Pipeline systems and technologies

Resistance control unit

1. Resistance control unit RCU(R)

Produced in two versions:

RCU(R) in the cabinet

Application of the power resistors allows to adjust the channels resistance smoothly without using electrical jumpers and disconnecting the cathodic protection rectifier.

A built-in measuring shunt allows to determine the channel current rate with help of a millivoltmeter.

RCU(R) protection against lightning overvoltage is provided by static protection device (varistor).

Technical specifications
Max. current Adjustment range of the rheostat electrical resistance Quantity of adjustment channels
     
0…30 Ohm 1…n
10А 0…0,5 Ohm 1…n
14А 0…0,5 Ohm 1…n
25А 0…0,25 Ohm 1…n
34А 0…0,25 Ohm 1…n

RCU(R) on the terminal block

Application of the power resistors allows to adjust the channels resistance smoothly without using electrical jumpers and disconnecting the cathodic protection rectifier.

A built-in measuring shunt allows to determine the channel current rate with help of a millivoltmeter.

Four-channel RCU-14A Four-channel RCU-14A
Technical specifications
Max. current Adjustment range of the rheostat electrical resistance Quantity of adjustment channels
     
0…30 Ohm 1…4
10А 0…0,5 Ohm 1…4
14А 0…0,5 Ohm 1…4
25А 0…0,25 Ohm 1
34А 0…0,25 Ohm 1

2. Electronic resistance control unit (ERCU)

ERCU Application field - Corrosion Protection Systems of Metal Structures 

ERCUs are used in combined cathodic protection systems and depending on the version, may ensure simultaneous protection of several buried metal structures from one cathodic protection rectifier by distributing output current among protected structures and setting optimal protection current or potential for each protected structure separately.

The ERCU does not contain any built-in power supplies. The unit is powered by the potential difference between the protected structures.

The ERCU supports the following operation modes:

  • current stabilization mode;
  • potential difference stabilization mode.

ERCU legend

  1. product name;
  2. manufacturer name;
  3. nominal current;
  4. nominal potential difference;
  5. climatic version (U2).

An example of the ordered ERCU-PST with the nominal output current of 30 A and the nominal potential difference of 15 V: ERCU-PST-30-15-U2 TU
 

Basic technical characteristics

Technical characteristics Value
Maximum power dissipation, W 150
Stabilized current range, A 0,5…30 1 
Maximum current within 10 minutes, A 32 2 
Minimum potential difference in the current stabilization mode, V 0,1 3 
Maximum potential difference in the current stabilization mode, V 15 4
Maximum stabilization error of the set current, % 2,5 5
Stabilized potential difference range, V 0,5…12
Maximum stabilization error of the set potential difference, % 2,5
Minimum potential difference for operation of the built-in indicator, V 0,4
Surge protection response voltage, V 16
Maximum voltage and current indication error, % 5
Overheating protection response temperature, °С + 70 6
Maximum reverse voltage, V 100
Maximum reverse current, A  
Climate version as per GOST 15150, in this case: U2
— operating temperature range, °С - 45… + 60 7
— relative air humidity at  25 °С, % up to 98
— atmospheric pressure, kPa from 84,0 to 106,7
— operation in the following types of atmosphere I и II
Minimum transportation and storage temperature, °С - 50
Housing dimensions (without the radiator), mm, max. 255х146х83
Dimensions (with the radiator8 and control elements), mm, max. 600х170х110
Weight, kg, max. 4

 

  1. In case the potential difference at the ERCU terminals is at least 250 mV, the radiator temperature does not exceed 70° С, and the power dissipation does not exceed 150 W.
  2. In case the potential difference at the ERCU terminals is at least 270 mV, the radiator temperature does not exceed 70° С, and the power dissipation does not exceed 150 W.
  3. With the specified potential difference value at the ERCU terminals, the current adjustment is possible up to 2 A; with the voltage of 0.15 V, up to 10 A; and with the voltage ranging from 0.25 V to 15 V, up to 30 A.
  4. In case the radiator temperature does not exceed 70° С, and the power dissipation does not exceed 150 W.
  5. In the range of the potential difference at the ERCU terminals from 0.25 V to 15 V, and absence of protection operation impact.
  6. The radiator temperature is controlled in immediate vicinity of load-bearing elements. Peripheral areas of the radiator may have lower temperature.
  7. As the ambient temperature increases, the maximum possible current and the maximum possible power dissipation of the ERCU will automatically lower to values at which the radiator temperature does not exceed 70 °C.
  8. The ERCU radiator may have different dimensions depending on the operating conditions, upon request and agreement with the Customer.