LZZB9 Series 35kV Fully Enclosed Post-Type Current Transformer | DSJ Electrical

1. Product Overview
The LZZB9 series is a fully enclosed cast resin post-type current transformer designed for 35kV medium-voltage power distribution networks. Manufactured with advanced epoxy casting insulation technology, this range includes three structural variants: LZZB9-35C, LZZB9-35D, and LZZB9-35DG, tailored to diverse substation, industrial, and offshore onshore power project demands.
As a core measuring and protective component in high-voltage switchgear, the LZZB9 CT converts high primary load current into standardized low secondary current (5A / 1A). It delivers accurate signal transmission for energy metering, power monitoring, and relay fault protection, widely adopted in power plants, municipal grids, mining facilities, and industrial electrical systems.

2. Model Code Definition
Each letter and digit in the LZZB9 model carries a clear technical meaning for quick engineering identification:
L: Current Transformer
Z: Post Type Mounting Structure
Z: Cast Resin Insulation
B: Equipped with Protective Winding
9: Serial Design Number
35: Rated Voltage (35kV)
C / D / DG: Structural Differentiation Code

3. Core Technical Specifications
Basic Standard Parameters
Rated Insulation Level: 40.5/95/185kV
Rated Frequency: 50Hz
Rated Secondary Current: 5A or 1A (customer optional)
Load Power Factor: cosφ=0.8 (lagging)
Apparatus Security Factor (FS): ≤10
Compliance Standard: GB1208-2006 Current Transformer National Standard
Environmental Pollution Adaptability
LZZB9-35C: Class II pollution tolerance, suitable for clean urban and indoor substation environments
LZZB9-35D / LZZB9-35DG: Class III pollution resistance, ideal for coastal, mining, industrial and heavy dust outdoor power sites
Short-Time Thermal & Dynamic Stability
The entire LZZB9 lineup features robust short-circuit withstand capacity:
Rated short-time thermal current: 31.5kA / 40kA / 160kA options
Rated dynamic current: 80kA / 100kA / 375kA peak values
The epoxy cast structure effectively resists thermal shock and electromagnetic impact during short-circuit faults, extending service life for long-term continuous operation.
Wide Primary Current Range
Covering all mainstream medium-voltage load requirements:
LZZB9-35C: 30A ~ 2000A rated primary current
LZZB9-35D / DG: 30A ~ 3000A rated primary current
Multi-Class Accuracy Combinations
Customizable dual-winding accuracy classes for combined metering + protection functions:
0.2S, 0.2, 0.5, 10P10, 10P15, 10P20
Matching rated output capacity from 10VA up to 50VA to fit different distance wiring and instrument loads.

4. Key Product Advantages
Full Epoxy Cast Insulation
Seamless epoxy resin encapsulation eliminates air gaps inside the unit, delivering excellent anti-aging, moisture-proof, dust-proof and anti-corrosion performance. No maintenance required for long-term field operation.
Dual Pollution Grade Options
Two pollution resistance grades support flexible site matching: Class II for urban standard substations, Class III for harsh industrial, coastal and mining environments, lowering equipment failure risks under severe weather conditions.

Integrated Measuring & Protection Windings
Dual secondary winding design simultaneously supports precise energy measurement and reliable fault relay protection, simplifying switchgear layout and reducing overall cabinet construction costs.
High Short-Circuit Withstand Capacity
Optimized electromagnetic coil structure enhances thermal and dynamic stability during power grid short-circuit accidents, preventing coil deformation and insulation breakdown.
Standardized & Customizable Design
All models fully comply with GB1208-2006 national standards. DSJ Electrical accepts customizations for primary current ratio, secondary output capacity, accuracy class, and mounting dimensions to match client-specific switchgear projects.

5. Typical Application Scenarios
35kV indoor metal-clad switchgear rooms
Urban and county power grid substations
Heavy industry plants, chemical factories, mining power supply systems
Onshore & offshore auxiliary power distribution equipment
Government infrastructure and state-owned enterprise power projects

6. About DSJ Electrical
DSJ Electrical cooperates with Dalian No.2 Instrument Transformer Group Co., Ltd., the manufacturer of LZZB9 series CTs with 45 years of professional transformer production experience. We provide full-set 35kV current transformers with complete factory test reports, COC certificates, and third-party inspection documents.
We support factory inspection before shipment and on-site acceptance after delivery. Our engineering team offers free technical drawing consultation and parameter matching for your medium-voltage projects, covering global markets including Australia, Africa, Southeast Asia and the Middle East.
Call to Action
If you require technical datasheets, quotation, or customized design of LZZB9-35C/D/DG 35kV current transformers, contact our sales team for fast professional support.
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