Support Center

Welcome to the Continental Control Systems’ support pages. This section contains articles to assist with installing, configuring, troubleshooting, and using our WattNode meter and current transformer products. Information on other products, accessories, and services that are sold by other companies that work with WattNode products are also list here.

Accu-CT-Logo

Split-Core Current Transformer Standard and Revenue Grade Accuracy

Excellent Linearity
Low Phase Angle Error
0.3% Accuracy Available
UL 2808 (XOBA) Listed
All CTs Are Not the Same!

Oval Window Opening 1.25 x 1.83 in. 250 A, 400 A, and 600 A models

The Patented Accu-CT split-core current transformer technology delivers exceptional linearity and low-end accuracy. Developed specifically for solar inverter, variable speed motor drive, and other applications where there are large variations in current. The measurement range of Accu-CTs is specified from 1% to 120% of rated current, with a phase angel error of only ±0.5°. The low-end accuracy of ACTL Series CTs is ten times better than industry standard CTs. The unique one-handed opening and closing mechanism makes installation a snap. ACTL series CTs are available in both standard and revenue grade accuracy models. Revenue grade models ship with a serialized certificate of calibration. The oval opening can handle a single 750 kcmil (MCM) conductor or two 350 kcmil (MCM) conductors.

  • Safe: burden resistor built-in, 333 mVac voltage output at rated full scale current—no shorting blocks needed!
  • UL 2808 Listed meets 2017 NEC code requirement for field installed CTs
  • IEEE C57.13 and IEC 60044-1 accuracy: over full temperature range and down to below 1% of rated current
  • Exceptionally low phase angle error: essential for accurate power and energy measurements
  • Glove-friendly: easy to open and install with one hand while wearing safety gloves
  • Approvals: CE mark, RoHS
  • Accu-CT Sales Sheet (PDF)
  • ACTL-1250 Datasheet (PDF) – Covers standard (1%) and Opt C0.6 (0.5%) models
  • ACTL-1250 Opt C0.3 Datasheet (PDF) – Covers Opt C0.3 (0.3%) models
  • ACTL-1250 Installation Manual (PDF)

Models

Note: the ACTL-1250 and ACT-1250 models are identical.

Model Rated Amps Type Accuracy Phase MSRP
ACTL-1250-250 250 Standard 0.75% 0.50 deg $56.00 each
ACTL-1250-400 400 Standard 0.75% 0.50 deg $56.00 each
ACTL-1250-600 600 Standard 0.75% 0.50 deg $56.00 each
ACTL-1250-250 Opt C0.6 250 Revenue-Grade 0.50% 0.25 deg $67.00 each
ACTL-1250-400 Opt C0.6 400 Revenue-Grade 0.50% 0.25 deg $67.00 each
ACTL-1250-600 Opt C0.6 600 Revenue-Grade 0.50% 0.25 deg $67.00 each
ACTL-1250-250 Opt C0.3 250 Revenue-Grade 0.30% 0.125 deg $77.00 each
ACTL-1250-400 Opt C0.3 400 Revenue-Grade 0.30% 0.125 deg $77.00 each
ACTL-1250-600 Opt C0.3 600 Revenue-Grade 0.30% 0.125 deg $77.00 each

Performance Graphs

ACTL-1250-250A-600A-Accuracy-Graph.png

ACTL-1250-250A-600A-Phase-Angle-Graph.png

  • Graphs show typical performance at 23°C, 60 Hz
  • Graph shows a positive phase angle when the output leads the primary current.

Specifications

Accuracy

The accuracy specifications apply over the full operating temperature range (-30°C to 55°C) unless otherwise noted. Standard models are calibrated for optimum accuracy at 50-60 Hz. The following accuracy specifications apply to the standard model (no options) or for Option C0.6; the specifications may vary for other options, so see the details on individual options for specifications.

Standard Accuracy

  • Accuracy: ±0.75% from 1% to 120% of rated primary current
  • Phase angle: ±0.50 degrees (30 minutes) from 1% to 120% of rated current
  • IEEE C57.13 accuracy: class 1.2 from 1% to 120% of rated current
  • IEC 60044-1 accuracy: class 1.0 from 1% to 120% of rated current

Opt C0.6 Revenue-Grade Accuracy

With Option C0.6, the Accu-CT is calibrated and verified to meet IEEE/ANSI C57.13-2008 class 0.6 accuracy and IEC 60044-1 class 0.5 S accuracy and each CT is shipped with a certificate of calibration.

  • Accuracy: ±0.50% from 1% to 120% of rated primary current
  • Phase angle: ±0.25 degrees (15 minutes) from 1% to 120% of rated current
  • IEEE C57.13 accuracy: class 0.6 from 1% to 120% of rated current
  • IEC 60044-1 accuracy: class 0.5 and 0.5 S from 1% to 120% of rated current

Opt C0.3 Revenue-Grade Accuracy

With Option C0.3, the Accu-CT is calibrated and verified to meet IEEE/ANSI C57.13-2008 class 0.3 accuracy and IEC 60044-1 class 0.5 S accuracy and each CT is shipped with a certificate of calibration. To achieve this level of accuracy, you must specify C0.3 CTs with Opt 60Hz or Opt 50Hz.

  • Accuracy: ±0.30% from 1% to 120% of rated primary current
  • Phase angle: ±0.125 degrees (7.5 minutes) from 10% to 120% of rated current
  • Phase angle: ±0.25 degrees (15 minutes) from 1% to 10% of rated current
  • IEEE C57.13 accuracy: class 0.3 from 1% to 120% of rated current
  • IEC 60044-1 accuracy: class 0.5 and 0.5 S from 1% to 120% of rated current

Electrical

  • Primary rating: 250 to 600 amps nominal
  • Voltage and Measurement category/
    • 600 Vac, CAT IV (service entrance) for pollution degree 2
    • 250 Vac, CAT III for pollution degree 3
  • Line frequency: 50 to 60 Hz nominal (available for up to 400 Hz)
  • Maximum continuous primary amps: 720 amps
  • Maximum primary conductor gauge: (see Wire Gauges)
    • One 750 kcmil THHN conductor (1.14 inch nominal diameter with insulation)
    • Two 350 kcmil THHN conductors. They must be in close contact to both fit.
  • Output: 333.33 mVac or 1.00 Vac (with Option 1V)
  • Output lead wires:
    • Standard length: 8 ft (2.4 m)
    • Gauge: #18 AWG
    • Type: MTW, UL 1015
    • Voltage: 600 Vac
    • Style: Two conductor: white and black, twisted
  • Internal Burden Resistance: see ACTL-1250 Internal Burden Resistance

Mechanical

ACTL-1250-Dimensions.png

  • Width: 4.50 inches (114.0 mm)
  • Height: 3.30 inches (83.4 mm)
  • Thickness: 1.58 inches (40.2 mm)
  • Window: 1.83 x 1.26 inches (46.5 x 32.0 mm)
  • Weight: 13.9 oz (395 gm)
  • Material: PC/ABS

Miscellaneous

  • Operating temperature: -30°C to 75°C (–22°F to 167°F)
  • Altitude: up to 3000 m (9840 feet)
  • Operating Humidity: 5 to 95% relative humidity (RH)
  • Pollution Degree:
    • 2 (controlled environment) for CAT IV, 600 Vac
    • 3 (harsh environment) for CAT III, 250 Vac
  • Indoor Use: Suitable for indoor use.
  • Outdoor Use: Suitable for outdoor use when mounted in a NEMA 3R or 4 (IP 66) rated enclosure, provided the ambient temperature will not exceed 75°C (167°F).
  • UL listed: file number E363660 (XOBA), standard UL 2808
  • cUL listed (Canada): file number E363660 (XOBA7), standard CAN/CSA C22.2 No. 61010-1
  • CE mark: pending
  • RoHS
  • Assembled in USA
  • Label barcode: QR Code, “Model ; SerialNum”

Options

Opt C0.6

With Option C0.6, the Accu-CT meets IEEE/ANSI C57.13-2008 class 0.6 accuracy and IEC 60044-1 class 0.5 and class 0.5 S accuracy from -30°C to 55°C and from 1% to 120% of rated primary current (see CT Accuracy Standards).

  • Accuracy improves to ±0.5% from 1% to 120% of rated primary current from -30°C to 55°C.
  • Phase angle improves to ±0.25 degrees from 1% to 120% of rated primary current from -30°C to 55°C.
  • Includes a certificate of calibration
    • Order option C0.6,N if you need the C0.6 accuracy, but do not need a certificate of calibration.

Opt C0.3

With Option C0.3, the Accu-CT meets IEEE/ANSI C57.13-2008 class 0.3 accuracy and IEC 60044-1 class 0.5 and class 0.5 S accuracy.

  • Accuracy improves to ±0.3% from 1% to 120% of rated primary current from -30°C to 55°C.
  • Phase angle improves to ±0.125 degrees from 10% to 120% of rated current from -30°C to +55°C.
  • ACTL-1250 models with Opt C0.3 for use on 50 Hz electrical systems should be ordered with option 50 Hz for best accuracy.
  • Includes a certificate of calibration
    • Order option C0.3,N if you need the C0.6 accuracy, but do not need a certificate of calibration.

Opt 60Hz and Opt 50Hz

Except for class 0.3 accuracy models, the ACTL-1250 series of transformers are not available with options to specify operation at 50 or 60 Hz, because it is not needed. The standard models and Opt C0.6 models meet the accuracy specifications over the full range from 50 to 60 Hz. With Opt C0.3, it is necessary to specify Opt 60Hz or Opt 50Hz to achieve the specified phase angle accuracy.

Opt FT

The Accu-CT can be ordered with custom lead lengths. For example, Opt FT=50 for 50 foot leads. We also sell extra lead wire to allow for field extension of the leads. Option FT does not affect the accuracy specifications.

Advanced Options

The Accu-CT advanced options are generally not useful when ordering the Accu-CT for use with a WattNode® meter, but may be useful for other applications.

Safety Note

Warning: Hazardous Voltages – Only qualified personnel or licensed electricians should install the WattNode meter and current transformers.

in ACTL-1250