Supports Current Measurement of Inverters with High Current and High Speed

Hioki's pass-through type AC/DC current sensors can be connected directly to Hioki Power Analyzers and Memory HiCorders. Also, it can be connected to Power Meters, Oscilloscopes, DMMs, etc. by using an optional sensor unit.
The CT6877A has a frequency bandwidth of DC to 1 MHz and a rated current of 2000 A. It can easily handle large current measurements of electric vehicles such as EVs and HEVs. The CT6877A is also used for R&D, quality evaluation, manufacturing, and maintenance in markets such as wireless charging systems, inverter motors for industrial equipment, power conditioners for PV, and quick charging facilities for EVs.

Use with an instrument with a high input impedance of 1 MΩ or higher.

Key Features

  • Combined accuracy with HIOKI power analyzer PW8001, PW6001 and PW3390 is specified. For details of combined accuracy, refer to the instruction manual.
  • Measures high-current up to 2000 A for EV, HEV and other electric vehicles
  • Improved noise resistance performance through a stronger shield lets you accurately measure current buried in noise
  • High accuracy measurement realized through flat frequency characteristics and CMRR performance
  • More enhanced environmental resistance performance than ever before lets you measure in -40 to 85°C situations
  • Superior frequency characteristics of DC to 1 MHz (amplitude)
  • Meet a wide range of applications from measuring battery charge/discharge to the secondary side of inverters in photovoltaic power generation and fuel cell evaluation, etc. 
  • Monitor waveforms when paired with oscilloscopes or Memory HiCorders and Sensor Unit

Model No. (Order Code)

CT6877A Cable length: 3 m (9.84 ft.)
CT6877A-1 Cable length: 10 m (32.81 ft.)

For applications in EV and HEV testing

Most large currents are divided into two to four wires. In the past, it was necessary to measure wires individually using multiple current sensors due to the devices’ insufficient aperture size and current ratings. The optional Sensor Unit CT9557 provided functionality for adding together the sensors’ measured values in such setups and outputting the result as a single signal.

Collectively measure wires carrying up to 2000 A

Thanks to its large, 80 mm aperture, the CT6877A can accommodate four wires with an outer diameter of 31 mm (equivalent to a cross-sectional area of 250 mm^2). In this way, a single sensor can be used to collectively measure wires carrying up to 2000 A.

Unparalleled technology driving the evolution of current measurement

High-accuracy sensors uses the "zero flux method (flux gate detection type)." High-frequency currents are detected with the winding (CT method), and DC to low frequency currents are detected using a "flux gate."


Flux gate detection

Flux gate detection delivers outstanding linear properties, and can measure currents of a wide range of magnitudes with high accuracy.
The fluxgate components used for DC detection have very low offset over a wide temperature range due to their operating principle, resulting in high accuracy and excellent temperature stability. It is ideal for measurements that require high accuracy, such as Power analyzers and Power meters. It can be used for measurement such as inverter efficiency, inverter output power, reactor/transformer loss, and long-term DC measurements.

Wide frequency band

The CT6877A has a frequency bandwidth of DC to 1 MHz, which is top-class for a 2000 A rated pass-through sensor. In combination with the Power Analyzer PW8001, high frequency and low power factor power can be measured accurately.

Automatic Phase Correction function

To accurately measure high frequency and low power factor, it is important to correct phase errors. The PW8001 automatically acquires and corrects the phase of the current sensor with 0.001°resolution, bringing out the best performance of the current sensor without any effort.

Guaranteed accuracy when used in combination with a power analyzer

Hioki is able to guarantee the combined accuracy of the products when used together for greater customer peace of mind. Used in conjunction with a high-precision power meter such as Hioki’s Power Analyzer PW8001, the CT6877A can measure currents with a high degree of accuracy.

Example of the CT6877A being used with the Power Analyzer PW8001

From DC to 1 MHz, industry’s proven solution for high-accuracy power analysis.
The PW8001 features a phase shift function for current sensors to lock in accurate measurement of high-frequency power.
15 MS/s sampling at 18-bit resolution ensures true power analysis of PWM waveforms and results that are free of aliasing error.

Automatic detection capability for even greater convenience

Automatic current sensor detection by Power Analyzer PW8001

The current sensor is equipped with a memory (I2C-EEPROM).
When the current sensor is connected to the Power Analyzer PW8001, the phase correction data, rated current, sensor's model name, and serial number are automatically recognized by the instrument.

In the past, phase correction values had to be entered manually.
However, thanks to the automatic detection system of current sensor information, forgetting settings and typing errors are eliminated, allowing for more accurate power calculations.

Basic specifications

Accuracy guaranteed: 1 year
Rated current 2000 A AC/DC
Max. allowable input Within the derating range, (within the specified range up to ±3200 Apeak )
Frequency characteristics Amplitude: DC to 1 MHz, Phase: DC to 700 kHz
Basic accuracy (DC, 45 Hz ≤ f ≤ 66 Hz) Amplitude: ±0.04 % rdg. ±0.008 % f.s., Phase: ±0.08°
Output voltage rate 1 mV / A rated (This device outputs AC+DC voltage via the Sensor Unit)
Max. rated voltage to earth 1000 V AC/DC (50/60 Hz, CAT III )
Core diameter φ 80 mm (3.15 in)
Operating temperature, humidity -40°C to +85°C (-40°F to 185°F), 80% RH or less (with no condensation)
Power supply Power suppled via the Power Analyzer PW8001, PW6001, PW3390, Sensor Unit CT9555, CT9556, CT9557, or 3CH CURRENT UNIT U8977
Max. rated power 9.5 VA max. (at 2000 A/55 Hz, ±12 V power requirement)
Dimensions and mass 229 mm (9.02 in)W × 232 mm (9.13 in)H × 112 mm (4.41 in)D, CT6877A: 5 kg (176.4 oz), cable length 3 m (9.84 ft), CT6877A-1: 5.3 kg (186.9 oz), cable length 10 m (32.81 ft)
Included accessories Instruction Manual ×1, Mark bands ×6, Operating Precautions ×1

External power supply, Connection cord (5)

Compatible products PW3335, PW3336, PW3337, MR6000, MR8847A, MR8827, MR8740T, MR8740, MR8741, MR8870, MR8880, MR8875

Conversion/Extension cables (2)

The CT9902 connects up to 2 cables in series

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