Amrest Electricals Limited is a trusted manufacturer, exporter, and supplier of high-performance Current Transformers (CTs) up to 33kV. With a focus on quality, innovation, and customer-centric solutions, we provide advanced transformer technologies for accurate metering and reliable protection in electrical systems.

Our products are engineered to perform efficiently in diverse industrial and utility environments, meeting both national and international standards.

1. Indoor Resin Cast Current Transformers

Designed for indoor installations, these transformers are manufactured using high-grade epoxy resin, ensuring excellent insulation and safety.

Key Features:

  • Compact and maintenance-free design
  • High mechanical and thermal strength
  • Superior insulation with epoxy resin casting
  • Flame-retardant and moisture-resistant
  • High accuracy for metering and protection

Applications:

  • Switchgear panels
  • Control rooms
  • Industrial power distribution

2. Outdoor Oil-Cooled Current Transformers

Built for outdoor environments, these CTs use high-quality insulating oil for cooling and insulation, ensuring long-lasting and stable performance.

Key Features:

  1. Excellent heat dissipation
  2. Suitable for harsh weather conditions
  3. Robust and corrosion-resistant construction
  4. Long service life
  5. High reliability in continuous operation

Applications:

  • Substations
  • Transmission & distribution networks
  • Utility power systems

3. Outdoor Resin Cast Current Transformers

Maintenance-free and environmentally friendly, these CTs are ideal for outdoor installations without the need for oil.

Key Features:

  • Oil-free, eco-friendly design
  • UV-resistant and weatherproof
  • High dielectric strength
  • Compact and lightweight
  • Minimal maintenance requirements

Applications:

  • Outdoor switchyards
  • Renewable energy installations
  • Industrial outdoor setups
current transformer - amrest electricals

Key IEC Standards for Current Transformers

The primary standard for instrument transformers was transitioned from IEC 60044 to the IEC 61869 series. For your specific product line, these are the critical benchmarks:

  • IEC 61869-1: General requirements for all instrument transformers.
  • IEC 61869-2: Specific requirements for Current Transformers (replaces the old IEC 60044-1).
  • IEC 60076: While mainly for power transformers, parts of this standard apply to the oil and insulation used in your Outdoor Oil Cooled units.

Critical Parameters Required by IEC

When you are manufacturing for a customer “as per requirement,” the IEC standard dictates how you must define and test the following:

1. Accuracy Classes
  • Metering CTs: Must follow classes like 0.2, 0.2s, 0.5, or 0.5s. The “s” denotes higher accuracy at very low current levels (essential for billing).
  • Protection CTs: Must follow classes like 5P10 or 10P20.
    • 5P means 5% error.
    • 10 means it can handle 10 times the rated current without saturating (Accuracy Limit Factor).
2. Insulation Levels (Up to 33kV)

For your 33kV Resin Cast and Oil Cooled units, the IEC standard defines the Basic Insulation Level (BIL):

  • Rated Power Frequency Withstand Voltage: Typically 70kV for a 33kV system.
  • Rated Lightning Impulse Withstand Voltage: Typically 170kVp (peak).
3. Temperature Rise

IEC standards strictly limit how hot the resin or oil can get during operation to ensure the transformer lasts 20-25 years without the insulation breaking down.

Testing Requirements (IEC 61869-2)

To be a leading exporter, your units must undergo these “Routine Tests” before leaving the factory:

  1. Verification of terminal markings (P1, P2, S1, S2).
  2. Power-frequency voltage withstand test on primary and secondary windings.
  3. Partial Discharge (PD) measurement: Especially critical for your Resin Cast units to ensure there are no air bubbles inside the epoxy.
  4. Inter-turn overvoltage test.
  5. Accuracy test: Comparing the ratio and phase displacement against the standard.

We are Manufacturer, Exporter and Supplier of  Current Transformer  for India, United Arab Emirates , Dubai , Sharjah , Saudi Arabia , Bahrain , Iraq , Kuwait , Oman , Qatar, Afghanistan, South Africa , Zambia , Tanzania , Ghana , Nepal , Bhutan , Bangladesh, Indonesia, Kenya , Malaysia, Turkey, Zimbabwe and other countries.