Maximize Efficiency & Power Factor
A low voltage current transformer is a passive device used to reduce high primary currents to a standardized, lower secondary current for measurement or protection. It is designed for systems up to 1 kV AC, which covers most industrial distribution panels, commercial meter cabinets, and motor control centers. Unlike power transformers, a Low Voltage Current Transformer prioritizes accuracy and phase fidelity over power throughput. Typical secondary outputs are 5 A or 1 A, allowing standard meters and relays to operate safely without direct contact with high current lines. You often see them installed on busbars, cables, or windings inside low voltage switchgear.
| Function | Description | Typical Data / Range |
|---|---|---|
| Current Measurement | Reduces primary line current to a safe secondary value | Primary: 5 A up to 5000 A |
| Energy Metering | Feeds accurate current signals to kWh meters | Accuracy Class: 0.2, 0.5, 1.0 |
| Protection Relaying | Drives overcurrent or earth fault relays | Burden: 2.5 VA – 30 VA |
| Electrical Isolation | Separates measuring instruments from high current circuits | Insulation level: 0.72/3 kV |
| Power Quality Monitoring | Sends waveform data for harmonic analysis | Frequency: 50 Hz or 60 Hz |
This table helps engineers and procurement teams quickly match the low voltage current transformer to their system requirements.
| Parameter | Typical Value / Range | Notes |
|---|---|---|
| Rated Primary Current | 100 A to 3000 A | Lower values available on request |
| Rated Secondary Current | 5 A or 1 A | 1 A reduces line drop over long cables |
| Accuracy Class (Metering) | 0.2, 0.5, 1.0 | 0.2S / 0.5S for wide measuring range |
| Accuracy Class (Protection) | 5P10, 10P10, 5P20 | ALF (Accuracy Limit Factor) |
| Rated Burden (VA) | 1.5, 2.5, 5, 10, 15, 30 | Depends on core cross‑section |
| Short‑time Thermal Current | 20 × rated primary for 1 second | Withstands fault current |
| Rated Insulation Voltage | 0.72/3 kV (full wave) | 50/60 Hz dielectric test |
| Operating Frequency | 50 Hz / 60 Hz | Same unit works for both |
| Ambient Temperature Range | –25°C to +55°C | Indoor or outdoor enclosure options |
| Construction Type | Wound primary / Bar primary / Split‑core | Split‑core suited for retrofits |
Where Our Low Voltage Current Transformer Delivers Proven Results
A low voltage current transformer is not a one‑size‑fits‑all component either. Below are field scenarios where our low voltage current transformer improves measurement consistency, supports selective protection coordination, and delivers reliable current data for energy accounting — without interrupting the main conductor during installation.
Our low voltage current transformer maintains Class 0.2S accuracy from 1% to 120% of the rated primary current. Many standard units only perform well near full load, but ZHIMING devices give you reliable readings even when the line runs lightly loaded — for example, overnight or during seasonal low production.
The split‑core version of our low voltage current transformer opens around existing cables or busbars without disconnecting the primary conductor. You do not need to shut down a whole production line or pull a switchgear apart just to add a metering point.
Not every installation has the meter sitting right next to the transformer. With a ZHIMING low voltage current transformer, you can drive long cable runs to a central panel, or connect multiple instruments in series, without exceeding the rated burden.
Whether your plant operates on a 50 Hz grid in Europe or a 60 Hz grid in North America, the same ZHIMING low voltage current transformer covers both.
Some low voltage current transformers saturate too early when an electric motor starts or when a transformer energizes, causing the protection relay to see a distorted current waveform and trip unnecessarily.
If your project needs a non‑standard primary current rating, a different window size, or a special secondary output, ZHIMING does not start from zero. We keep premade cores, enclosures, and terminals in stock, so a modification typically takes days instead of months.
A leading power capacitor manufacturer with over 25 years of experience is here to answer all your inquiries—covering any product-related issues, business questions, or service-related concerns.
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Yes, if your safety procedures allow it. ZHIMING split‑core models include a non‑magnetic latch and self‑closing mechanism. However, you must follow local lockout/tagout rules first.
Dangerous high voltage will appear at the secondary terminals. It can cause arcing, damage insulation, or injure personnel. Always short the secondary terminals before removing a connected meter.
Use 5 A when the distance to the meter is short (≤10 meters) and your meter accepts 5 A directly. Choose 1 A when the cable run exceeds 20 meters, or when you want to minimize burden losses.
Generally no. Metering cores saturate earlier to protect the meter; protection cores need to remain linear under fault currents. If you need both functions from one device, select a dual‑winding low voltage current transformer.
Yes. Above 55°C core losses change and ratio error increases. ZHIMING low voltage current transformers include temperature coefficients per IEC 61869‑2. For outdoor hot climates, choose a down‑rated primary current or a larger window size.
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