What is this electric symbol found on an MCC-related electric single line diagram? It looks like a voltmeter with some sort of resistor but it would make more sense if it was an actuator I think.

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On some other places there is only the V symbol which probably is just a voltmeter:

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  • \$\begingroup\$ My first thought was 0-900V VOLTMETER but I'm not sure about the box on the LH side of it. \$\endgroup\$
    – jwh20
    Commented Sep 8, 2021 at 12:29
  • \$\begingroup\$ yes, I added a snipshot of a similar symbol without the box this time. \$\endgroup\$ Commented Sep 8, 2021 at 12:32
  • \$\begingroup\$ Can you go to the actual equipment and have a look? \$\endgroup\$ Commented Sep 8, 2021 at 12:34
  • 1
    \$\begingroup\$ @AndrewMorton that is sadly not an option \$\endgroup\$ Commented Sep 8, 2021 at 12:36
  • \$\begingroup\$ Since there is no capacity (kVA) rating on the transformer, I would suspect it is for metering. Are there any protective relays or other devices that would need a 0-110V voltage input signal? \$\endgroup\$
    – Theodore
    Commented Sep 8, 2021 at 12:41

1 Answer 1


This symbol enter image description here

  • does not seem to be adopted by modern standards for "Single-Line" Power grid Drawings.
    Rather now it looks a like a voltmeter symbol with an attachment. Delta generators might not be earthed, but Y neutral generators would be earthed. This might give some clue.

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