TGRD

09:19 Dec 29, 2019 

I would also have found more context helpful, but sadly there is none that could remotely be of assistance. I am as puzzled as you are about how it can be a main switchboard if it is also a subordinate one. In the end I asked the client, but this particular one usually just notes the question and doesn't answer. But many thanks to you anyway, for taking the trouble to try to find a solution.

08:20 Dec 24, 2019 

Claude-Andrew highlights exactly my point:

TG normally indicates Tableau Général > Principal / Main / Overall switchboard — of which there is normally one upstream of all the other switchboards (if any), which then become secondary or sub-distribuion boards — often denoted as TD = Tableau Divisionnaire; but there appears (on the face of it) to be no technical logic in retaining the 'G' in this case. I suspect it may well be simply a slip of the pen — someone writing this without thinking about what the letters actually stand for! But only the (much) wider context might make this clear!

15:02 Dec 20, 2019 

In Schneider pdf http://ww2.ac-poitiers.fr/electrotechnique/sites/electrotech... we have:

1.1. Structure générale d'un réseau privé de distribution
Dans le cas général avec une alimentation en HTB, un réseau privé de distribution comporte
(voir fig. 1-1) :
- un poste de livraison HTB alimenté par une ou plusieurs sources, il est composé d'un ou
plusieurs jeux de barres et de disjoncteurs de protection

- une source de production interne

- un ou plusieurs transformateurs HTB / HTA

- un tableau principal HTA composé d'un ou plusieurs jeux de barres

- **un réseau de distribution interne en HTA alimentant des tableaux secondaires ou des
postes HTA / BT**

- des récepteurs HTA

- des transformateurs HTA / BT

- des tableaux et des réseaux basse tension

- des récepteurs basse tension.

Another possibility: RD = réseau domestique?

15:07 Dec 19, 2019 

@Asker,
More context would be more than helpful.

12:51 Dec 19, 2019 

Hard to be sure without a lot more context; I don't believe this is a "standard" abbreviation.
My hunch would be 'Réseau de Distribution' — except that technically, that seems an odd thing to have here!

There are also sub-dis boards referred to as 'divisionnaire' — but again, until we know what the 'R' stands for, it's hard to see how that could fit, since a 'Tableau Général' comes upstream of any 'tableau(x) divisionnaire(s)'.