Pulse Rectifier (Embedded in a Test Station)

PSS-PRU pulse rectifier embedded in a test station converts alternating electric current into direct current and supplies the necessary potential to the protected elements. PSS-PRU is one of the most popular variants of the station used in modern cathodic protection systems. The rectifier is an equipment unit consisting of a terminal panel, a control system and a power module. The unit is located inside a rack with sealed hatches for working with equipment.

Functionality

• Provides measurement of the polarization potential.
• Operation in the mode of automatic maintenance of the total or polarization potentials at a given level.
• Operation in the mode of automatic stabilization of the protective current.
• Operation in the mode of automatic stabilization of the output voltage.
• Alarm about the occurrence of a break in the circuit of the reference electrode or potential sensor with automatic transition to the output current stabilization mode, at the level that was before the accident occurred.
• Calculation and indication of the time when the structure is under cathodic protection.
• Counting and indication of the time when the rectifiers are under the voltage of the supply network, in the switched-on state.
• Short circuit protection in the load circuit with automatic switching to operating mode after the short circuit is eliminated.
• Overload, overvoltage and overheating protection.
• Automatic activation in the set mode when the supply voltage disappears and reappears (in case of power outages).
• The possibility of increasing the output power of the rectifier by installing additional power modules.
• The input, measuring and output circuits of the rectifier are protected from pulse overvoltages.
• All information about the output data, operating mode and other parameters of the rectifier is displayed on the LED display.
• The ability to record (archive) the operating parameters of the rectifier (input voltage, output voltage and output current of the rectifier, total and polarization potentials), unauthorized access signals, emergency situations and other signals to a removable SD memory card with a capacity of up to 4 GB installed in the data logger.( This function is not provided as standard, it is discussed when ordering).

It is possible to remotely monitor the operation of the rectifier and control it using embedded adapters via RS-485 MODBUS RTU interfaces, "current loop" and using a GSM modem.

The rectifiers operate in the following modes:
1) automatic maintenance of the total potential at a given level in the range of values from minus 3.5 V to minus 0.5 V;
2) automatic maintenance of the polarization potential at a given level in the range of values from minus 2.0 V to minus 0.5 V;
3) automatic maintenance of the protective current (stabilization of the output current);
4) automatic stabilization of the output voltage.

Calibration of measuring circuits of the rectifier control unit was carried out at the manufacturer. The control unit is used as an indicator of the output parameters and operating modes of the rectifier. To control the correctness of maintaining the set value of the output parameter of the rectifier, it is necessary to use certified external specialized measuring devices of an approved type that are connected to the corresponding terminals of the rectifier.

Remote Monitoring Types

T1 – connection via the "current loop" communication channel with physical signals (analog (4-20 mA) and discrete);
T2 – connection to the rectifier via serial digital interface RS-485, Modbus RTU protocol;
T3 – connection via GSM/GPRS communication channel version 1 (basic);
T4 – connection via GSM/GPRS communication channel version 2 (with two SIM cards);
T5 – connection via GSM/GPRS communication channel version 3 - (standard type of remote monitoring for this rectifier modification);
T6 – connection to the rectifier via a radio channel (in the UHF band or others).

Combinations of remote monitoring types can be implemented into rectifiers. In this case, the designation should be carried out as follows:
T13 – combination of T1 and T3 types
T25 – combination of T2 and T5 types
T124 is a combination of types T1, T2 and T4, etc.