Low Voltage Grounding Installation Periodic Inspection Report (ZPKR01) and Criteria (ZPKK01): Ministry Format

Ministry of Labor and Social Security, low voltage grounding system a mandatory report format for periodic inspectionsZPKR01) and control criteria document (ZPKK01(published. The documents were published on July 18, 2025; 01.09.2025 From [date] onwards, the complete use of this format, both in form and content, is mandatory. The format is based on Article 14/B of the Work Equipment Regulation; the main headings and their order remain unchanged, while the size and layout of the content may be adapted. This page summarizes, based on the documentation, what the criteria are looking for and the sections the report consists of.

Scope and report preparation rules

• This document covers the periodic inspections of equipment located in facilities subject to the Electrical Installation Regulations.
• “The "Electrical Internal Installation Visual Inspection and Functional Tests Periodic Inspection Report" is a supplementary report for these periodic inspections. This report alone cannot be used for conformity assessment.
• The inspection report must be prepared separately for each piece of equipment (panel). If the panels are grouped together, a single report can be prepared.
• The findings of non-conformity can be illustrated with photographs as an appendix to the report.
• Findings from group boards should be explained in the notes section along with the board number.
• (ZPKR01) In facilities with a large number of points, multiple forms may be used, or only section 5 of the form may be duplicated.
• (ZPKR01) The evaluation was made as “Suitable”, “Not Suitable” and “Not Applicable”.
• (ZPKR01) Periodic inspection method and scope: TS HD 60364-4-41, TS HD 60364-6, Regulation on Health and Safety Conditions in the Use of Work Equipment, Regulation on Grounding in Electrical Installations, Regulation on Electrical Internal Installations.
• (ZPKR01) Conclusion and opinion: Following the inspection of the low-voltage grounding system, its use under existing conditions is deemed SUITABLE / NOT SUITABLE for a period of 1 year.
• (ZPKR01) Minor defects identified must be rectified by the next periodic inspection date; this note will only be written if minor defects are identified.

Control criteria (ZPKK01)

Limit values and thresholds in the document

• Measurement point: Measurements are taken from all points with touch voltages of <1000 V and >50 V (ZPKK01 Criterion 1).
• Potential equalization/continuity: checked between energized equipment at measurement points and de-energized metal pipes, etc., within a 2.5 m reach (ZPKK01 Criterion 1).
• Protective conductor cross-section: For circuits smaller than 63 A, it is checked according to the phase cross-section from the table; for circuits larger than 63 A, it is checked according to the heating control (ZPKK01 Criterion 2).
• Ground short-circuit current: This is calculated by dividing the measured 230 V voltage by the loop impedance; for example, for a loop impedance of 2 Ω, Ik = 115 A (ZPKK01 Criterion 3).
• 30 mA RCD: In TT or TN (TN-S or TN-CS section S) systems, the use of a 30 mA RCD is mandatory in general use socket installations up to 32 A and in portable appliance sockets up to 32 A (ZPKK01 Criterion 6; ZPKR01 Note-5, serious defect).
• In circuits exceeding 32 A where natural leakage currents are unavoidable, appropriately selected RCDs must be used in conjunction with other electric shock protection measures; they are insufficient if natural leakage current verification has not been performed (ZPKK01 Criterion 6; ZPKR01 Note-5, Note-6, gross negligence).
• The RCD tripping current must not exceed the tripping current stated on the device label, and the tripping time must not exceed 200 milliseconds (ZPKK01 Criterion 7); TΔ: Maximum test tripping time for RCD: 200 ms (ZPKR01 Section 4).
• Tests of toroidal current transformer RCDs with tripping thresholds above 1000 mA are performed by pressing the test button (ZPKK01 Criterion 7).
• At all consumption points supplied with low voltage, it must be verified by measurement whether the voltage exceeds 50 V for alternating current and 42 V for direct current (ZPKK01 Criterion 8).
• Touch voltage limit value 50 V: LV installation at AC, normal or dry locations (ZPKR01 Section 4).
• Touch voltage limit value 25 V: For low voltage installations, high-risk areas, wet areas, agricultural areas, etc. (ZPKR01 Section 4).
• 230 V (Uo): phase-to-ground or phase-to-neutral voltage to be used for calculations (ZPKR01 Section 4).
• TN networks: Zs < 230V/Ia — calculated loop impedance limit value; safety requirement against indirect contact for TN networks (ZPKR01 Section 4).
• TT networks: RA＜50V/Ia — calculated grounding resistance limit value; safety requirement against indirect contact for TT networks (ZPKR01 Section 4).
• Option for protection against indirect contact: Low voltage <50 V (ZPKR01 Section 2.1).
• Conclusion and opinion: suitability for use is granted for a period of 1 year (ZPKR01 Section 8).
• In TN installations, since the PEN conductor cross-section cannot be <10 mm², zeroing cannot be done in a 2.5 mm² socket; zeroing cannot be done in TT installations (ZPKR01 Note-10, serious defect).

Sections of the report format (ZPKR01)

• 1. COMPANY INFORMATION
• 2. EQUIPMENT INFORMATION (2.1. LABEL AND DETAIL INFORMATION; 2.2. IDENTIFIED INFORMATION)
• 3. INFORMATION ON MEASURING INSTRUMENTS
• 4. TEST VALUES
• 5. CONTROL CRITERIA AND TESTS (Measurement method; 5.1. CHECK FOR ADEQUACY OF PROTECTION AGAINST INDIRECT CONTACT AT FINAL CONSUMPTION POINTS; 5.2. SELECTIVITY CONTROL OF RESIDUAL CURRENT SWITCHES (RCDs))
• 6. DISCLOSURE OF DEFECTS
• 7. NOTES
• 8. CONCLUSION AND OPINION
• 9. INFORMATION AND APPROVAL OF THE PERSON AUTHORIZED TO CONDUCT PERIODIC INSPECTIONS.

The main information requested in the report is:

• Company information: Company Name, Periodic Inspection Address, Social Security Registration Number, Report Number, Report Date, OHS-KATIP Contract ID, Periodic Inspection Start Date and Time, Periodic Inspection End Date and Time, Next Periodic Inspection Date.
• Periodic Inspection Method and Scope (printed form): TS HD 60364-4-41 Low Voltage Electrical Installations – Part 4: Protection for Safety – Part 41: Protection Against Electric Shock; TS HD 60364-6 Low Voltage Electrical Installations – Part 6: Verification; Regulation on Health and Safety Conditions in the Use of Work Equipment; Regulation on Grounding in Electrical Installations; Regulation on Internal Electrical Installations.
• Label and details: Power supplier; Network type (TT / IT / TN; TN-CS / TN-C / TN-S); Network voltage; Is there a project for the facility? (Yes/No); Is there a single-line diagram? (Yes/No); Project information; Reason for inspection (Periodic Inspection / Initial Inspection); Grounding electrode type (Ring / Surface / Foundation / Deep / Undetermined); Building type (Residential / Commercial / Industrial / Other); Intended use of the equipment; Last inspection date.
• Options for protection against indirect contact: Equipotential grounding and automatic disconnection of the supply (TT, TN, IT); Protective insulation (Class II or ground insulation); Protective isolation (Isolation transformer); Low voltage <50 V.
• Environmental information: Weather and temperature; Soil moisture content.
• Information gathered: Are there any major changes to the installation? (Yes/No); Is there a previous periodic inspection label? (Yes/No); Panel/Equipment identification.
• Instrument information (side-by-side columns for two devices in the form): Device name, Calibration date, Calibration validity date, Serial number, Calibration number.
• Test value definitions (Section 4): Zx measured loop impedance; Zs limit loop impedance calculated according to the tripping current of the overcurrent protection device; Rx measured grounding resistance; RA limit grounding resistance calculated according to the tripping current of the overcurrent protection device; Ik phase-to-ground fault current calculated or measured according to the ground loop impedance in the circuit; Ia instantaneous tripping or automatic tripping current calculated according to the tripping curve type of the overcurrent protection device (for RCDs, the declared tripping current IΔn as stated on the label); IΔn RCD declared tripping current; IΔ RCD test tripping current; TΔ RCD test tripping time.
• Measurement and verification method options: Loop impedance; 3-terminal grounding; Clamp method (multiple grounding electrodes).
• 5.1 Columns of the table showing the adequacy of protection against indirect contact at the point of end consumption: No; Measurement point / Label or code; Protection element In (A), Tripping curve type, Tripping current Ia (A), Earth short-circuit current Ik1 (A); Measurement: Measured value Zx/Rx (Ω), Limit value Zs/RA (Ω); RCD type, withstand current and tripping current In(A) / IΔn(mA); RCD test: Trip current IΔ (mA), Trip time TΔ (ms); Result (Grade of conformity).
• 5.2 Columns of the Selectivity Control Table for Residual Current Devices (RCDs): No. (Rows N=1, N=2); Name of the panel N before the panel supplying the final consumption point; RCD label information used: RCD Type, Withstand current In (A), Trip current IΔn (mA), Trip time delay (ms); Name of the panel supplying the final consumption point; RCD used: RCD Type, Trip current IΔn (mA), Test trip time TΔ (ms); Result (Compliance grade).
• Free text areas for defect descriptions and notes (Sections 6 and 7).
• Conclusion and opinion: Suitable/Not Suitable for use for 1 year; note on remedying minor defects; suitability notes (Note-1 … Note-11).
• Authorized person information and confirmation: Full Name, Profession, Authorized Person Registration Number, Signature.
• The number of copies of the report prepared (in words and numbers).

Defect rating and notes in the document

• Note 1 (ZPKK01): The degree of defect is indicated by “*” for slightly defective and “**” for defective.
• Note 2 (ZPKK01): The criteria specified in the inspection content may vary depending on the equipment's place of use, purpose, type, model, etc. If the specified risks are not present in the equipment, based on the relevant manufacturing legislation and/or standard, the inspection criteria will not be sought. The decision on whether or not to seek a criterion for that equipment should be made by paying attention to the legislation and/or standard clauses referenced in the standard clause section; the type, model, year of manufacture, etc. of the equipment for which the criterion should be applied should be evaluated according to the legislation and/or standard clauses. The inclusion of a criterion in the inspection content does not mean that it is a mandatory criterion for every piece of equipment.
• Note 3 (ZPKK01): In grounding checks of electrical installations outside the panel (e.g., cable tray, connection check, junction box, building junction box, lighting fixture connection), the measurement point is numbered. If possible, it is marked on the site plan.
• Note 4 (ZPKK01): When thermal cameras are used for heating and connection point checks, no additional training is required unless otherwise specified by the Ministry.
• ZPKR01 Section 6: Degree of defect. “*” indicates minor defect and “**” indicates major defect. The evaluation was done as “Suitable”, “Not Suitable” and “Not Applicable”.
• ZPKR01 conformity rating Note-1: Compliant.
• ZPKR01 conformity rating Note-2: Not suitable due to failure to meet safety requirements. (Gross defect)
• ZPKR01 conformity note Note-3: Grounding connection is missing, must be checked. (Serious defect)
• ZPKR01 conformity rating Note-4: It is suitable because a residual current switch is used and is operational.
• ZPKR01 Conformity Note Note-5: In TT or TN (TN-S or TN-CS section S) network systems, the use of a 30 mA residual current device (RCD) is mandatory in general use socket installations up to 32 A and in portable appliance sockets up to 32 A. In circuits above 32 A, where natural leakage currents are unavoidable, appropriately selected residual current devices (RCDs) must be used in conjunction with other electric shock protection measures. Technical details and reasons for the sections where natural leakage occurs must be stated in the relevant sections of the periodic inspection report. (Gross defect)
• ZPKR01 conformity rating Note-6: Insufficient because, in addition to precautions against indirect contact, natural leakage current verification is not performed in circuits above 32 A. (Gross defect)
• ZPKR01 conformity rating Note-7: Insufficient because the RCD used in the panel preceding the panel supplying the final consumption point is not a delayed type (selective or delay adjustable).
• ZPKR01 conformity rating Note-8: Measurement could not be performed due to high neutral-ground voltage. (Serious defect)
• ZPKR01 conformity note Note-9: Combining PE and N conductors is not permitted except for the PEN bridge which specifies the TN-S and TN-CS grounding system types. (Serious defect)
• ZPKR01 conformity rating Note-10: Insufficient due to detected Neutral-Ground connection (grounding performed) on the socket. Grounding cannot be performed if the installation grounding type is TT. If it is TN, grounding cannot be performed in a 2.5 mm² socket because the PEN conductor cross-section cannot be <10 mm². (Serious defect)
• ZPKR01 conformity rating Note-11: Inadequate due to the absence of a panel body-cover bridge. (Serious defect)

The scope of AES Innovation

This inspection is covered by AES Innovation's TÜRKAK accreditation (TS EN ISO/IEC 17020, AB-0631-M). The Ministry requires accredited inspection bodies to include the organization's logo, trade name, and TÜRKAK accreditation mark on their reports in this format.

For the inspection to be carried out, a contract must be drawn up and approved between the employer and the authorized person conducting the inspection via the ISG-KATIP system at least one day prior to the inspection; a report issued without such a contract is invalid.

Relating to: Service page · ISG-KATIP contract and mandatory report formats · Work Equipment Regulation and Annex III

Sources

• Ministry of Labor and Social Security Work Equipment documents: ZPKK01 and ZPKR01 (Mandatory Documents)
• Ministry of Labor and Social Security: Mandatory periodic inspection report format and criteria for electrical group work equipment.

Frequently Asked Questions

Since when has the ZPKR01 format been mandatory?

According to the ministry's announcement, as of September 1, 2025, the complete and accurate use of this format, both in terms of form and content, is mandatory during periodic inspections of low-voltage grounding installations.

Can the format's appearance be changed?

The content can be used with the same size and layout as the main headings, but without changing their order.

Is every item in the criteria document required for every piece of equipment?

No. According to the document's note, the criteria may vary depending on the equipment's place of use, purpose, type, and model; whether or not a criterion is required for that equipment is determined by examining the relevant legislation and standard articles.