Ceramic Insulator Sensor

Model:
HMJ1010-WTX

Product Overview

The Ceramic Insulator Sensor is designed for continuous real-time acquisition of ABC three-phase partial discharge (PD) signals and overvoltage signals from low-voltage overhead distribution lines. Installed at the high-voltage incoming side of transformers, it couples and senses internal transformer partial discharge signals. The sensor transmits collected data via RS485 to an access node, which processes and forwards the data wirelessly or through wired connections to the server. Operators can monitor transformer operating status through a backend system. When suspected PD signals are detected, alarm information and corresponding spectral analysis help assess the severity and trends of partial discharge, enabling timely maintenance decisions.

 

Key Features

• Accurate Measurement: Precisely measures line voltage, providing reliable data to detect voltage abnormalities and support power system stability.
• Real-Time Monitoring: Continuously monitors voltage fluctuations and overvoltage events with fast response to ensure stable system operation.
• High Insulation Strength: Ceramic material offers excellent insulation, safely isolating high voltage to guarantee sensor operation in harsh high-voltage environments.
• Strong Anti-Interference: Uses ceramic insulator coupling signals to effectively resist external electromagnetic interference, ensuring stable signal transmission.
• Easy Installation: Compact and lightweight design facilitates installation and layout in low-voltage distribution areas.

 

Technical Specifications

Parameter	Specification
Applicable Ceramic Capacitor Range	50–1000 pF
Frequency Detection Range	500 kHz – 30 MHz
Amplitude Measurement Range	0–67 dB
Amplitude Linearity Error	≤ ±15% (dynamic range 40 dB)
Measurement Impedance	10 kΩ
Discharge Quantity Range	10 pC – 10 nC
Partial Discharge Sensitivity	≥10 pC
Operating Temperature	-40°C to +85°C
Operating Humidity	5% to 95% RH

Frequently Asked Questions about ceramic insulator sensor

What is the ceramic insulator sensor (HMJ1010-WTX) used for?

The ceramic insulator sensor — model HMJ1010-WTX is designed for continuous online partial discharge monitoring of HV switchgear and cables. It is deployed in HV switchgear, cable terminations, GIS and transformer bushings, where it gives maintenance teams continuous or periodic visibility of insulation condition so that defects can be identified before they develop into unplanned outages.

What is the applicable ceramic capacitor range of the HMJ1010-WTX?

According to the published specification, the applicable ceramic capacitor range is 50–1000 pF. This figure is measured under the reference conditions stated in the product datasheet; for project-specific acceptance criteria please refer to the type test report supplied with the quotation.

Which detection principle does this sensor use, and how do I choose?

Different partial discharge defects are best seen with different coupling methods. UHF sensors pick up electromagnetic waves emitted by discharge inside metal-enclosed equipment and give good immunity to corona from outside; HFCT sensors couple to the pulse current flowing on the earthing or cable screen and suit cable and transformer applications; contact ultrasonic and TEV sensors are used for surface and internal discharge in switchgear. The HMJ1010-WTX listed here applies the principle best matched to its intended installation, and multi-function versions combine several principles in one housing where the defect type cannot be predicted in advance.

Is installation possible without an outage?

In most cases yes. Because the ceramic insulator sensor is installed on the equipment while it remains energised, the work is normally carried out as a live-line operation by qualified personnel following the site safety rules. Where a sensor must be coupled to an earthed screen, bonded connection or gas compartment, a short outage may be required — this is confirmed during the site survey.

Does HUWOR support OEM/ODM and what is the delivery lead time?

Yes. Zhuhai Huawang Technology Co., Ltd. supplies the ceramic insulator sensor under its own brand and also supports OEM/ODM supply, including private labelling, custom firmware functions and integration with the customer’s monitoring platform. Standard units are typically quoted with a lead time confirmed at order stage depending on quantity and configuration; sample and pilot orders are supported.

Applications

The ceramic insulator sensor is used for continuous online partial discharge monitoring of HV switchgear and cables. Typical installation sites include HV switchgear, cable terminations, GIS and transformer bushings. It is applied both on new assets, where the monitoring function is built into the asset from the start, and on existing assets where it is retrofitted to extend the information available to the maintenance team.

How it works

The instrument converts the physical quantity of interest into an electrical signal, conditions and digitises that signal in the field unit, and passes the result to the monitoring platform or to the operator. Condition assessment relies on the trend rather than on a single reading: the value recorded today is compared with the commissioning value and with the historical series for the same measurement point, and it is the direction and rate of change that indicate whether the asset is degrading.

Installation and commissioning

Installation follows three steps: a site survey to confirm the mounting position, the communication path and the power arrangement; mechanical fitting of the sensor or the use of the instrument on the test point; and finally commissioning, where the readings are verified against a reference and the alarm thresholds are set.

Standards and documentation

Type test reports, calibration certificates and installation documentation are provided with the supply. Where a project requires the equipment to be verified against a specific national or utility standard, the applicable clauses should be stated in the enquiry so that the test scope can be confirmed at quotation stage.