PM/ IS 335/ 1/ December 2018
PRODUCT MANUAL FOR
NEW INSULATING OILS
ACCORDING TO IS 335:2018
This Product Manual shall be used as reference material by all Regional/Branch Offices &
licensees to ensure coherence of practice and transparency in operation of certification under
Scheme-I of Bureau of Indian Standards (Conformity Assessment) Regulations, 2018 for
various products. The document may also be used by prospective applicants desirous of
obtaining BIS certification licence/certificate.
1. Product : IS 335:2018
Title : New Insulating Oils
No. of Amendments : Nil
2. Sampling Guidelines:
a) Raw material : __
Each Classification (as per clause 5.1 of IS 335:2018) of
b) Grouping guidelines :
New Insulating Oil shall be tested for GoL and CSoL.
c) Sample Size : 10 litres of New Insulating Oil
3. List of Test Equipment : Please refer ANNEX – A
Scheme of Inspection
4. : Please refer ANNEX – B
and Testing
5. Possible tests in a day : Please refer ANNEX – C
6. Scope of the Licence :
“Licence is granted to use Standard Mark as per IS 335:2018 with the following scope:
Name of the product New Insulating Oils
Classification As per clause 5.1 of IS 335:2018
BUREAU OF INDIAN STANDARDS
Manak Bhawan, 9, Bahadur Shah Zafar Marg,
New Delhi – 110002
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PM/ IS 335/ 1/ November 2018
ANNEX A
List Of Test Equipment
Major test equipment required to test as per the Indian Standard
Sl. Tests Used in with
Test Equipment
No Clause reference
1 Hydrometer Cl. 6.16
2 Viscometer Cl. 6.1
3 Interfacial Tensiometer Cl. 6.8
4 Pensky Martens Flash Point Tester Cl. 6.15
5 Pour Point Test Apparatus Cl. 6.2
6 Corrosive Sulphur Test Oven along with copper strip Cl. 6.10
7 Tan Delta Apparatus with Test Cell Cl. 6.5
Oxidation Stability Test Apparatus, Burette with stand, Pipette,
8 Cl. 6.12
Measuring Cylinder
9 Karl Fischer Apparatus Cl. 6.3
10 Measuring Cylinder, Beakers Cl. 6.2
The above list is indicative only and may not be treated as exhaustive.
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PM/ IS 335/ 1/ December 2018
ANNEX B
Scheme Of Inspection And Testing
1. LABORATORY - A laboratory shall be maintained which shall be suitably equipped
(as per the requirement given in column 2 of Table 1) and staffed, where different tests given
in the specification shall be carried out in accordance with the methods given in the
specification.
1.1 The manufacturer shall prepare a calibration plan for the test equipment.
2. TEST RECORDS – The manufacturer shall maintain test records for the tests carried out
to establish conformity.
3. LABELLING AND MARKING – As per the requirements of IS 335:2018.
4.1 REPACKING OF NEW INSULATING OIL – If a firm is doing only re-packing of new
insulating oils at their premises, then each consignment of new insulating oil received shall be
accompanied by a certificate bearing the Standard Mark of the Bureau.
4.2 LEVELS OF CONTROL - The tests as indicated in column 1 of Table 1 and the levels
of control in column 3 of Table 1, shall be carried out on the whole production of the factory
which is covered by this plan and appropriate records maintained in accordance with
paragraph 2 above. In case a license is issued only for re-packing of new insulating oil, then
the tests as indicated in Table 2 of SIT and the levels of controls specified therein, shall be
applicable, instead of Table 1 of SIT.
5. CONTROL UNIT – For the purpose of Table 1 of this Scheme, each class of new insulating
oil produced in a day shall constitute a control unit.
6. REJECTIONS – Disposal of non-conforming product shall be done in such a way so as to
ensure that there is no violation of provisions of BIS Act, 2016.
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PM/ IS 335/1/December 2018
TABLE 1
(1) (2) (3)
Test Details Test equipment requirement Levels of Control
Cl. Requirement Test Methods R: required (or) S: Sub- No. of Frequency Remarks
Clause Reference contracting permitted Sample
6.1, Table 1, If the insulating oil fails in any
6.1 Viscosity IS 335 R 1 requirement, two more
Table 2
samples shall be drawn from
6.2, Table 1, the same control unit and
6.2 Pour Point IS 335 R 1
Table 2 Each control unit tested for those particular
6.3 Water Content 6.3, Table 2 IS 335 R 1 requirements and the control
unit shall be rejected if there is
6.4 Breakdown Voltage 6.4, Table 2 IS 335 R 1 any further failure. The
Once in three control unit so rejected may be
suitably re-processed and the
6.5 DDF at 90 ºC 6.5, Table 2 IS 335 S 1 months from each
defects rectified. Such
class of oil
re-processed control unit may
6.6 Appearance 6.6, Table 2 IS 335 R 1 be marked when tested again
in accordance with the
6.7 Acidity 6.7, Table 2 IS 335 R 1 Each control unit Scheme and found
Interfacial Tension conforming to the
6.8 6.8, Table 2 IS 335 R 1
(IFT) requirements of the
6.9 6.9, 7.1 Specification.
Sulphur Content IS 335 S 1
7.1 Table 2 Once in three
Corrosive Sulphur and months from each
6.10 Potentially Corrosive 6.10, Table 2 IS 335 S 1 class of oil
Sulphur
6.11 Additives 6.11, Table 2 IS 335 R 1 Each control unit
Once in six months
6.12 6.12, 7.1
Oxidation Stability IS 335 S 1 from each class of
7.1 Table 2
oil
Once in three
6.13 6.13, 7.3
Gassing Tendency IS 335 S 1 months from each
7.3 Table 2
class of oil
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PM/ IS 335/1/December 2018
TABLE 1
(1) (2) (3)
Test Details Test equipment requirement Levels of Control
Cl. Requirement Test Methods R: required (or) S: Sub- No. of Frequency Remarks
contracting permitted
Clause Reference Sample
6.14, 7.2 1 Once in six months If the insulating oil fails in any
6.14 Electrostatic Charging
Table 2 IS 335 S from each class of requirement, two more
7.2 Tendency (ECT)
oil samples shall be drawn from
the same control unit and
6.15 Flash Point 6.15, Table 2 IS 335 R 1 tested for those particular
Each control unit
6.16 Density 6.16, Table 2 IS 335 R 1 requirements and the control
unit shall be rejected if there is
Polycyclic Aromatics any further failure. The
6.17 6.17, Table 2 IS 335 S 1
(PCA) control unit so rejected may be
suitably re-processed and the
Polychlorinated
6.18 6.18, Table 2 IS 335 S 1 defects rectified. Such
Biphenyls (PCB)
re-processed control unit may
2-Furfural (2-FAL) and Once in six months be marked when tested again
6.19 Related Compounds 6.19, Table 2 IS 335 S 1 from each class of in accordance with the
Content oil Scheme and found
6.20 Particle Content 6.20, Table 2 IS 335 S 1 conforming to the
requirements of the
6.21 DBDS Content 6.21, Table 2 IS 335 S 1 Specification.
6.22 Stray Gassing of Oil 6.22 IS 335 S 1
Note- 1: Sub-contracting is permitted to a laboratory recognized by the Bureau or Government laboratories empanelled by the Bureau.
Note- 2: Levels of control given in column 3 are only recommendatory in nature. The manufacturer may define the control unit/batch/lot and submit his
own levels of control in column 3 with proper justification for approval by BO Head.
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PM/ IS 335/1/December 2018
TABLE 2
(FOR REPACKING UNIT)
(1) (2) (3)
Test Details Test equipment requirement Levels of Control
Cl. Requirement Test Methods R: required (or) S: Sub-contracting No. of Frequency Remarks
Clause Reference permitted Sample
6.1 Viscosity 6.1, Table 2 IS 335 R 1 If the insulating oil fails in any
6.2 Pour Point 6.2, Table 2 IS 335 R 1 requirement, two more
* samples shall be drawn from
6.3 Water Content 6.3, Table 2 IS 335 R 1
Breakdown
the same consignment and
6.4 6.4, Table 2 IS 335 R 1 tested for those particular
Voltage
Once in six months from requirements and the
6.5 DDF at 90 ºC 6.5, Table 2 IS 335 S 1 each class of oil received consignment shall be rejected
from each manufacturer if there is any further failure.
6.6 Appearance 6.6, Table 2 IS 335 R 1 The consignment so rejected
6.7 Acidity 6.7, Table 2 IS 335 R 1 may be returned to the supplier
*
Interfacial Tension for re-processing.
6.8 6.8, Table 2 IS 335 R 1
(IFT)
6.9 6.9, 7.1
Sulphur Content IS 335 S 1
7.1 Table 2 Once in six months from
Corrosive Sulphur each class of oil received
6.10 and Potentially 6.10, Table 2 IS 335 S 1 from each manufacturer
Corrosive Sulphur
6.11 Additives 6.11, Table 2 IS 335 R 1 *
6.12, 7.1 Once in a year from each
6.1 Table 2
Oxidation Stability IS 335 S 1 class of oil received from
7.1
each manufacturer
Once in six months from
6.1 6.13, 7.3
Gassing Tendency IS 335 S 1 each class of oil received
7.3 Table 2
from each manufacturer
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PM/ IS 335/1/December 2018
TABLE 2
(FOR REPACKING UNIT)
(1) (2) (3)
Test Details Test equipment requirement Levels of Control
Cl. Requirement Test Methods R: required (or) S: Sub-contracting No. of Frequency Remarks
permitted
Sample
Clause Reference
Electrostatic 6.14, 7.2 Once in a year from each If the insulating oil fails in any
6.14
Charging Tendency Table 2 IS 335 S 1 class of oil received from requirement, two more samples
7.2
(ECT) each manufacturer shall be drawn from the same
6.15 Flash Point 6.15, Table 2 IS 335 R 1 consignment and tested for
*
6.16 Density 6.16, Table 2 IS 335 R 1 those particular requirements
Polycyclic and the consignment shall be
6.17 6.17, Table 2 IS 335 S 1
Aromatics (PCA)
rejected if there is any further
Polychlorinated
6.18 6.18, Table 2 IS 335 S 1 failure. The consignment so
Biphenyls (PCB)
2-Furfural (2-FAL) rejected may be returned to the
and Related
Once in a year from each
6.19 6.19, Table 2 IS 335 S 1 supplier for re processing.
Compounds class of oil received from
Content each manufacturer
6.20 Particle Content 6.20, Table 2 IS 335 S 1
6.21 DBDS Content 6.21, Table 2 IS 335 S 1
6.22 Stray Gassing of Oil 6.22 IS 335 S 1
* From each class of New Insulating Oil produced in a day by each manufacturer, in each consignment received.
Note- 1: Sub-contracting is permitted to a laboratory recognized by the Bureau or Government laboratories empanelled by the Bureau.
Note- 2: Levels of control given in column 3 are only recommendatory in nature. The manufacturer may define the control unit/batch/lot and submit his
own levels of control in column 3 with proper justification for approval by BO Head.
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PM/ IS 335/1/December 2018
ANNEX C
Possible Tests in a day
(i) Appearance
(ii) Viscosity at 40 ºC
(iii) Viscosity at 0 ºC
(iv) Density at 20 ºC
(v) Flash Point
(vi) Interfacial Tension
(vii) Water content
(viii) Breakdown Voltage
(ix) Acidity
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