Partial Discharge PD Acoustic Imaging Inspections

Partial Discharge PD Acoustic Imaging Inspections

Why detect and monitor Partial Discharge on High Voltage (HV) systems?

Partial Discharge (PD) is a localised electrical discharge that ‘partially’ bridges the insulation between conductors. Detecting and monitoring partial discharges is essential to preventing a full discharge event where the insulator breaks down causing catastrophic failure of high voltage equipment resulting in significant power outages, property damage and possible injury to personnel in the vicinity.

How can an acoustic imager be used to detect PD?

Components where PD is occurring, emit high frequency sound that is inaudible to human hearing but can be detected, measured, and sampled using ultrasonic acoustic imagers. An acoustic imager is a device that visually displays the source location of ultrasonic sound waves in real-time on a visual image. Their use enables PD to be detected and located on the insulators and bushings of HV transformers, circuit breakers, cables and busbars.

PD Inspection & Monitoring Survey Methodology

Red Current’s PD inspection surveys combine the use of acoustic imaging with thermography to provide a comprehensive overview of equipment performance, enabling early detection and continuous monitoring of PD issues. Our reports provide a clear understanding of the cause and location of defects together with a severity assessment that assists with the planned approach and scheduling of any remedial works.

Our survey approach has been tailored over many years to ensure the inspections are carried out safely and non-intrusively, causing no disruption to business operations whilst providing a full audit trail of the health of the equipment that has been inspected.

Each inspection is fully risk assessed with clear method statements and completed by PCN/ITC certified thermographers (ISO 18436:7). A systematic approach is applied to each individual substation to ensure all energised HV assets are inspected and examined for defects that are often detected for the specific equipment.

Our survey reports clearly present all defects that are identified together with providing commentary regarding suspected causes, recommended remedial action together with guidance on how to prioritise the urgency of remedial works.

PD Sample Report Page

Please contact us if you require a sample report.

Why choose Red Current Ltd?

Choosing Red Current Ltd will ensure full compliance with the requirements of the inspection, whilst realising the full benefits of acoustic imaging and electrical thermography. All our inspections are completed by highly trained, High Voltage (HV) experienced personnel using high specification acoustic and thermal imaging cameras.

At Red Current Ltd, we prioritise customer satisfaction and truly believe this to be the most fundamental quality of a sustainable business. Our commitment to excellence is not just a promise; it's validated by the trust and satisfaction of our valued clients. We take pride in our 5-star Google and Trustpilot reviews, a testament to the unwavering quality of our services and the positive experiences our clients have had.

Ensure the resilience of your High Voltage equipment with Red Current Ltd.’s unmatched acoustic & thermal imaging survey services. Contact us today and take the first step toward a more reliable and optimised infrastructure.

If you are interested in having a high voltage electrical thermal imaging survey, Red Current can provide an estimate price within an hour via email. By entering details such as company name, post code and estimated number of assets or days on site, you can apply for an estimate price so you know straight away whether our electrical thermal imaging surveys are the right price for you.

Electrical Thermal Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following details regarding the site location and survey duration.

An electrical thermal imaging survey can inspect up to 70 assets (fuse boards, MCB boards, control panels etc.) per day. Please select an approximate amount of electrical assets to be inspected or the number of days expected to complete the on-site survey.

Enter any additional details you think are relevant.

High Voltage Thermal Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following details regarding the site location and survey duration.

A thermal imaging survey for High Voltage Substations can typically examine 2 - 3 substations within a 20-mile radius per day. Please estimate the number of days required to complete the on-site survey(s).

Enter any additional details you think are relevant.

Buildings Thermal Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following information in relation to building to be surveyed.

Please provide estimated building dimensions and configuration.

Enter any additional details you think are relevant.

Mechanical Thermal Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following details regarding the site location and survey duration.

A mechanical thermal imaging survey can inspect up 70 assets (motors, pumps, fan-sets etc.) per day. Please select an approximate amount of mechanical assets to be inspected or the number of days expected to complete the on-site survey

Enter any additional details you think are relevant.

Under Floor Thermal Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following information in relation to building to be surveyed.

Please provide an estimated scope of work for the inspection

Enter any additional details you think are relevant.

Housing Thermal Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following information in relation to building to be surveyed.

Please provide estimated building dimensions and configuration.

Enter any additional details you think are relevant.

Leak Detection Thermal Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following information in relation to building to be surveyed.

Please provide an estimated scope of work for the inspection

Enter any additional details you think are relevant.

High Voltage Acoustic Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following details regarding the site location and survey duration.

An acoustic imaging survey for High Voltage Substations can typically examine 2 - 3 substations within a 20-mile radius per day. Please estimate the number of days required to complete the on-site survey(s).

Enter any additional details you think are relevant.

Compressed Air Acoustic Imaging Survey Enquiry Form

Please complete the form below to let us know your requirements. We’ll then provide detailed information on costs and our inspection process.


Please provide the following details regarding the site location and survey duration.

Enter any additional details you think are relevant.

Camera Sales Enquiry

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Camera Sales Enquiry

Please fill out this form for us to generate an invoice. Call us on 0118 3320819 or email your enquiry to our team who are on hand to assist.


Enter any additional details you think are relevant.

Data Privacy: To find out how we process the data that you submit to us via this form, please read this Privacy Statement.

Camera Sales Enquiry

Please complete the form below to discover our latest offers on the camera you're interested in.



We’re committed to offering the best value on our cameras.

If you’ve received a quote elsewhere, let us know the price and the provider - we’ll do our best to exceed it with a like-for-like offer.


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Camera Hire Enquiry Form

Please complete the form below to let us know your requirements. We’ll provide detailed information on pricing, availability, delivery options, and our thermal camera hire process.


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Once submitted, a member of our team will get in touch with tailored guidance to support your needs.