IEC 61557-5-2019 PDF

Full title and description

IEC 61557-5:2019 — Electrical safety in low voltage distribution systems up to 1 000 V AC and 1 500 V DC — Equipment for testing, measuring or monitoring of protective measures — Part 5: Resistance to earth. This part specifies requirements for measuring equipment that determines the resistance to earth (earth resistance) using an AC test voltage; it covers performance, marking, safety and required tests for instruments and clamps intended for earth-resistance and earth-loop measurements.

Abstract

IEC 61557-5:2019 is the third edition (2019) and is a technical revision of the previous 2007 edition. It defines functional and safety requirements for earth-resistance testers (including loop clamps), clarifies definitions and symbols, aligns clause structure with other parts of IEC 61557, updates requirements on output and disturbance voltages, introduces requirements for clamps and marking (rated voltages to earth, measurement category), and replaces “percentage operating uncertainty” with the defined term “operating uncertainty.”

General information

• Status: Current international standard (third edition, technical revision).
• Publication date: July 2019 (Edition 3.0 — 2019-07).
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 17.220.20; 29.080.01; 29.240.01.
• Edition / version: Edition 3.0 (2019).
• Number of pages: 24 (standard PDF); redline/track-changes redline variant published by some bodies is longer (example redline listing shows 38 pages).

Scope

This part of IEC 61557 specifies requirements applicable to measuring equipment for measuring the resistance to earth (the real part of the impedance to earth) using an AC voltage, for low-voltage distribution systems with nominal voltages up to 1 000 V AC and 1 500 V DC. It applies to instruments that use auxiliary earth electrodes (current and potential probes), clamps intended for earth-loop/resistance measurements, and equipment intended for portable and bench use where relevant. The standard is to be used together with IEC 61557-1 (general requirements) and other series parts as applicable.

Key topics and requirements

• Definitions and symbols clarifications (alignment with series terminology).
• Output/test voltage requirements — AC output without DC component; frequency and waveform selection to minimise interference.
• Disturbance and series-interference voltages — manufacturer must state influence levels and limits in instructions.
• Operating uncertainty — maximum permissible operating uncertainty within marked ranges; revised uncertainty calculation.
• Probes and auxiliary electrode requirements — permissible probe/auxiliary resistances, terminal marking (E, H, S, ES) and capability to indicate exceeded probe resistance.
• Requirements and informative test arrangement for clamps and earth-loop testing (new Annex A for loop clamps).
• Marking and instructions — rated voltages to earth, measurement category, warnings (including absence of hazardous voltage) and clear operating instructions.
• Electrical safety — limits on open-circuit output voltage and short-circuit current, and automatic-disconnection requirements when limits are exceeded; tests to verify safety and overload protection.
• Type and routine tests — tests for operating uncertainty, electrical safety, probe-resistance indication and clamp test configurations.

Typical use and users

Manufacturers of earth-resistance testers, earth-loop/clamp testers and other protective-measure test equipment use this standard to design, mark and document instruments. Calibration and test laboratories use it for verification and type/routine testing. Electrical installers, verification/inspection engineers, maintenance teams and safety assessors use the requirements and marked instrument performance data when testing earthing/grounding arrangements in low-voltage installations. Certification bodies and conformity assessment organisations use it as part of product assessment.

Related standards

IEC 61557-5 is part of the IEC 61557 series and is intended to be used with IEC 61557-1 (general requirements). Other related documents commonly referenced include IEC 61010-1 (safety requirements for measurement equipment), IEC 60364-6 (verification of low-voltage installations), and other IEC 61557 parts (insulation resistance, loop impedance, RCD testing, phase-sequence, etc.). National or regional adoptions include EN/AFNOR/NF adoptions (EN IEC 61557-5) and national redline variants.

Keywords

earth resistance, resistance to earth, earth loop, earth electrode, auxiliary earth electrode, probe electrode, operating uncertainty, loop clamps, low-voltage distribution systems, IEC 61557, measurement equipment, electrical safety, marking, test methods.

FAQ

Q: What is this standard?

A: IEC 61557-5:2019 is the third edition (2019) of the IEC standard that specifies requirements for equipment used to measure resistance to earth (earth resistance) using an AC test voltage in low-voltage distribution systems.

Q: What does it cover?

A: It covers functional performance, safety limits, marking and operating instructions, uncertainty requirements, permissible probe/auxiliary-electrode conditions, clamp/test configurations and the type/routine tests required to demonstrate compliance for earth-resistance and earth-loop measurement equipment.

Q: Who typically uses it?

A: Device manufacturers, test and calibration laboratories, electrical installers and verification engineers, maintenance teams, certification bodies and conformity assessment organisations, and safety assessors involved in earthing/grounding measurements.

Q: Is it current or superseded?

A: IEC 61557-5:2019 replaced IEC 61557-5:2007 when published in July 2019 (Edition 3.0). The 2019 edition is the current IEC edition; a redline/track-changes variant is published by some national bodies. (Users should check national adoption or amendments where applicable and confirm status with their national standards body if they need definitive legal/regulatory applicability.)

Q: Is it part of a series?

A: Yes — it is Part 5 of the IEC 61557 series (Equipment for testing, measuring or monitoring of protective measures in low-voltage distribution systems); related parts (for example IEC 61557-1, -2, -3, -4, -6, -7, -12, etc.) cover general requirements and other specific measurement functions.

Q: What are the key keywords?

A: Earth resistance; resistance to earth; earth loop; probe electrode; auxiliary earth electrode; loop clamp; operating uncertainty; low-voltage distribution; measuring equipment; marking; electrical safety.