Third Party Inspection for Control Panel - Procedure

The Third Party Inspection for Control Panel article provides a sample procedure for control panel testing and control panel inspection in the  manufacturing shop. You might need to review this article with the control panel inspection and test plan

This content guides you through all the necessary stages in the production of the control panels, including the raw material, final inspection, preservation and packing, and dispatch to site. You need to take this point into account: this article is written for a typical control panel and might not be detailed for special cases.

All control panel inspection and testing is done against the approved drawings, purchase order specifications, purchasers or company standards, and within the practices and rules of the country, state or province and any government decrees, laws, ordinance or regulation as may apply.

Third Party Inspection for Control Panel

The applicable codes and specifications for a control panel that is under the construction process is:

  • Design code
  • Purchase order specification
  • Purchaser's standards
  • Approved drawings

The applicable codes and standards may be based any international standards. This content is general and can be useful for all recognized standards.

Required Documents for Third Party Inspector Review:

The list of documents normally is agreed upon in the Pre-Inspection meeting, which is held several weeks before the actual commencement of the inspection work. The parties that participate in this meeting are the manufacturer, purchaser and third party inspection agency representatives.

These are the list of documents that are normally agreed upon to be presented to the inspector:

Third Party Inspection for Control Panel - Material Inspection

The first actual inspection work in the control panel is the raw materials inspection.

The original or authenticated copies of mill certificates of material normally are available at the manufacturer's premises.

The third party inspector examines these certificates for compliance with specifications, and where appropriate, drawings.

The review includes checks on:

Then the inspector witnesses the materials identification on the certificates against the materials marking. It is also necessary to check these with the control panel drawing datasheet, material list and other specifications as appropriate.

Visual inspection for surface finish and probable defects is done and dimensional compliance with specification need to be controlled, as well.

When the third party inspector carries out the material inspection, then provides the inspection visit report (IVR), the report contains the following items:

  • Confirmation of satisfactory document review
  • Record of the endorsement of certification reviewed/witnessed
  • Record of all non-conformities
  • Record of any tests witnessed and the result

Third Party Inspection for Control Panel Construction

When the control panel raw material inspection is carried out, and the results were satisfactory or non-conformities were closed by remedial action, then the control panel manufacturer will start fabrication.

The third party inspector checks the following points on the control panel, based on the inspection and test plan (ITP), which has already been agreed upon between the purchaser and the control panel manufacturer.

The inspection scope is determined in the ITP. Some purchasers prefer to have stringent controls and assign the TPI for more “hold or witness points” for inspection and test activities, and some others prefer less “hold or witness points” and assign the TPI much more work in the “review document.”

This depends in the inspection budget, which purchasers assign for inspection. Much more inspection will have a much larger cost and less risk, and conversely, less inspection will have less cost but more risks.

The third party inspector checks the following items in the control panel casing inspection process:

  • Paint inspection including blast cleaning (SSPC-SP 10 or 5), surface profile, Dry film thickness, colour, etc. 
  • Name plate control
  • Outline dimensions, interface dimensions, bus bar dimensions and Clearances and other specified dimensions
  • Tightness/torque of terminals
  • Degree of protection

It is necessary the results to meet drawings and applicable standards.

Third Party Inspection for Control Panel - General Arrangement Check

The third party inspector checks that all instruments, compartments, control switches etc. are correctly rated and are correctly located, with specified labelling in accordance of approved drawings.

Third Party Inspection for Control Panel - Insulation Resistance Test

Insulation resistance is measured between control circuits and earth (with sensitive devises excluded) with a 500V Megger.

Similarly, insulation resistance is measured in all applicable permutations for any power circuits, if these are included within the control system, with a Megger selected to the voltage calculated appropriate to the applicable specification.

The test result depends to the circuit but would not be acceptable if it is less than 2 Megohms.

Third Party Inspection for Control Panel - Withstand Voltage Test (Dialectric Test)

Power frequency voltage of 1.5 kV is applied between control circuits and earth for 1 minute. Similarly power frequency voltage, calculated appropriate to the applicable specification, is applied to all applicable permutations for power circuits for 1 minute.

The test would be acceptable if the no flashover and puncture occurs during the test.

Third Party Inspection for Control Panel Sequence Test

Control circuitry is functionally tested and circuits proven by appropriate tests.The test result would be acceptable if meet approved schematic diagrams (including appropriate, recorded, “as built” alterations) and project philosophy

Third Party Inspection for Control Panel Mechanical Operation Test

The following mechanisms are checked for operation:

  • Locking
  • Interlocking systems
  • Drawing mechanisms
  • Opening and shutting mechanisms
  • Interchangeability.

The test would be acceptable if all the mechanisms work correctly.

Third Party Inspection for Control Panel - Painting and Coating Inspection

Surface preparation for painting is checked for the following points, according to specification by third party inspector:

  • Cleaning method (Blast or scraping and wire brushing)
  • Preparation grades
  • Freedom from weld spatter, blow-holes and other defects
  • Dry film thickness is checked according to specification

It is necessary surface condition to be free from pin-holes, runs damage and other discontinuity.

Third Party Inspection for Control Panel - Reporting

The third party inspector provides an Inspection Visit Report (IVR) after each visit, as well as a final report summarizing the activities carried out during the control panel production in accordance with the contract requirements and circulated within the time limits specified in the contract.

The report is in the format required by the client and clearly indicates final acceptance or rejection of the control panel.

Third Party Inspection for Control Panel - Release Note

When required by the contract or purchase order, a release note is issued by the third party inspection agency and given to the manufacturer when the control panels have been accepted.

Third Party Inspection for Control Panel Packing, Marking and Shipping

The following points are checked by the third party inspector:

  • Verify that the packing materials conform to specifications and accepted practice for the mode of transport.
  • Verify protection against humidity, abrasion, distortion and other damage.
  • Verify shipping marks to marking instructions and record.
  • Verify handling marks.