However, when the initial verification takes place in the manufacturer's workshops, the tests may be carried out with the cover removed as long as it has been previously accepted as having practically no effect on the
performance of the meter.
Nevertheless, when dielectric properties are checked, the meter cover shall be fitted. A
fter the dielectric strength test has been satisfactorily carried out, but before any other test, the meters shall be supplied with electricity f
...[+++]or at least half an hour at the reference voltage and with a current of about 0.1 Ib, at unity power factor.