Description

Technical Parameters

Product Overview & Application Scenarios

Product Overview

An HM-HL Precise Standard Current Transformeris a highly accurate device used exclusively in laboratories and calibration centers to benchmark and verify the accuracy of other, lower-grade current transformers (CTs) and electrical measuring instruments.

Application Scenarios

1.Calibration of High-Ratio Current Transformers (CTs)：Testing CTs with very high ratios (e.g., 2000/5A, 3000/1A) used in electrical substations, steel mills, and large manufacturing plants.
2. Type Testing and Certification of Energy Meters：Manufacturers and calibration labs use it to certify the accuracy of high-current energy meters used by large industrial customers.
3.Verification of Primary Injection Testers：Checking the accuracy of the high-current test sets used by utility crews for maintenance.

Key Features & Advantages

Product Features

1.The instrument is composed of primary winding and secondary winding.

2.Self-calibration of current ratio of 5/5 or 1/1

3.With casters for easy handling

4.Test in accordance with the nameplate indicating standard current ratio.

Advantages

1. Ultra-High Accuracy at High Currents:It provides laboratory-grade precision (e.g., 0.01% accuracy) even when generating thousands of amperes.
2. Extended Range Without Accuracy Loss:The current booster amplifies current while the HM-HL transformer maintains measurement integrity.
3.Traceable Compliance:It offers metrological traceability to national/international standards.
4. Single-Device Efficiency:Replaces complex setups of multiple transformers and amplifiers.
5.Stability Under Load:Maintaining accuracy despite fluctuations in current or temperature.
6.Cost-Effective for High-Current Applications:Eliminating the need to purchase expensive, high-capacity reference standards.
7.Enhanced Diagnostic Precision: It detects minute deviations in CT performance under realistic high-current conditions.

Operating Conditions

1.Environmental Conditions

Temperature:－5°C to 40°C (stable laboratory environment)

Humidity:<80%

Altitude:Below 1000 meters for rated accuracy

Location:Clean, vibration-free, and electromagnetically shielded space

2. Power Supply Requirements

Voltage:Stable AC supply (220V ±5%, 50/60Hz)

Grounding:Low-resistance earth ground (<0.5 ohm)

Capacity:Sufficient power for booster output (typically 5-10kVA)

Additional Information

Alternative Names:

Ratio Standard Test Set

Primary Current Injection Test Set

Current Amplifier System with Reference Standard:

Current Comparator System (with Amplifier)

Precision Current Injection System

Traceable Current Calibrator

Reference Standard Current Source

High-Current Calibration System

CT Calibration System

Current Transformer Test Set (with Booster)

Precision Current Calibration Set

Maintenance & FAQs

Q: What is this system, and what is its main purpose?

A: It is a high-precision calibration system used to generate and measure very high currents (thousands of amperes) with extreme accuracy. Its primary purpose is to test, calibrate, and certify large current transformers (CTs) and energy meters used in power systems and heavy industry.

Q: Why is a "current booster" needed with the standard transformer?

A: The HM-HL transformer alone cannot produce the high currents required to test large CTs. The booster acts as a "power amplifier," magnifying a lower input current to the high levels needed while the HM-HL transformer ensures precise measurement.

Q: What industries use this system?

A:It is critical for:

Power utilities(calibrating substation CTs for billing and protection).

Heavy industries(steel plants, smelters, data centers) to verify accuracy of high-current meters.

Calibration laboratoriesand meter manufacturers for certification.

Q: How accurate is this system?

A: The HM-HL transformer provides laboratory-grade accuracy, typically 0.01% to 0.05%, even at high currents amplified by the booster. This makes it 10–100 times more precise than typical industrial CTs.

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Technical Specifications

1. Temperature: -5- +40℃

2. Humidity: <80%

3. Capacity: 5VA, 1VA COSφ=1

4. Primary current: 5-2000A

5. Secondary current: 5A, 1A

6. Accuracy level: 0.05S level

7. Rated voltage: 500V

8. Frequency: 50Hz

9. Long-term work under rated current is allowed, and the core is above 120A.

Capacity	5VA, COSØ=1	Frequency	50Hz
Primary Current	5~10000A	Secondary Current	1A, 5A
Accuracy Level	0.01(S),0.02(S)/0.05(S)	Rated Voltage	500V
Workplace should not have non-work related strong external electromagnetic field
low long-term working under rated current