⚡ Electric and optical fibre cables — thermal stability test of PVC insulations and PVC sheaths: three samples of (50 ± 5) mg in glass tubes at the temperature from the cable standard or at (200 ± 0.5) °C, measurement of the time until universal indicator paper changes colour from pH 5 to pH 2–3; PN-EN 60811-405

Electronics and EMC PN-EN 60811-405

Overview

WHAT THE STANDARD COVERS. According to clause 1 of IEC 60811-405:2012 this part of the IEC 60811 series specifies the procedure for the thermal stability test which applies to PVC compounds. The IEC 60811 series (introduction) specifies test methods for non-metallic materials of all types of cables — insulation, sheaths, fillers, tapes — intended to be referenced in cable construction standards and in material standards. Part 405 is used together with IEC 60811-100 (general part). "Scope" field of the PKN card for PN-EN 60811-405:2012 (English version, description in Polish): "The procedure for checking the thermal stability of insulations and sheaths made of PVC is described. The test consists in measuring the time needed for the pH value of the samples to change at a specified temperature from 5 to between 2 and 3. The samples are placed in a glass tube and then in a heating apparatus. Universal indicator paper is used to measure the pH".

ACCORDING TO THE TEXT OF IEC 60811-405:2012 — EDITION, APPARATUS, PROCEDURE (foreword, introduction, clauses 1–5, bibliography). The standard was prepared by IEC TC 20 (Electric cables); edition 1.0 of 2012-03. It cancels and replaces Clause 9 of IEC 60811-3-2:1985, which is withdrawn; according to the foreword there are no specific technical changes with respect to the previous edition, and full details of the replacements are shown in Annex A of IEC 60811-100:2012. Normative references: IEC 60811-100:2012, ISO 695:1991, ISO 719:1985 and ISO 1776:1985 (requirements for the glass of the tubes). Tests are carried out at room temperature unless otherwise specified (4.1). Apparatus (4.2): a) glass tubes closed at one end (e.g. by melting), 110 mm long, with an outer diameter of approximately 5 mm and an inner diameter of (4.0 ± 0.5) mm, made of AR-glass complying with ISO 695:1991 (alkali resistance, Class A2), ISO 719:1985 (hydrolytic resistance, Class HGB3) and ISO 1776:1985 (acid resistance, maximum weight loss 150 µg Na2O/100 cm2); b) universal indicating paper with a pH range of 1 to 10; c) a thermostatically controlled heating apparatus for the temperature specified in the cable standard or, if none is specified there, (200 ± 0.5) °C; an oil bath is preferred and shall be used for type tests and in case of doubt; d) a calibrated thermometer with divisions of 0.1 °C (depending on the type of thermometer a mercury column correction may be necessary); e) a stop-watch or other time meter. Pre-conditioning (4.3): the tests are carried out not less than 16 h after extrusion of the insulating or sheathing compound. Procedure (4.4): a) three samples of (50 ± 5) mg each are taken from the insulation of each core tested or from the sheath tested, each consisting of two or three small strips 20 mm to 30 mm long; the sample occupies no more than the bottom 30 mm of the tube; b) a strip of dry indicator paper about 15 mm by 3 mm is inserted into the open end of the tube so that it protrudes about 5 mm and can be bent to keep it in position; c) the tube is placed into the heating apparatus, which has already attained the test temperature, to a depth of 60 mm; d) the time taken for the paper to change colour from pH 5 to a value between pH 2 and pH 3 is measured — or the test is continued for the specified duration without the colour change occurring; the change point is reached when the red colouring characteristic of pH 3 is just becoming visible; for long tests the paper is renewed towards the end of the expected time every 5–10 min so that the change point is better visible. Note in 4.4: an accurate thermometer and compliance with the test temperature limits are necessary for reliable results and to restrict scatter. Evaluation (4.5): the average thermal stability time of the three samples shall not be lower than the value specified in the standard for the type of cable. Test report (clause 5) — according to IEC 60811-100.

STATUS (PKN cards as of 10.11.2026). The card for PN-EN 60811-405:2012 (English version) has no withdrawal label: published 01-10-2012, 11 pages, KT 53 for Cables and Wires, "Implements: EN 60811-405:2012 [IDT], IEC 60811-405:2012 [IDT]", "Replaces: PN-EN 60811-3-2:1999 - Polish version, PN-EN 60811-3-2:1999/A2:2005 - Polish version, PN-EN 60811-3-2:1999/Ap1:2006 - Polish version", ICS 29.060.20, 29.035.01. The PKN search (query "PN-EN 60811-405", 10.11.2026) shows only this card. iTeh catalogue (read 10.11.2026): IEC 60811-405:2012 — published 12.03.2012, stage PPUB; SIST EN 60811-405:2012 (EN 60811-405:2012) — European foreword: CENELEC approved EN 60811-405 on 16.04.2012; it partially supersedes EN 60811-3-2:1995 and A2:2004.

HOW MANY LABORATORIES AND IN WHAT FORM (accreditation scope database of the service and the "Laboratories" tab on labcoda.pl, read 10.11.2026). The number 60811-405 appears in 6 records at 6 Polish laboratories, 1 record each: AB 044 ("PN-EN 60811-405:2012 | EN 60811-405:2012 | IEC 60811-405:2012"), AB 261 ("PN-EN 60811-405:2012" next to PN-EN 60811-3-2:1999 with A2:2005 and Ap1:2006), AB 1917 (in the list of standards for cables and cable accessories), AB 1776, AB 1814 and AB 1974 ("IEC 60811-405:2012" next to automotive industry specifications LV 112, LV 212 or VW 60306 and VW 75210 with clause numbers). Outside Poland — 3 records at 3 Czech laboratories (1056, 1754, 1773: "ČSN EN 60811-405"). The "Laboratories" tab ("PN-EN 60811-405") shows the same 9 laboratories (6 PL, 3 CZ), 1 item each. We have not compared the current PCA scope documents of these laboratories with the database.

WHAT THE LABORATORIES TEST (scope database, complete items — 6 Polish). AB 044 — power cables and wires: thermal stability of PVC insulations and sheaths, up to 200 °C. AB 261 — cables and wires with rated voltage up to 18/30 kV and outer diameter up to 100 mm: thermal stability of insulation and sheath. AB 1776, AB 1814 and AB 1974 — cables: thermal stability of PVC. AB 1917 — cables and cable accessories with Un from 3.6 to 500 kV: the item "Checking the mechanical properties of materials" with a long list of standards, including 60811-405.

WHERE AN APPARENTLY CORRECT RESULT IS EASY TO GET. Sampling: testing earlier than 16 h after extrusion does not meet 4.3; a sample outside (50 ± 5) mg, made of one strip instead of two or three, of strips shorter than 20 mm or longer than 30 mm, or filling more than the bottom 30 mm of the tube means test conditions other than in 4.4. Measurement: the temperature is taken from the cable standard — (200 ± 0.5) °C is used only when the cable standard does not give one; for type tests and in case of doubt an oil bath is mandatory; the tube goes into an apparatus that is already heated, to a depth of 60 mm. The end point is the first visible red colouring of pH 3, not full discolouration; without renewing the paper every 5–10 min at the end of a long test the change point is easily missed and the time overstated. A tube of glass without the required resistance classes (A2, HGB3, loss up to 150 µg Na2O/100 cm2) — the standard requires AR-glass. Calculation: the criterion applies to the MEAN of three samples, and the limit is given by the cable standard — PN-EN 60811-405 itself gives no number.

WHAT WE DO NOT GIVE. Parts read: the iTeh sample of IEC 60811-405:2012 (full English text: foreword, introduction, clauses 1–5, bibliography) and the iTeh sample of SIST EN 60811-405:2012 (title page and European foreword). We do not give the terms and requirements of the general part IEC 60811-100 (to which the test report and terms refer) or the glass requirements of ISO 695, ISO 719 and ISO 1776 beyond the classes named in 4.2 — we have not read these standards. We do not give stability times or temperatures for particular types of cables — they are given in cable standards and customer specifications (e.g. LV 112, VW 60306 from the scopes), which we have not read. PKN has not issued a Polish language version of PN-EN 60811-405 (the search shows only the card of the English version).

Method principle

Three samples of (50 ± 5) mg (two or three strips 20–30 mm) from the PVC insulation of each core or from the sheath are heated in glass tubes (110 mm, inner diameter (4.0 ± 0.5) mm, AR-glass) with a strip of universal indicator paper at the open end, to a depth of 60 mm at the temperature from the cable standard or at (200 ± 0.5) °C (oil bath preferred); the result is the time until the paper changes colour from pH 5 to pH 2–3, and the mean of three samples shall not be lower than the value in the cable standard (IEC 60811-405:2012, 4.2–4.5).

Applications

• Core insulation and sheaths of PVC compounds of electric and optical fibre cables (IEC 60811-405:2012, clause 1 and introduction)
• Method referred to in cable standards and customer specifications, which give the temperature and the minimum stability time
• Replaced Clause 9 of IEC 60811-3-2:1985 (in PN — PN-EN 60811-3-2:1999 with A2:2005 and Ap1:2006) without technical changes
• In accreditation scopes: 6 Polish laboratories — power cables up to 18/30 kV and up to 500 kV, cables to automotive industry specifications

Key parameters

Standard

Standard number

PN-EN 60811-405:2012 (English version; implements EN 60811-405:2012 and IEC 60811-405:2012 [IDT])

Title (PL)

Kable i przewody elektryczne oraz światłowodowe — Metody badań materiałów niemetalowych — Część 405: Badania różne — Sprawdzenie wytrzymałości cieplnej izolacji wykonanej z PVC i powłok wykonanych z PVC

Title (EN)

Electric and optical fibre cables — Test methods for non-metallic materials — Part 405: Miscellaneous tests — Thermal stability test for PVC insulations and PVC sheaths

Step-by-step procedure

1. Samples

   Not earlier than 16 h after extrusion; from the insulation of each core tested or from the sheath 3 samples of (50 ± 5) mg, each of 2–3 strips 20–30 mm long; the sample occupies at most the bottom 30 mm of the tube (4.3, 4.4 a).

2. Indicator paper

   Dry strip approx. 15 mm × 3 mm in the open end of the tube, protruding approx. 5 mm and bent (4.4 b).

3. Heating

   Tube into the apparatus that has already reached the test temperature (from the cable standard or (200 ± 0.5) °C), to a depth of 60 mm (4.4 c).

4. Time measurement

   Time until the colour changes from pH 5 to pH 2–3 — end point at the first visible red colouring of pH 3 — or the test continued for the specified duration without the colour change; at the end of a long test the paper is renewed every 5–10 min (4.4 d).

5. Evaluation and test report

   Mean time of three samples against the value from the cable standard; test report according to IEC 60811-100 (4.5, clause 5). PN-EN 60811-405:2012 — current (PKN card as of 10.11.2026; English version).

Required equipment and apparatus

Health and safety (OHS)

• Oil bath and tubes at a temperature of the order of 200 °C — protection against burns when inserting and removing the tubes
• Heating PVC — the change of the paper to pH 2–3 means that acidic decomposition products are released from the sample; the standard gives no ventilation requirements — NOT GIVEN
• TECHNICAL NOTE: the temperature and the minimum time are given by the cable standard; (200 ± 0.5) °C is used only when the cable standard gives no temperature

Frequently asked questions