LMZ metering current transformer, designed specifically for the Thai market, meet the high accuracy and high reliability requirements of MEA and PEA projects.

In Thailand’s power infrastructure construction, precision and reliability are core requirements. For transformer companies and electrical contractors supplying projects to the Metropolitan Electric Power Authority (MEA) and Provincial Electric Power Authority (PEA), every component must meet stringent technical standards.

The LMZ series metering current transformer are designed to meet these stringent requirements. Whether you are an engineer responsible for selecting protection systems or a procurement manager ensuring equipment complies with grid specifications, a thorough understanding of the technical details of current transformers is crucial. This article will analyze several key technical issues and explain why the LMZ series is the ideal choice for Thailand’s power sector.

What accuracy level is required for a billing current transformer?

In metering applications involving electricity billing, accuracy is paramount. Thailand’s MEA and PEA typically require current transformers used for metering to achieve an accuracy of 0.5 class or even 0.2 class to ensure fair and accurate billing.

LMZ current transformers offer 0.5-class accuracy, making them ideal for billing applications. With a primary current range of 100–400A and a secondary output of 5A, they provide the high-precision measurements required for industrial and commercial metering. This not only ensures accurate electricity data but also helps users reduce electricity bill losses while meeting the compliance requirements of the Electricity Generating Authority of Thailand (EPT).

What is the difference between a protection current transformer and a metering current transformer?

Correctly distinguishing between current transformers for protection and current transformers for metering is fundamental to system design.

Current transformers for metering (such as the LMZ series) prioritize measurement accuracy under normal operating conditions. They maintain linearity within 120%–150% of the rated current and are suitable for 0.5 or 1.0 accuracy class, primarily used for billing and monitoring.

The current transformer for protection is required to remain unsaturated under high fault current to ensure reliable operation of the relay protection device, with priority given to stability under short-circuit conditions.

The LMZ current transformer is designed specifically for metering applications, perfectly meeting the core requirements of accurate energy accounting in MEA and PEA projects.

Can a current transformer be installed on both the live wire and the neutral wire at the same time?

Yes, but caution is required depending on the specific scenario. In a single-phase system, the current transformer is usually installed on the live wire. However, in a three-phase system or residual current detection scenario, it may be installed on the neutral wire.

In metering applications in Thailand, current transformers are typically installed on the live wires of each phase. The LMZ current transformer boasts excellent insulation performance, with a withstand voltage of up to 4kV/min between the primary and secondary windings and an insulation resistance as high as 1000MΩ (500V DC). Whether installed on the live or neutral wire, it ensures safe and reliable operation as long as local wiring specifications are followed.

Product features specifically designed for Thai working conditions

LMZ current transformers have been optimized for the environmental and operating conditions in Thailand.

Wide operating temperature range: –40℃ to 85℃, suitable for indoor substations and outdoor installation scenarios.

Altitude adaptability: It can operate stably in areas with an altitude not exceeding 1000 meters.

Standards compliance: Fully compliant with IEC 61869-2:2012 standard, meeting the technical requirements of MEA and PEA projects.

Compact structure: Small size, easy to integrate into existing switch cabinets and metering panels.

Why choose the LMZ series for MEA/PEA projects?

For engineers and procurement personnel involved in the construction of Thailand’s power grid, selecting components that meet the standards of local power companies is crucial. The LMZ series helps simplify compliance efforts, with key advantages including:

0.5 accuracy class – suitable for billing and metering

IEC 61869-2 Certification – Ensuring International Quality and Safety

Rigorous withstand voltage and insulation testing – able to withstand high voltage and extreme temperatures

Wide frequency compatibility – supports 50Hz and 60Hz systems, adapted to the characteristics of the Thai power grid.

Whether you are designing a new substation, upgrading a metering system, or selecting components for an MEA or PEA project, LMZ current transformers meet the high standards of the Thai power industry in terms of accuracy, safety, and compliance.

It integrates high-precision metrology performance with a robust and reliable structural design, precisely addressing the core concerns of engineers and purchasing managers regarding system reliability, standards compliance, and long-term value.

Compay：HEYI Electrical Co., Ltd.
Brand: HEYI/ASCT
Contact: Bethy
E-mail: heyi@heyiele.com             
Tel: 86-13968747975

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