KEY POINTS
- รง.4 is a factory operating licence, not an electrical inspection report.
- Keep inspection records and current drawings together.
- Assign responsibility and verification for every corrective action.
An electrical inspection should leave the factory team with a usable record of the installation, findings and required follow-up work. Start by separating the factory’s operating licence from its electrical inspection documents; they serve different purposes.
What รง.4 refers to
รง.4 is a factory operating licence. The BOI’s post-promotion guidance identifies it among licences from the relevant authorities. It is not the name of a thermal-scan report or a certificate that an electrical installation has passed inspection.
Confirm the site’s factory classification and applicable requirements with the responsible authority. Do not determine the full inspection scope from a licence number alone.
Where the annual inspection requirement comes from
Clause 5 of the Ministry of Industry’s 2007 regulation on electrical safety in factories requires annual inspection and safety certification of factory electrical systems, with documentary evidence, by an engineer or another person designated under the regulation. The regulation also addresses records and current as-built drawings, with qualifications and exceptions set out in its text.
Confirm the currently applicable reporting procedure, form and inspector’s eligibility for the site. The Council of Engineers service portal provides access to its licence-information services. A person’s job title or employment inside the factory does not, by itself, establish authority to certify the work.
Prepare the information before the visit
- Current single-line diagrams, board schedules and a list of modifications.
- Equipment identification, ratings and available manufacturer instructions.
- Previous inspection reports and evidence of repairs already completed.
- Maintenance history, recurring trips, alarms and operating concerns.
- Site access, isolation requirements and the operating conditions needed for the agreed checks.
Discuss missing records early. If a diagram does not match the installation, identify the affected area so verification and drawing updates can be planned.
Agree the inspection and report scope
Ask which systems will be inspected, which measurements are required and what cannot be accessed during the visit. The report should connect each finding to an identifiable asset or location and state any limitations on the inspection.
Thermal imaging can support the review, but it does not replace the other checks required for the installation. See our guide to thermal scanning and maintenance records.
Close the loop after inspection
Maintain a register with the finding, assessed priority, responsible person, proposed action and evidence of completion. Agree how the result will be checked after repair and keep unresolved items visible. Store the report with revised drawings and the records needed for the next inspection.
ETES can discuss testing, fault finding and corrective work within an agreed maintenance scope. Confirm any statutory inspection or certification service explicitly in the proposal.
Common questions
Does a thermal image prove the whole installation is safe?
No. It records a temperature pattern under particular conditions. The inspection needs to consider the installation and all applicable checks together.
What if records are incomplete?
Provide the available documents and identify the gaps. Agree what must be verified or recreated before a report can accurately describe the installation.
Should repairs wait until the next annual inspection?
Have the responsible engineer assess findings and set the appropriate action and timing. An annual inspection schedule is not a reason to leave an identified problem unaddressed.
ETES services for this work
References & further reading
Primary publications used in this guide. Confirm the requirements and editions applicable to your project.
Send ETES your site location, equipment details and planned schedule. Our team can discuss the work required.
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