In other words, given a socket box, does it matter which of line or load is connected one side or the other of the meter?

Regards
--Campagne

Sure does!

LINE is on top.
LOAD is on bottom.

The convention is Line on TOP, so for the safety of anyone working on the system, wire it this way.

Older (electro-mechanical) single phase electric meters would run backwards when installed upside down, so people would turn them upside down a few days each month to steal power.

But the power companies wised up, not only do the newer (electronic) meters not allow you to do this, many also send a tamper signal back to the utility.

If the utility suspects you are using power without paying for it, they will also monitor your line from a remote location.

Thanks a lot. I was not trying to be clever or devious. Here is what happened.

We are in the process of having the overhead service changed to an underground service.

I had laid the conduit from the transformer to the house but, before I could install the socket meter box, the utility got the cable through the conduit and left it dangling. I was to call them back for inspection and, if all was right, they would switch the meter from the overhead box to the underground box.

I got a socket meter box, Siemens Ringless Type Meter Socket 200A SUA S877 - PPZA, and installed it but while it gave the necessary torque amount, there was no indication of line or load and the knockouts were both at the bottom. From the look of things and from the fact that in the overhead days, the top contacts of the meter would have been for the line and the bottom contacts would have been for the load, I connected the wires accordingly---but left enough slack to switch if necessary and did not torque the lugs.

I kept on wiring: ground rod by the meter box , ground rod by entrance panel connected to the first since the entrance panel is 15 feet away from the meter, 4-wire feed from the entrance panel to the sub-panel, removed strap between the neutral and ground busses of the 100A sub-panel, etc worrying all the time about the socket meter box connections as I sure didn't want the utility company to get wrong ideas.

So, when I finally posted, I didn't want to prejudice things so as to be absolutely, totally sure.

Well, thanks to you, I am now absolutely, totally sure and will finish things up: torque the connections, bring a number of circuits close to the panels so that, when the utility comes and, if everything is OK by them, switches the meter, I can move a good part of the load from the overhead entrance panel to the two new panels in not too much time.

But I still have a question: can I leave the slack in the socket meter box since the wires are not springing against anything or should I trim the wires anyhow before I torque the lugs?

In any case, I would like to apologize for acting coy in my initial post and am very, very grateful for these replies.

Best regards
--Campagne

P.S. This is my second attempt at answering. Somehow, the first one evaporated.

You should be checking with your utility for their service entrance requirements.

See Illustration #13 found in this booklet:
http://www.cmpco.com/MediaLibrary/3/...s/handbook.pdf

You will see how they want meters wired.

Meter sockets are not labeled to give utility companies the choice of how they want their systems connected.

I do not know of any that would want Line on the bottom, but I am sure it may exist.

Given the very asymmetrical layout of the Siemens meter box, it is unlikely that any choice was intended. Thanks for the booklet and, indeed, illustration 13 settles the issue. (I went through the result of the booklet too. Ouch.) Still, I am going to bite the bullet and take your advice and email the utility engineer to "verify"with him (not ask).
Well, as far as I am concerned, this issue is closed---but should the engineer think otherwise, I will of course post.
Once again, thanks to all as it is good to deal with people who know what they are talking about.
Very grateful regards
--Campagne

There are also some regulations as to what side the line side of the conduit should be on. Sometimes they also require conduit body on the line side.