CIRCUTOR OT2-60D - Manual (Page 8)

DIELECTRIC STRENGTH TESTER FOR ISOLATING OILS OT2-60D --------- Page 8
Under demand:
4.9. TC/DE oil vessel - ASTM Specification D877
This Oil Vessel is used with the OT2-60D at 3000V/SEC for testing in accord with
ASTM Specification D877. This standard can be obtained from the American
Society For Testing and Materials.
4.10. TC/VDE oil vessel - ASTM Specification D1816
This Oil Vessel and motorized stirring assembly is used with the OT2-60D at
500v/SEC for testing in accord with ASTM Specification D1816. This standard
can be obtained from the American Society For Testing and Materials.
5. PREPARATION OF THE SAMPLE
5.1. Collection of the sample
It is very important to obtain results that adjust to the reality that you
strictly carry out the measures as it is mentioned next, otherwise, the
obtained results could be erroneous.
According to the IEC-156 standard it will be necessary to adopt the following
indications.
The oil sample will be taken in the place of the transformer, circuit breaker,
etc. where the oil is more contaminated, generally in the lowest zone of the
containers that contains it.
The amount of sample will be approximately three times superior to the
capacity of the test cell.
A topaz coloured glass bottle is the most appropriate container. The
transparent glass bottles can be used, but they must be protected of the direct
action of the light until the test is made. The plastic containers don’t have to be
attacked by the oil to test and if they are used, they cannot be reused.
In order to close the bottles, use a spiral cap, preferably of polyolefines or
polytetrafluorethylene.
The containers will be filled almost until the top, leaving approximately a 3% of
the volume of the container as free air space.
In case the container is reused, it must be cleaned (don’t forget the cap) by
means of washing with a suitable dissolvent to eliminate the rests of the last
sample. The containers will be washed finally with acetone, and the rests of
this dissolvent will be eliminated by means of hot air blown.
After the cleaning, the containers must be closed immediately and stay closed
until the moment of their use.