
  • Operation logic easily programmable using a graphic interface
  • Recorder of configurable and system events
  • Actuation recorder
  • Up to 8 measuring inputs (hardware-configurable)
  • 12 output relays, including 11 fully programmable ones, and an efficiency signalling relay
  • 9 programmable binary inputs for use with external protection devices, for interlocks or external signal cancelling
  • 8 programmable signalling diodes on the front panel
  • Extended autotest system with warning signalling
  • Real time clock with sync capability
  • Communication with a PC or parent system via an RS-485 interface and a standard mini-USB port on the front panel
  • Control panel with an alphanumeric 2×16 LCD display and a simplified keyboard on the front panel for basic control of the device
  • Standard package of application software - iZAZ Tools (including iREC software for disturbance recordings analysis)
  • Digital technology ensuring high stability, accuracy and reliability of operation
  • Protection against unauthorised access (setting or configuration modification)