HD 605 S2:2008

SLOVENSKI STANDARD
01-marec-2009
1DGRPHãþD
SIST HD 605 S1:1998
SIST HD 605 S1:1998/A1:1998
SIST HD 605 S1:1998/A2:2002
SIST HD 605 S1:1998/A3:2002
SIST HD 605 S1:1998/A4:2005
(OHNWULþQLNDEOL'RGDWQHSUHVNXVQHPHWRGH
Electric cables - Additional test methods
Starkstromkabel - Ergänzende Prüfverfahren
Câbles électriques - Méthodes d’essais supplémentaires
Ta slovenski standard je istoveten z: HD 605 S2:2008
ICS:
29.060.20 Kabli Cables
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

HARMONIZATION DOCUMENT
HD 605 S2
DOCUMENT D'HARMONISATION
July 2008
HARMONISIERUNGSDOKUMENT
ICS 29.060.20 Supersedes HD 605 S1:1994 + A1:1996 + A2:2001 + A3:2002 + A4:2004

English version
Electric cables -
Additional test methods
Câbles électriques -  Starkstromkabel -
Méthodes d’essais supplémentaires Ergänzende Prüfverfahren

This Harmonization Document was approved by CENELEC on 2008-03-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for implementation of this
Harmonization Document at national level.

Up-to-date lists and bibliographical references concerning such national implementations may be obtained on
application to the Central Secretariat or to any CENELEC member.

This Harmonization Document exists in three official versions (English, French, German).

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. HD 605 S2:2008 E
Foreword
This Harmonization Document was prepared by the Technical Committee CENELEC TC 20, Electric cables.
The text of the draft was submitted to the Unique Acceptance Procedure and was approved by CENELEC as
HD 605 S2 on 2008-03-01.
This Harmonization Document supersedes HD 605 S1:1994 + A1:1996 + A2:2001 + A3:2002 + A4:2004.
It provides a full updating of edition 1, including incorporation of amendments 1, 2, 3 and 4 together with the
results from rationalisation of “Harder to harmonise” tests.
In order to maintain the integrity of existing clause numbers, and hence avoid unnecessary amendments to over
100 particular sections of the product HDs, the normative references are given in Annex A.
The numbering of tables and figures in this standard is not conventional. It retains the scheme as used in
HD 605 S1. This is to facilitate easier cross referencing in national sections of HD 603, HD 620 and other
compendia HDs. It also allows for continuing work to rationalise and harmonise more of these test methods in
the future, without the need for further re-numbering.
The following dates were fixed:
– latest date by which the existence of the HD
has to be announced at national level (doa) 2008-09-01
– latest date by which the HD has to be implemented
at national level by publication of a harmonized
national standard or by endorsement (dop) 2009-03-01
– latest date by which the national standards conflicting
with the HD have to be withdrawn (dow) 2009-03-01
__________
– 3 – HD 605 S2:2008
Contents
1 General . 8
1.1 Scope . 8
1.2 Applicable tests . 8
1.3 Classification of tests. 8
1.4 Sampling . 8
1.5 Test conditions . 8
1.5.1 Ambient temperature . 8
1.5.2 Tolerance on temperature values . 8
1.5.3 Frequency and waveform of power-frequency test voltages . 9
1.5.4 Pre-conditioning . 9
2 Non-electrical tests . 9
2.1 Dimensional measurements . 9
2.1.1 Measurement of insulation thickness . 9
2.1.2 Measurement of non-metallic sheath thickness. 9
2.1.3 Measurement of cable dimensions . 10
2.1.4 Measurement of wires, strips and tapes . 10
2.1.5 Measurement of thickness of metallic sheath . 11
2.1.6 Check of application of screen or armour tapes, or wires. 12
2.1.7 Percentage coverage of a braided metallic layer . 12
2.1.8 Measurement of the gap between non-metallic tapes of taped bedding . 13
2.1.9 Measurement of rubber layer thickness . 13
2.1.10 Irregularities of semi-conducting layers and insulation . 13
2.1.11 Dimensions of cores . 21
2.1.12 Wall thickness of sheath and thickness of armouring . 24
2.1.13 Dimensions of conductor . 24
2.1.14 Measurement of thickness of metallic sheath . 25
2.1.15 Measurement of overlap of screen or armour tapes . 25
2.2 Mechanical tests on non-metallic components . 27
2.2.1 Measurement of Shore D hardness of PE sheath . 27
2.2.2 Determination of tear resistance of the protective sheath . 29
2.2.3 Compression test . 32
2.2.4 Hot pressure test for insulation and sheath . 32
2.2.5 Determination of hardness for elastomeric insulation and sheath. . 33
2.2.6 Modulus tests . 33
2.2.7 (Spare) . 33
2.2.8 Strippability test on extruded semiconducting insulation screen . 33
2.2.9 Resistance to environment of sheath samples . 36
2.2.10 Resistance to environment of the sheath of the suspension strand (aerial cables). 37
2.2.11 Insulation screen cutting test . 38
2.2.12 Water immersion test on sheath . 38
2.2.13 Climatic withstand of the outer sheath . 38

2.3 Mechanical tests on metallic components . 41
2.3.1 Tensile test on metallic com ponents . 41
2.3.2 Wrapping test for galvanised steel wire . 41
2.3.3 Wire and strand strength and elongation at break (for aluminium-clad steel conductor
messengers) . 41
2.3.4 Torsion test . 42
2.4 Non-electrical tests on samples of complete cable . 42
2.4.1 Bend tests for complete cable. 42
2.4.2 Verifying the application of tapes for strip armour after bending. 47
2.4.3 Sheath penetration test . 47
2.4.4 Sheath shrinkage test . 48
2.4.5 Abrasion test . 54
2.4.6 Sheath cut-through test . 55
2.4.7 Crush test . 55
2.4.8 Behaviour of PVC sheath at low temperature . 56
2.4.9 Water penetration test . 56
2.4.10 Test for restriction of corrosion of neutral/earth conductor . 59
2.4.11 Performance of anti-corrosion layer after ageing . 59
2.4.12 Special compatibility tests . 60
2.4.13 Performance test at high temperature . 61
2.4.14 Conductor overheating test in duct . 61
2.4.15 Integrity of single rubber layer . 61
2.4.16 Test for withstanding climatic conditions for red PVC- or PE-outer sheath . 61
2.4.17 Sheath adhesion test to metal tape . 62
2.4.18 (Spare) . 65
2.4.19 Resistance against H S of PVC outer sheath . 65
2.4.20 Determination of UV stability of MDPE sheath . 65
2.4.21 Stress cracking test on PE sheath . 66
2.4.22 Abrasion test (conic piece) . 68
2.4.23 Resistance to UV rays. 69
2.4.24 Test method for measurement of rigidity of polymeric cables . 70
2.5 Physical and chemical tests . 76
2.5.1 Zinc coating . 76
2.5.2 Thermogravimetric test for non-metallic materials . 79
2.5.3 Checking tinning of copper wires . 80
2.5.4 Checking durability of colours and marking . 80
2.5.5 Water permeation test . 80
2.5.6 Water absorption determined by capacitance measurement . 83
2.5.7 Thermogravimetric test for insulating, filling and non-metallic sheathing materials . 84
2.5.8 Tests for carbon black content and/or mineral filler content and carbon black
dispersion . 84
2.5.9 Swell height of water blocking tape . 87
2.5.10 Measurement of water content of insulation . 88
2.5.11 Methods for determining density . 88
2.5.12 Artificial weathering test . 91
2.5.13 Abrasion test . 92
2.5.14 Wet compatibility test for type approval . 92
2.5.15 Degree of cross-linking of cross-linked polyethylene . 93

– 5 – HD 605 S2:2008
3 Electrical tests. 95
3.1 Electrical resistance . 95
3.1.1 Conductors . 95
3.1.2 Armouring . 95
3.1.3 Electrical resistance of combined armour and protective earth conductor . 97
3.1.4 Screen or concentric conductor special resistance test . 98
3.2 Voltage tests . 99
3.2.1 Tests on complete cable . 99
3.2.2 Tests on cores . 99
3.2.3 Tests on oversheath . 100
3.2.4 Impulse voltage test . 100
3.2.5 Special four hour voltage test . 100
3.2.6 A.C. breakdown voltage test . 100
3.2.7 Impulse breakdown voltage test . 104
3.2.8 50 Hz step voltage test . 105
3.3 Insulation resistance tests . 105
3.3.1 Insulation resistance test on insulated cores . 105
3.3.2 Insulation resistance test on screened or armoured complete cable. 107
3.3.3 Insulation resistance test on unscreened or unarmoured complete cable. 107
3.3.4 Oversheath resistance test on screened or armoured complete cable . 108
3.3.5 Method of test for insulation resistance constant (K value) of sheath . 108
3.4 Surface resistance of the cable oversheath . 108
3.4.1 Test equipment . 108
3.4.2 Testing . 108
3.5 Checking the insulating properties of cable filling compound . 109
3.5.1 Scope . 109
3.5.2 Procedure: . 109
3.6 Spark tests . 109
3.6.1 Method 1 . 109
3.6.2 Method 2 . 109
3.6.3 Method 3 . 109
3.6.4 Method 4 . 109
3.7 Measurement of transfer impedance . 110
3.7.1 Measurement arrangement . 110
3.7.2 Theoretical curve of transfer impedance . 110
3.8 Heating cycle test . 112
3.8.1 Method 1 . 112
3.8.2 Method 2 – Heating cycle voltage test . 112
3.8.3 Method 3 – Long duration test with thermal cycles . 112
3.8.4 Method 4 . 113
3.8.5 Method 5 . 115
3.8.6 Method 6 – Long term stability test . 115
3.9 Measurement of the electrical resistivity of the semi-conducting screens . 116
3.9.1 Method 1 . 116
3.9.2 Method 2 . 118
3.9.3 Method 3 . 118
3.9.4 Method 4 – Outer semi-conducting layer . 118

3.10 Partial discharge test . 118
3.10.1 Method 1 . 118
3.10.2 Method 2 . 118
3.10.3 Method 3 . 118
3.10.4 Method 4 . 118
3.10.5 Method 5 . 120
3.11 Tan δ measurement . 120
3.11.1 Method 1 – Tan δ test in relation to temperature . 120
3.11.2 Method 2 – Tan δ test in relation to temperature . 120
3.11.3 Method 3 – Tan δ test . 120
3.11.4 Method 4 – Loss factor measurement as a function of temperature . 121
3.12 Resistance of the insulating sheaths to weather conditions . 121
3.13 Adherence of screens at short circuit temperature . 123
3.14 Resistivity test for water blocking tape . 124
3.15 Moisture absorption test – Electric method . 124
3.16 Accelerated ageing test in relation to watertreeing . 125
3.17 Conductor short-circuit test . 126
3.18 Screen short-circuit test. 127
3.19 Earth Fault Short Circuit Test (Spike Test) . 127
4 Fire performance tests. 127
4.1 Flame propagation tests . 127
4.1.1 Flame propagation test – Method 1 . 127
4.1.2 Flame propagation test – Method 2 . 128
4.1.3 Flame propagation test – Method 3 . 149
4.1.4 Flame propagation test – Method 4 . 151
4.1.5 (Spare) . 153
4.1.6 (Spare) . 153
4.2 Smoke emission tests . 153
4.2.1 Smoke emission test – Method 1 . 153
4.2.2 Smoke emission test – Method 2 . 154
4.2.3 (Spare) . 156
4.2.4 (Spare) . 156
4.2.5 Smoke emission test – Method 5 . 156
4.3 Corrosive gas emission tests . 157
4.3.1 Corrosive gas emission test – Method 1 . 157
4.4 Toxic gas emission tests . 163
4.4.1 Toxic gas emission test – Method 1 . 163
4.4.2 (Spare) . 170
4.5 (Spare) . 170
4.6 (Spare) . 170
5 Long term tests . 170
5.1 Thermal endurance tests . 170
5.1.1 Thermal endurance test – Method 1 . 170
5.1.2 Thermal endurance test – Method 2 . 175
5.1.3 Thermal endurance test – Method 3 . 176
5.1.4 Thermal endurance test – Method 4 . 176
5.1.5 Thermal endurance test – Method 5 . 176

– 7 – HD 605 S2:2008
5.1.6 Thermal endurance test – Method 6 . 176
5.1.7 Thermal endurance test – Method 7 . 177
5.2 Pulling lubricant immersion test. 178
5.3 Long term water immersion test . 178
5.3.1 Method 1 . 178
5.3.2 Method 2 . 179
5.4 Long term voltage test . 179
5.4.1 Method 1 – Long duration test with thermal cycles . 179
5.4.2 Method 2 – Long term heat-cycling test . 180
5.4.3 Method 3 – Long term qualification test . 180
5.4.4 Method 4 – Long term qualification test . 180
5.4.5 Method 5 – Electrical long term test . 180
5.4.6 Method 6 – Long duration test . 181
5.4.7 Method 7 – Accelerated ageing test . 181
5.4.8 Method 8 – Test for resistance to water. 181
5.4.9 Method 9 – Long term qualification test . 181
5.4.10 Method 10 – Long term test . 181
5.4.11 Method 11 – Long term qualification test . 181
5.4.12 Method 12 – Long term qualification test . 181
5.4.13 Method 13 – Long term test for resistance to water and electrochemical treeing . 182
5.4.14 Method 14 – Long-term qualification test for water tree resistance and chemical
stability . 182
5.4.15 Harmonised long duration test . 182
5.5 Radial watertightness test and corrosion resistance test of metallic screen . 185
5.6 Insulation water resistance test . 185
Annex A (normative) Normative references . 187
Annex B (normative) Rounding of numbers . 189

1 General
1.1 Scope
This HD collates and specifies the test methods to be used for testing polymeric insulated and sheathed electric
cables, of rated voltage up to and including 20,8/36 kV, intended for public distribution systems, and for use in
power generating plants and sub-stations.
Test methods in this HD are additional to those already harmonised, e.g. EN 60332-1 series and EN 60811
series, and are used for testing cable types specified in HD 603, HD 604, HD 620, HD 622, HD 626 and HD 627.
In each case, these HDs give complementary information needed for the practical application to each specific
type. Therefore the present HD as such is not sufficient for carrying out and evaluating the tests on electric
cables.
Full test conditions (e.g. temperatures, durations) and/or test requirements are not specified in this HD. Such
data needed to carry out the tests is given in the particular sections.
NOTE The words 'particular section' refer throughout to the section of HD 603 or HD 604, or other HD to which HD 605 applies, in which a
particular cable type is specified.
1.2 Applicable tests
Tests applicable to each type of cable are given in the particular section, which may also state the sequence, the
frequency of test, and the possibility of repeating failed tests.
1.3 Classification of tests
The classification of tests is given in Parts 1 of HD 603, HD 604, HD 620, HD 622, HD 626 and HD 627.
1.4 Sampling
The size and number of samples are given either in this HD or in the particular HDs.
If a marking is indented in the insulation or sheath surface, the samples used for the tests shall be taken so as to
include such markings.
For multicore cables, except for the test specified in 2.1.1, not more than three cores (of different colours, if
available) shall be tested unless otherwise specified.
1.5 Test conditions
1.5.1 Ambient temperature
Unless otherwise specified in the details for the particular test, tests shall be made at an ambient temperature of
(20 ± 15) °C.
1.5.2 Tolerance on temperature values
Unless otherwise specified in the particular specification, the tolerance on temperature values quoted in the test
methods are the following:
– 9 – HD 605 S2:2008
Table 1.5.2 – Tolerance on temperature values
Specified temperature, t Tolerance
°C K
-40 ≤ t ≤ 0   ± 2
0 < t ≤ 50 according to relevant clause
50 < t ≤ 150 ± 2
t > 150 ± 3
1.5.3 Frequency and waveform of power-frequency test voltages
Unless otherwise specified the test voltage shall be in the range 49 Hz to 61 Hz of approximately sine-wave
form, the peak ratio value/r.m.s. value being equal to √2 with a tolerance of ± 7 %. The values given are r.m.s.
1.5.4 Pre-conditioning
Unless otherwise stated the tests shall be carried out not less than 16 h after the extrusion or cross-linking,
if any, of the insulating or sheathing compounds.
2 Non-electrical tests
2.1 Dimensional measurements
2.1.1 Measurement of insulation thickness
2.1.1.1 Procedure
The thickness of insulation shall be measured in accordance with EN 60811-1-1, 8.1. Unless otherwise specified
one sample of cable shall be taken and measurement made at three places.
Compliance shall be checked on each core of cables having up to five cores, and on the number of cores stated
in the individual specification for cables with more than five cores.
If withdrawal of the conductor is difficult, it shall be stretched in a tensile machine or the piece of core shall be
immersed in an appropriate liquid until the insulation becomes loose.
2.1.1.2 Evaluation of results
Unless otherwise specified the mean of the 18 values (expressed in millimetres) obtained from the three pieces
of insulation from each core shall be calculated to two decimal places and rounded off as given below, and this
shall be taken as the mean value of the thickness of insulation.
If in the calculation the second decimal figure is 5 or more, the first decimal figure shall be raised to the next
number thus, for example, 1,74 shall be rounded off to 1,7 and 1,75 to 1,8.
The lowest of all values obtained shall be taken as the minimum thickness of insulation at any place.
2.1.2 Measurement of non-metallic sheath thickness
2.1.2.1 Procedure
The thickness of sheath shall be measured in accordance with EN 60811-1-1, 8.2. Unless otherwise specified,
one sample of cable shall be taken and measurement made at three places.

2.1.2.2 Evaluation of results
The mean of all the values (expressed in millimetres) obtained from the three pieces of sheath shall be
calculated to two decimal places and rounded off as given below, and this shall be taken as the mean value of
the thickness of the sheath.
If in the calculation the second decimal figure is 5 or more, the first decimal figure shall be raised to the next
number, thus, for example, 1,74 shall be rounded off to 1,7 and 1,75 to 1,8.
The lowest of all values obtained shall be taken as the minimum thickness of sheath at any place.
2.1.3 Measurement of cable dimensions
2.1.3.1 Measurement of overall dimensions
Unless otherwise specified the three samples taken in accordance with this HD, 2.1.1 or 2.1.2 shall be used.
The measurement of the overall diameter of any circular cable and of the overall dimensions of flat cables with a
major dimension not exceeding 15 mm shall be carried out in accordance with EN 60811-1-1, 8.3.
For the measurement of flat cables with a major dimension exceeding 15 mm, a micrometer, a profile projector
or similar equipment shall be used.
The mean of the values obtained shall be taken as the mean overall dimensions.
2.1.3.2 Measurement of ovality
For checking the ovality of circular sheathed cables, two measurements shall be made at the same cross-
section of the cable, covering the maximum and minimum values.
2.1.4 Measurement of wires, strips and tapes
2.1.4.1 Conductor wires
Measurement of the diameter of conductor wires (class 5 conductors).
(a) Sampling
Take at random either 10 % of the total number of wires, rounded upwards, or 10 wires, whichever is the lowest,
from one core of each length of cable selected for the test.
(b) Method
Determine the diameter of each wire with a micrometer by taking a measurement in three positions, approx.
300 mm far away from each other. The readings shall be made to two decimal places. Take the average of the
three measurements to be the wire diameter.
2.1.4.2 Wires and tapes for concentric conductor or screen
(a) Sampling
A sample of about 500 mm length is taken from the test piece and straightened by means of a non-damaging
tool. After that it is cleaned.

– 11 – HD 605 S2:2008
(b) Procedure
For wires and tapes the diameter or the thickness is measured with an screw type micrometer or a dial gauge
with a measuring element with flat measurement planes with a diameter 4 mm to 8 mm. Measurements shall be
made at three points which are uniformly spread along the sample.
(c) Expression of results
The diameter or the thickness is the mean value obtained from the three measurements. The test is considered
to be fulfilled if the mean value does not fall below the minimum value prescribed in the particular specification.
2.1.4.3 Wires, strips and tapes for armour
(a) Round wires
Take at random 10 wires or 10 % of the total number of wires, whichever is the smaller, from a sample of the
completed cable.
Determine the diameter of each wire of this sampling by taking two measurements at right angles to each other
using a micrometer with flat noses to an accuracy of ± 0,01 mm.
Take the average value as the wire diameter.
(b) Flat wires or strips
Take at random 10 flat wires or strips or 10 % of the total number of flat wires or strips, whichever is the smaller,
from a sample of the completed cable.
Determine the thickness and width of each flat wire of this sampling by using either a micrometer with flat noses
to an accuracy of ± 0,01 mm or a vernier calliper with flat noses to an accuracy of ± 0,02 mm.
Take the average value as the wire thickness and wire width.
(c) Metallic tapes thickness
Take and straighten a sample of each armour tape, remove the non-metallic coating if any, and determine the
tape thickness at six different places.
The measurement shall be made with either a micrometer or a vernier calliper, both with two flat noses of
approximately 5 mm in diameter, to a respective accuracy of ± 0,01 mm or ± 0,02 mm. For tapes up to 40 mm in
width the thickness shall be measured at the centre of the width. For wider tapes the measurements shall be
made 20 mm from each edge of the tape and the average of the results taken as the thickness.
Take the smallest value to be compared with the specified thickness with a tolerance given in the particular
specification.
2.1.5 Measurement of thickness of metallic sheath
The thickness of lead sheaths shall be determined by one of the following methods, at the discretion of the
manufacturer. (Methods of measuring thickness of other types of metallic sheath are under consideration.)
(a) Strip method
The measurement shall be made on a test piece of sheath about 50 mm in length removed from the finished
cable length. The test piece shall be taken a sufficient distance from the cable end to allow a proper
measurement to be made.
The piece shall be slit longitudinally and carefully flattened. After cleaning the test piece, a number of
measurements shall be taken along the circumference of the sheath and not less than 10 mm away from the
edge of the flattened piece to ensure that the minimum thickness is measured. The measurement shall be made
with a micrometer with plane faces of 2 mm to 8 mm diameter and an accuracy of ± 0,01 mm.
(b) Ring method
The measurements shall be made on a ring of the sheath carefully cut from the sample. The thickness shall be
determined at a sufficient number of points around the circumference of the ring to ensure that the minimum
thickness is measured.
The measurements shall be made with a micrometer having either one flat nose and one ball nose, or one flat
nose and a flat rectangular nose 0,8 mm wide and 2,4 mm long. The ball nose or the flat rectangular nose shall
be applied to the inside of the ring. The accuracy of the micrometer shall be ± 0,01 mm.
2.1.6 Check of application of screen or armour tapes, or wires
2.1.6.1 Method 1
Take a cable sample 300 mm long, at not less than 150 mm from the end of a factory length. Measure the gap
between adjacent edges of the tape(s), and also the tape width. Measurement is made at 4 positions along the
sample, with an accuracy better than 0,5 mm.
2.1.6.2 Method 2
Remove two rings of the oversheath each 50 mm in length, cut at a distance of 5 D and 15 D, respectively,
(where D is the overall diameter) from one end of the cable length, so as to expose the metallic tapes or wires.
Make a visual examination of the exposed components and measure the largest gap between adjacent wires or
tapes. The measurement shall be made with an accuracy better than 0,5 mm and the result shall be given to
one decimal place.
2.1.7 Percentage coverage of a braided metallic layer
The percentage coverage "B" of the braiding shall be calculated by the following equation:
100d d
B = ( + - )
m n m n m n m n
1 1 2 2 1 1 2 2
q q
where
πDS
q =
2 2 2
+
π D S
D = mean diameter of braiding (= diameter under metallic layer + 2 d, mm);
d = nominal diameter of the wires of the braid, mm;
S = lay of the wires of the braiding, mm;
m = number of spindles in one direction;
m = number of spindles in the other direction;
n ; n = number of wires per spindle according to the direction.
1 2
– 13 – HD 605 S2:2008
2.1.8 Measurement of the gap between non-metallic tapes of taped bedding
See 2.1.6.1
2.1.9 Measurement of rubber layer thickness
2.1.9.1 Single rubber layer
The diameters over the copper conce
...