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Switchgear Insulation & Monitoring

Insulators & Capacitive Sensors (12kV-40.5kV)

XBRELE’s Epoxy Post Insulators (ZJ Series) ensure robust mechanical support for busbars, while our Capacitive Sensors (CG5 Series) provide precise voltage indication signals. Manufactured via APG technology for superior dielectric strength and zero partial discharge.

CG5 Sensors ZJ Insulators APG Technology IEC 60660
Technical Overview

Advanced Epoxy Post Insulators & Sensors for MV Switchgear

XBRELE provides a comprehensive range of Indoor Epoxy Post Insulators (ZJ Series) and high-precision Capacitive Voltage Sensors (CG5 Series). These components are critical for medium voltage (12kV-40.5kV) distribution systems, ensuring safe busbar support and accurate voltage monitoring within compact switchgear environments.

Unlike traditional porcelain, our epoxy resin insulators are manufactured using APG (Automatic Pressure Gelation) technology. This guarantees high mechanical bending strength (up to 12kN) and superior dielectric properties with a Partial Discharge (PD) < 5pC. The integrated capacitive sensors in our CG5 series enable reliable connection to Voltage Presence Indicating Systems (VPIS), enhancing operator safety.

Designed for KYN28, XGN, and UniGear cabinets, our products strictly comply with IEC 60660 (Tests on indoor post insulators) and IEC 61243-5 (Voltage detecting systems). Whether you need standard support insulators or advanced sensor-integrated units, XBRELE delivers factory-direct quality.

For other essential components like wall bushings or contact boxes, explore our complete Switchgear Parts & Accessories Directory .

Insulators & Capacitive Sensors

High-precision CG5 sensors for VPIS and robust ZJ epoxy insulators for busbar support.

Capacitive Voltage Sensors (CG5) VPIS / Live Indication
12kV XBRELE 12kV Capacitive Voltage Sensors for KYN28 Switchgear
CG5-12kV Sensors
Key Models: Φ95×130, Φ100×140, Tower Capacitance: 15pF / 18pF
View Detailed Specs
17.5 / 24kV XBRELE 17.5kV and 24kV Epoxy Capacitive Sensors Export Type
CG5-17.5 / 24kV Series
Full Range: 17.5kV/90, 24kV/75, 85, 94, 110 Includes Export & Reinforced
View Detailed Specs
40.5kV XBRELE 40.5kV Heavy Duty Capacitive Sensors for KYN61
CG5-40.5kV Heavy Duty
Key Models: Φ100, Φ130, Φ155, Φ158 Height: 320mm – 480mm
View Detailed Specs
Combined XBRELE 3-Phase Combined Capacitive Sensors Block Type
Combined Sensors (Block)
Type: 3-Phase Conjoined Block For Compact Ring Main Units
View Detailed Specs
Epoxy Post Insulators (ZJ) Busbar Support
12 / 17.5kV XBRELE ZJ-12kV Epoxy Post Insulators for Busbar Support
ZJ-12kV / 17.5kV Series
Diameters: Φ65 (FN7), Φ70 (FN5), Φ80, Φ90 Includes 17.5kV Export Model
View Detailed Specs
24kV XBRELE ZJ-24kV High Strength Post Insulators 24kV
ZJ-24kV Series
Diameters: Φ75, Φ85, Φ110 Height: 190mm – 225mm
View Detailed Specs
40.5kV XBRELE ZJ-40.5kV Large Creepage Post Insulators
ZJ-40.5kV High Strength
Diameters: Φ130, Φ155, Φ158, A20 Bending: 8kN – 12kN
View Detailed Specs
Combined XBRELE Combined Post Insulators Block for Compact Switchgear
Combined Insulators
Features: 3-Phase Block, Chint Type Phase Dist: 101 / 232 / 320mm
View Detailed Specs
Specification Details ×
Technical Drawing
Select a model from the list
Material Epoxy Resin (APG)
Standard IEC 60660
Voltage —
ModelSizeThreadInfo
Engineered for Safety & Precision

Reliability of XBRELE Insulation Components

XBRELE utilizes advanced APG technology to manufacture high-strength Indoor Epoxy Post Insulators and precision sensing devices. Designed to withstand mechanical bending loads (up to 12kN) and ensure accurate monitoring in 12kV-40.5kV switchgear.

Molding Technology

APG Epoxy Resin Casting

The integrity of a dielectric body depends on its density. We utilize Automatic Pressure Gelation (APG) to eliminate internal voids.

  • Void-Free Structure: Ensures high insulation resistance for epoxy components in critical substations.
  • Mechanical Strength: ZJ series supports withstand high bending loads (4kN - 12kN) during short circuits.
  • Thermal Stability: Premium resin maintains performance under high temperatures. View all our switchgear parts.
Sensor Accuracy

Precision VPIS Monitoring

Safety relies on accurate indication. Our CG5 sensing units integrate high-stability ceramic capacitors.

  • Reliable Signal: Provides precise output for Voltage Presence Indicating Systems (VPIS) (DXN displays).
  • Low Partial Discharge: 100% testing ensures PD is less than 5pC, preventing internal breakdown.
  • Dual Function: Combines mechanical support with live line indication, saving space in compact cabinets.
Quality Assurance

X-Ray & Bending Tests

We employ X-Ray inspection and mechanical load testing on every batch of products to ensure structural integrity.

  • Non-Destructive Testing: X-Ray detects hidden micro-cracks inside the solid insulation.
  • Torque Strength: Brass inserts are tested to withstand high torque during busbar installation.
  • Standards: Verified against IEC 60660 requirements for indoor supports.
Quality Control

Manufacturing & Testing of Epoxy Insulators & Sensors

From raw resin mixing to final X-Ray inspection, XBRELE ensures every indoor post insulator (ZJ) and capacitive sensor (CG5) delivers zero-defect performance for MV switchgear.

APG Casting & Precision Assembly

Our production line for epoxy resin components utilizes advanced APG technology to eliminate internal voids, ensuring high mechanical strength for busbar support.

  • 01

    Mold Preparation

    Molds are pre-heated. Brass inserts for post insulators are positioned with high accuracy to ensure alignment.

  • 02

    APG Vacuum Casting

    Epoxy resin is injected under vacuum using APG technology, creating a dense, void-free dielectric body.

  • 03

    Curing & Demolding

    Controlled curing cycles prevent micro-cracking in the insulator body. Parts are inspected for surface finish.

  • 04

    X-Ray Flaw Detection

    Verifying the bonding between inserts and the epoxy matrix to ensure no hidden defects in the sensor body.

  • 05

    Final Testing

    Routine tests for withstand voltage, PD, and capacitance are conducted before the switchgear components are packed.

QA Standards

Routine & Type Tests

All insulators and sensors are tested per IEC 60660 / IEC 61243 to guarantee reliability in critical power networks.

Dielectric Performance

  • Power Frequency Withstand: 42kV (12kV units), 95kV (40.5kV).
  • Partial Discharge (PD): < 5pC at 1.1x rated voltage prevents epoxy insulation aging.
  • Impulse Voltage (BIL): Verified up to 75kV / 185kV for medium voltage systems.

Mechanical & Functional

  • Bending Load Test: Verifies strength (4kN-12kN) to withstand busbar stress.
  • Capacitance Check: Ensures voltage sensors provide accurate signals for VPIS.
  • Test procedures align with standards for solid electrical insulation.

Dimensional Verification

  • Precision check of mounting holes and insert threads.
  • Verification of conductor terminal alignment.
  • Surface creepage distance measurement for safety.
For test reports or other products like contact boxes, visit our Switchgear Parts pillar page.
Supply Chain & Support

Global Delivery for Insulation Components

XBRELE ensures rapid supply of indoor post insulators and capacitive sensors to switchgear manufacturers globally. We offer flexible customization for non-standard voltage ratings (e.g., 17.5kV) and secure export packaging.

Rapid Response

Stock Availability for ZJ & CG5

We maintain strategic inventory of standard models like ZJ-10kV/Φ65 and CG5-24kV/Sensor to support urgent retrofitting.

  • In-Stock Dispatch: Standard 12kV/24kV units ship within 3-5 days.
  • Bulk Production: 15-day lead time for large orders (>1000 pcs).
  • Spare Parts: Quick replacement for damaged busbar supports.
  • Sample Service: Prototype sensors available for VPIS testing.
Engineering Service

Custom Mold Design

XBRELE offers mold customization to fit unique cabinet geometries or special high-altitude insulation requirements.

  • Dimensional Adaptation: Custom height and diameter for tight spaces.
  • Insert Customization: M10/M12/M16 thread options for post insulators.
  • Voltage Ratings: Special designs for 17.5kV (Export) or 40.5kV.
  • Private Labeling: Laser marking for OEM switchgear brands.
Export Packaging

Secure Transport for Epoxy

Epoxy resin components require careful handling. We use multi-layer packaging to prevent chipping during sea or air freight.

  • Foam Protection: Individual wrapping for each sensor and insulator.
  • Reinforced Cartons: Heavy-duty boxes stacked on fumigated pallets.
  • Shock Absorption: Internal cushioning to withstand transit impact.
  • Documents: Test reports and compliance certs included.
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FAQ · Technical Support

Common Questions About Insulators & Sensors

Technical answers regarding post insulators, sensor capacitance, creepage distance, and compatibility with KYN28 switchgear.

What is the difference between ZJ and CG5 series?
The ZJ series consists of standard indoor post insulators designed purely for mechanical busbar support. The CG5 series are capacitive voltage sensors that combine mechanical support with an internal capacitor to provide voltage indication signals for VPIS (Voltage Presence Indicating Systems).
Can I use standard insulators for high altitude?
For altitudes above 1000m, standard insulators may risk flashover due to thinner air. We recommend our High Altitude series (e.g., ZJ-40.5kV/158), which features increased height and longer creepage distance to ensure safety in thin air environments.
What is the output of the capacitive sensors?
XBRELE capacitive sensors are designed to work with standard VPIS indicators (like DXN). The output voltage typically ranges from 10V to 100V depending on the system voltage (12kV/24kV), sufficient to drive neon or LED indicators without posing a danger to operators.
Do you offer 17.5kV insulators for export?
Yes. While 12kV is the standard in China, we manufacture specific 17.5kV post insulators (e.g., ZJ-17.5/90) and sensors to meet international IEC standards for 17.5kV switchgear systems, common in Southeast Asia and South America.
How to choose the right bending strength?
Bending strength (4kN, 8kN, 12kN) depends on the short-circuit current of your system. Higher short-circuit currents generate stronger electro-dynamic forces between busbars. For main busbars in 3150A switchgear, we recommend at least 8kN or 12kN post insulators.
Are these compatible with my existing switchgear?
Yes. Our insulators follow standard dimensions (e.g., mounting holes, height) for KYN28, XGN, and UniGear cabinets. You can check the specific dimensions in our product grid above or view our Contact Box Series for matching components.
Why use Epoxy Resin (APG) instead of porcelain?
Epoxy resin insulators (APG) are lighter, have higher tensile strength, and can be molded with tighter tolerances than porcelain. They are also less brittle and offer better resistance to thermal shock, making them the standard for modern indoor MV switchgear.
What is the lead time for sensors?
Standard models like CG5-12/100 and CG5-24/85 are often in stock. For custom capacitance values or special thread inserts, the lead time is typically 10-15 days. Please contact us for current stock levels.