Current Transformer Field Tester

Refine On (Hebei) Electric Power Technology Co., Ltd. is one of the leading manufacturers and suppliers of current transformer field tester in China. If you're going to wholesale durable current transformer field tester, welcome to get quotation from our factory. All customized products are with high quality and competitive price.

The NRH70C Current Transformer Field Tester integrates a built‑in 0.05‑class standard CT and VT, supports CT ratios from 5A/5A up to 31500A/5A, and delivers measurement accuracy equal to 1/3 of the tested CT's error limit. Its recursive measurement method and near‑power‑frequency power supply reduce field interference, while the 8‑inch touchscreen, data storage for 5,000 records, and multiple interfaces (USB, Bluetooth, RS232, RJ45) make it a comprehensive tool for field metering verification.

1. Current Transformer Error Measurement Section

① Overall accuracy: 1/3 of the error limit of the tested current transformer.

② Test range: 5A/5A to 31500A/5A or 5A/1A to 6300A/1A

Rated primary current range of a 5A secondary current transformer:

Rated primary current range of current transformers with 1A secondary current:

Note: A current transformer with a secondary current of 5A can achieve a ratio of 31500A/5A through the equal current-turn measurement method.

Equivalent-turn test method examples:

③ The working range of the tested current transformer is 1%～200%.

④ Secondary load: 2.5VA to 300VA, with a power factor (COSφ) ranging from 0.1 to 1.0.

⑤ The accuracy range of the tested current transformer is: 1.0, 0.5, 0.5S, 0.2, and 0.2S.

⑥ Resistance and admittance measurement error ≤5.0%.

Measurement range: R: 0.00Ω to 20.0Ω; Y: 0.000mS～100.0mS.

2. Voltage Transformer Calibration Instrument Section

Voltage ratio test range: 1KV-500KV.

3. Instrument power consumption: 20VA.

4. Instrument accuracy class: 0.05S class.

5. Maximum dimensions (cm): L460 × W375 × H183.

6. Weight (kg): 10.0.

• Built‑in 0.05‑class reference standards – No external standard CT or VT required.
• Wide CT ratio coverage – From 5A/5A to 31500A/5A (via equal‑ampere‑turn method).
• High‑accuracy error measurement – Overall accuracy equals 1/3 of the tested CT's error limit.
• Automatic fault diagnosis – Detects wiring errors, wrong ratio, or polarity issues with on‑screen alerts.
• Simultaneous VT ratio & polarity test – Unique feature among domestic instruments.
• Large data capacity – Stores 5,000 test records with USB/Bluetooth/RJ45 export.
• Long battery operation – >12 hours on full charge; built‑in lithium battery.
• Rugged construction – Engineering plastic housing, shockproof and pressure‑resistant.

• On site verification of high voltage energy metering devices in power plants and substations.
• Field testing of current transformers (CT) and voltage transformers (VT) for ratio, polarity, error, and DC resistance.
• Inspection of secondary loads and winding internal resistance.