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Rogowski coil flexible CTs are ideal for applications where regular rigid current transformers cannot not fit. The RCSL (small) and RCLL (large) diameter Rogowski current sensors are flexible loops that open for easy installation around a conductor or sets of phase conductors, or bus bars. Rogowski coil flexible CTs are available in five diameters with rated currents from 200 to 5000 amps up to 600 volt. This family of Rogowski coils are used in 120/240 volt residential solar monitoring applications and high-current three-phase industrial and commercial building.

The RCxL series of Rogowski coil flexible CTs have a coil junction housing that holds the ends of the coil together, contains the conditioning circuitry, and connects the output cable to the WattNode power meter or other power meters that require 0.333 Vac current transformers. Coils are supplied with 8 ft. (2.4 m) long four conductor shield cable to connect to the power meter and a 12 volt DC power supply. The internal signal conditioning circuit eliminates the need for an external module making installation easy.

Installing a power meter in a home with a combination meter breaker panel can seem impossible because there is no space for traditional rigid CTs. The model RCSL coil, with an end cap diameter of only 0.408 inch (10.35 mm) is the ideal solution.




  • Safe0.333 Vac output—no need for shorting blocks!
  • Flexible coil for easier installation
  • Built-in signal conditioning circuit
  • Rated currents: from 200 to 5000 amps
  • Opening diameters: 1.5 to 11.8 inches (40 to 300 mm)
  • Shielded coil and cable for noise immunity
  • Excellent linearity and low phase angle error
  • UL Listed CAT IV, 600 Vac, service entrance CE Mark, RoHS


RCLL-4.7-1000 Typical Accuracy

Rogowski coil flexible current transformers


RCSL and RCLL models of Rogowski coil flexible current transformers

RCSL-1.5-0200 200 400 1.5 in (40 mm)
RCSL-3.1-0250 250 2000 3.1 in (80 mm)
RCSL-3.1-0600 600 2000 3.1 in (80 mm)
RCSL-3.1-1000 1000 2000 3.1 in (80 mm)
RCLL-4.7-1000 1000 2000 4.5 in (120 mm)
RCLL-4.7-2000 2000 2000 4.5 in (120 mm)
RCLL-7.8-1000 1000 5000 7.8 in (200 mm)
RCLL-7.8-2000 2000 5000 7.8 in (200 mm)
RCLL-11.8-5000 5000 5000 11.8 in (300 mm)
Table 1: RCSL and RCLL Rogowski Coils

Rated Amps is the nominal measurement range, which can be extended to 120% of the rated current of the coil.

Max Safe Amps is the maximum continuous current that will not damage the Rogowski coil flexible CTs.



  • Output signal accuracy from 50 to 60 Hz at 77°F (25°C)
    • Accuracy (% of reading): ±1.0% from 3% to 120% of rated current
    • Typical Phase Angle Error: ±0.10 degrees (6 minutes) from 3% to 120% of rated current
    • Maximum Phase Angle Error: ±0.20 degrees (12 minutes) from 3% to 120% of rated current
  • Temperature Sensitivity:
    • Accuracy: additional ±0.5% error over operating temperature range
    • Phase Angle: no added error over operating temperature range
  • Conductor Position and Orientation Sensitivity: typical ±0.5%, maximum ±1.0% The quoted gain accuracy is with the measured conductor centered in the coil opening and perpendicular to the coil. Moving the conductor off-center or tilting the coil will reduce the accuracy. The phase angle varies by less than 0.01 degrees at varying positions and orientations.


  • Nominal Line Frequency: 50 to 60 Hz
  • Max Safe Continuous Primary Current: see Table 1 above.
  • Maximum Voltage: 600 Vac
  • Overvoltage and Measurement Category:
    • 600 Vac, CAT IV (service entrance) for pollution degree 2
  • Output Cable:
    • Length: 8 ft (2.4 m)
    • Conductor Wire Gauge: #24 AWG (0.25 mm2)
    • Voltage: 600 Vac
    • Temperature Rating: 221°F (105°C)
    • Style: AWM, shielded, four-conductor, twisted, white/black/red/blue
    • Input Polarity: red = positive, blue = common (negative)
  • DC Operating Power Supply:
    • Input Voltage Range: 3.5 Vdc to 13.5 Vdc
    • Input Current: 6 mA typical, 20 mA maximum (excluding short-circuits of the output leads)
  • Output Signal: 0.33333 Vac nominal with 1.25 Vdc bias relative to DC supply common (blue)
    • Polarity: white = current transformer positive (in-phase with current) signal, black = current transformer negative (180 degree phase to current) signal
  • Expected Load Resistance: (see Effect of Output Loading section below): 23k ohms

Power Supply

  • HDR-15-12
    • Make: Mean-Well
    • Type DIN-rail mount supply (DIN rail TS-35/7.5 or 15)
    • AC Input Voltage: 85 – 264 Vac, 100 – 240 Vac nominal
    • Input Frequency: 47 – 63 Hz
    • Operating Temperature: -22°F to 158°F (-30°C to 70°C) full load at 50°C, 50% load at 70°C
    • Input Current: less than 0.5 A RMS typical
    • Output Voltage: 5 Vdc, ±2.0%
    • Output Current: 2.4 amps (this is sufficient to power at least 50 sensors)
    • Maximum Output Power: 15 watts
    • Emissions: CISPR22 class B
    • Features: No minimum load, over-voltage protection, overload protection, short-circuit protection
  • Alternate Supplies: Other power supplies may also be used, provided the output meets the DC Operating Power Supply specifications given above.
Rogowski coil wiring diagram


  • UL: UL listed, XOBA, UL 2808, CAN/CSA C22.2 No. 61010-1-12, 3rd Edition, E363660
  • RoHS compliant


  • Operating temperature:
    • RCSL-1.5 and RCSL-3.1: –40°F to 167°F (–40°C to +75°C)
    • RCLL-4.7: –40°F to 167°F (–40°C to +75°C)
    • RCLL-7.8 and RCLL-11.8: –40°F to 140°F (–40°C to +60°C)
  • Operating humidity: Non-condensing, 0 to 95% relative humidity (RH)
  • Operating Altitude: Up to 6562 feet (2000 m)
  • Pollution Degree: 2; controlled environment
  • Indoor use: Suitable for indoor use.
  • Outdoor use: Suitable for outdoor use when mounted in a NEMA 3R or 4 (IP 66) rated enclosure.


  • RCSL Mechanical:
    • Coil End Cap Diameter: 0.408 in (10.35 mm)
    • Housing Material: Polycarbonate (PC), UL 94 V-0 flame rating
    • Coil Jacket Material: Thermoplastic vulcanizate (TPV), UL 94 V-0 flame rating
  • RCLL Mechanical:
    • Coil End Cap Diameter: 0.443 in (11.25 mm)
    • Housing Material: Polycarbonate (PC), UL 94 V-0 flame rating
    • Coil Jacket Material: Thermoplastic vulcanizate (TPV), UL 94 V-0 flame rating


Limited 5 year warranty. See manual for details.

WARNING: This product can expose you to chemicals including Antimony Trioxide, which is known to the State of California to cause cancer. For more information go to:

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