IEC 60079-0:1998/ISH1:2008

TC 31/Publication 60079-0 (1998), Third edition

and its amendment 1 (2000)/I-SH 01

ELECTRICAL APPARATUS FOR EXPLOSIVE

GAS ATMOSPHERES –
Part 0: General requirements
INTERPRETATION SHEET
This interpretation sheet has been prepared by committee 31: Equipment for explosive
atmospheres, of the IEC.
The text of this interpretation sheet is based on the following documents:
ISH Report on voting
31/766/ISH 31/777/RVD
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.
___________
Subclauses 23.4.7.3 and 23.4.7.4 of IEC 60079-0 (1998)
Following the discussions by the TC 31/WG 22 Task Group addressing the repeatability of the
thermal endurance to heat and thermal endurance to cold tests, it was proposed that a
tolerance be clarified for the test periods in Edition 6, 31/742/DC was issued and comments
received and resolved as 31/750A/INF.
These interpretations are made available for edition 3 of this standard due to the current use
of that standard by manufacturers, conformity assessment schemes and national bodies by
means of this “Interpretation Sheet” as follows:
Details of interpretation:
Interpretation of subclause 23.4.7.3 Thermal endurance to heat and 23.4.7.4 Thermal
endurance to cold of IEC 60079-0 (1998)
Question: As it is unreasonable to consider them to be the exact test time, are the time

frames for the 24 h, 336 h (2 weeks) or 672 h (4 weeks) tests considered to be the minimum
times? If so, what is the maximum time?
Interpretation: The 24 h, 336 h and 672 h values are considered the minimum number of
+2
hours for each of the tests. It is practical that the time periods should not extend beyond 24
+30 +30
h, 336 h, 672 h.
0 0
It is intended that this interpretation will be introduced in IEC 60079-0 Edition 6 and therefore
an Interpretation Sheet will not be required for this or future editions.

November 2008 ICS 29.260.20 French text overleaf

CE 31/Publication 60079-0 (1998), Troisième édition

et son amendement
...