Direct acting indicating analogue electrical measuring instruments and their accessories - Part 3: Special requirements for wattmeters and varmeters

IEC 60051-3:2018 applies to direct acting indicating wattmeters and varmeters having an analogue display.

IEC 60051-3:2018 also applies to:

？？？ ？non-interchangeable accessories (as defined in 3.1.23 of IEC 60051-1:2016) used with wattmeters and varmeters;

？？？ ？a combination of the instruments and the accessories provided that the adjustments have been made for the combination;

？？？ ？direct acting indicating electrical measuring instruments whose scale marks do not correspond directly to their electrical input quantity, provided that the relationship between them is known;

？？？ ？instruments and accessories having electronic devices in their measuring and/or auxiliary circuits.

IEC 60051-3:2018 does not apply to:

？？？ ？special purpose instruments which are covered by their own IEC standards;

？？？ ？special purpose devices which are covered by their own IEC standards when they are used as accessories.

IEC 60051-3:2018 cancels and replaces the fourth edition published in 1984 and Amendment 1:1994. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous edition:

a)？？ ？updating of content in line