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- Description
- Specifications
- Applications
- Advantages
- FAQ
- Recommended Products
Description
The DRM-20M DC Winding Resistance Meter is a professional high-current automatic DC resistance tester specially designed for transformer winding DC resistance measurement. It adopts high-power constant-current source technology, ultra-low resistance high-precision sampling, and intelligent fast steady-state algorithm, which greatly shortens the charging stabilization time of large inductive transformer windings.
It accurately measures DC resistance of transformer windings, CT/PT coils, reactor coils and other inductive loads, automatically converts resistance value to 20℃/75℃ standard temperature, judges winding asymmetry fault, and completes automatic demagnetization after testing. Fully compliant with IEC 60076-2, IEEE C57.12.90, GB/T 1094, it is widely used in transformer factories, power substations, maintenance and third-party testing institutions.
Specifications
| Parameter | Specification |
| Model | DRM-20M |
| Maximum Test Current | 20A DC |
| Resistance Measurement Range | 1μΩ ~ 20kΩ |
| Measurement Accuracy | ±0.02% ±1μΩ |
| Minimum Resolution | 0.1μΩ |
| Temperature Compensation | Auto convert to 20℃ / 75℃ standard resistance |
| Core Functions | Fast steady-state measurement, automatic demagnetization, three-phase unbalance calculation |
| Test Object | Transformer winding, CT/PT, reactor, HV motor inductive coil |
| Display | 7-inch color touch LCD |
| Power Supply | AC 220V±10%, 50/60Hz |
| Operating Temperature | -10℃ ~ +50℃ |
| Humidity | ≤90% RH non-condensing |
| Protection Grade | IP40 |
| Net Weight | ~11kg |
| Compliance Standards | IEC 60076-2, IEEE C57.12.90, GB/T 1094, CE |
Applications
· DC resistance test of oil-immersed & dry-type power/distribution transformer windings
· CT, PT current/voltage transformer coil DC resistance measurement
· Reactor, grounding transformer, zig-zag transformer winding resistance test
· HV motor, generator stator winding DC resistance inspection
· Transformer OLTC tap position resistance consistency comparison test
· Substation preventive maintenance, factory type test, handover acceptance test
Industries
Power grid utilities, transformer manufacturers, industrial power maintenance, rail transit, new energy power stations, third-party inspection & certification labs
Advantages
IEC Global Standard Compliance
Strictly follow IEC 60076-2 transformer temperature rise & resistance test standards, IEEE C57.12.90, test data internationally recognized for export and grid access.
20A High Current Fast Inductive Testing
High-power 20A constant current source, much faster than ordinary low-current testers, shortens waiting time for large inductive transformer windings, greatly improves field test efficiency.
Automatic Demagnetization To Ensure Test Accuracy
Built-in full-process demagnetization, completely solve residual magnetism interference, ensure consistent and accurate TTR, no-load loss follow-up test data.
Ultra-Low Resistance High Precision
1μΩ minimum resolution, ±0.02% high precision, accurately detect tiny winding turn-to-turn short circuit, poor contact, tap changer abnormal faults.
Fully Automatic No Professional Operation
One-click test, automatic temperature compensation, unbalance calculation, report output, reduce technical threshold for on-site operators.
Safe Inductive Load Discharge Protection
Built-in powerful energy discharge circuit, completely release inductive high voltage after test, protect operators and equipment from electric shock hazard.
FAQ
Q: Why does transformer winding test need automatic demagnetization?
A: DC test leaves residual magnetism in transformer core, which will seriously distort turns ratio, no-load current and loss test results. DRM-20M automatically demagnetizes after test to ensure all subsequent tests accurate.
Q: What is the maximum test current of DRM-20M?
A: Max output 20A DC constant current, suitable for large-capacity high-voltage power transformer winding resistance testing.
Q: How low resistance can it measure?
A: Minimum measurable 1μΩ, ultra-high resolution can find tiny winding defects and poor tap contact faults.
Q: Can it automatically compensate temperature?
A: Yes, input ambient temperature, instrument automatically converts resistance to standard 20℃/75℃ value, fully meets IEC transformer test requirements.
Q: Is it suitable for on-site outdoor use?
A: Yes, wide temperature adaptability, rugged portable structure, stable anti-interference performance, perfect for substation field maintenance.
Q: Warranty & service?
A: 1-year whole machine warranty, lifetime technical support, on-site calibration and training.
