LMK-0.66 LV Current Transformer | ZHNYU

The ZHNYU LMK-0.66 series represents a dependable range of low-voltage current transformers engineered for 50Hz AC electrical distribution infrastructure. Operating at a rated voltage of 0.66kV, this low voltage current transformer steps down high primary currents into safe, standardized secondary values of 5A or 1 E for digital meters, ammeters, and protective relays. 

ZHNYU manufactures every unit using high-grade flame-retardant molded plastic housing that completely seals the internal core and secondary windings. This protective casing eliminates exposed electrical terminations, removing the need for extra secondary insulation inside crowded switchboards. Whether deployed in industrial main switchboards or commercial sub-distribution boards, the ZHNYU molded case current transformer adapts easily to different installation footprints while ensuring long-term electrical reliability. Every single current transformer undergoes rigorous testing to guarantee stable performance under fluctuating thermal and electrical operational cycles.

Key Product Features

• Flame-Retardant Molded Housing: ZHNYU encloses the internal components inside a durable molded case that offers high mechanical strength and reliable fire resistance.

• Revenue-Grade Accuracy Options: Available in Class 1, 0.5, 0.5S, 0.2, and 0.2S classes, where the 0.2S rating ensures precise metering performance even down to light load conditions.

• Busbar-Ready Window Design: The spacious central window accommodates copper busbars directly, allowing fast retrofit installation into live panels without breaking primary circuit connections.

• Slim Profile Across All Sizes: Spanning seven distinct frame sizes, all units maintain a consistent slim depth of 34mm to 40mm, maximizing interior clearance in compact low voltage current transformer panels.

• Standard Compliance: Fully aligned with GB 1208 specifications and manufactured under ISO9001 and CE quality frameworks.

Technical Advantages

Deploying a ZHNYU low voltage current transformer inside electrical distribution networks brings distinct engineering benefits. In many industrial environments, fluctuating loads make standard accuracy classes insufficient during low-load intervals. The inclusion of Class 0.2S and 0.5S options in the ZHNYU product lineup solves this challenge by maintaining tight error limits from 1% up to 120% of rated primary current, making this window type current transformer ideal for commercial energy billing.

Furthermore, panel builders frequently struggle with tight physical space inside low-voltage switchgear. ZHNYU addresses this constraint by optimizing the outer dimensions across all seven frame sizes—ranging from 20 I to 80-I—while maintaining a slim depth profile. This thoughtful mechanical layout prevents overcrowding, simplifies cable routing, and allows smooth integration alongside circuit breakers and contactors within a standard molded case current transformer configuration.

Technical Specifications Table

Applications

• Low-Voltage Main Distribution Panels: Installed directly on busbars in main switchboards using a window type current transformer structure to feed current signals to multi-function power meters without cutting primary lines.

• Commercial and Residential Sub-Metering: Positioned in floor-level distribution boards to monitor energy consumption for tenant billing and energy audits, supported by Class 0.2S accuracy.

• Motor Control Centers (MCCs): Mounted inside standard MCC enclosures alongside contactors to supply overload relays and PLCs with accurate current data for real-time motor protection.

• Renewable Energy Systems: Integrated on the AC output side of solar inverters and energy storage power conversion systems using a reliable low voltage current transformer to measure generation output.

Commercial Value & Engineering Support

Selecting the correct current transformer is vital for accurate energy accounting and reliable system protection. Inaccurate measurement leads to billing disputes, while poor thermal endurance can cause hardware failure during overcurrent events. ZHNYU bridges this gap by combining precise manufacturing standards with practical engineering support.

ZHNYU provides free technical guidance for ratio and accuracy selection based on client single-line diagrams, alongside 3D STEP models and dimension drawings for efficient panel design. Backed by a 24-month manufacturing warranty and flexible support for custom ratios, ZHNYU remains a trusted partner for electrical contractors and panel builders seeking a dependable molded case current transformer.

Frequently Asked Questions (FAQ)

Q1: What is the main advantage of choosing Class 0.2S over standard accuracy classes?

A: Class 0.2S maintains high measurement accuracy even when the primary current drops down to 1% of its rated value. This makes a ZHNYU low voltage current transformer with 0.2S accuracy ideal for commercial billing applications where power consumption fluctuates significantly throughout the day.

Q2: Can the ZHNYU LMK-0.66 series be installed on existing live busbars?

A: Yes. The window type current transformer design features a central opening that allows copper busbars to pass straight through, enabling retrofit installations during scheduled maintenance windows without breaking the main circuit.

Q3: Does ZHNYU support custom current ratios or secondary outputs?

A: Yes. While standard primary currents range from 5A to 2000A with 5A or 1A secondaries, ZHNYU accommodates custom ratios and dual-secondary winding configurations for volume orders upon request.