3-wire meter help

[starfury1]

Re: 3-wire meter help

The physical aspect, from what I understand is going to make it hard to be hooked up
I also think he is working with one Active only (I think, from what he said above).

Ok if the situation is as follows (electrically speaking) Pentium

IF one circuit say, the
20A circuit is off Red + A Active
and the other
15A circuit is off Black - B Active

Then yeah no worries you will have 240 Volts between the 2 Actives
So you can use the 240V 3 wire setup

Your only problem is then is how you physically put the meter between the 2 circuits

The only way to be sure of that is to measure both Actives of the new lines with a meter, if you got 240 Volts (Active to Active) then your OK for the 3 wire hook up
(or go chase the circuits in the box)

This is of course provided you actually have 2 Actives and a Neutral coming into your main electricity Box and that whoever hooks up the circuits does it that way, 1 circuit off each of the Actives

I believe there are single 110V volt systems, were you don't get the 240 (220) volt option.
(older setups from what I understand)

I dont know what rules and regs you have for what goes off what active...if any in that regard.

Remember I am working from some assumptions here in regard to the meter and I dont know for sure how correct they are.

Anyway thats my thoughts on it from what I can fathom of US system and the meter.

Lets us know how you go

Cheers

[starfury1]

Re: 3-wire meter help

You know there is one other thing that hasn't been mentioned here
The USA is now using Earth leakage and Arc breakers
What are the implications with that?

it just crossed my mind

[pentium]

Re: 3-wire meter help

I have never heard of earth leakage(GFCI?) or arc breakers.

This is of course provided you actually have 2 Actives and a Neutral coming into your main electricity Box

All homes in thy city that connect to the pole MUST have two actives (+120, -120) and a neutral. All homes must also have a single common neutral bus unless otherwise stated in our electrical code.

You also make a good point in mentioning that the two circuits must not both be on one of the two actives (won't make 240v).
That will be the fun part. I will have to track down which side the currently installed 15A breaker is on and install the 20A on the opposite side. At least it will be an excuse to sync all the alarm clocks.

This is the connection I last sent, and yes the power on both circuits will be measured correctly so long as the voltage coil is connected to 240V as per my diagram and yours of the meter.

You mean the diagram you posted a page back and halfway up the page?
I'm having trouble adapting that diagram to the way my meter looks. Use my sketch, make it smaller if you want and draw in the proper wiring coming in and out of the meter. I can work with something like that and note if that clip is to be open or closed.

Neutral is external, the return for each split, neutral current is minimised by having each split current close to equal.

So the neutral wire does not even enter the meter? Just indicate where the neutral goes in that sketch.

[starfury1]

Re: 3-wire meter help

Yeah thats what I am talking about

I know they do bring there own sets of issues with them, even thou they are there for protection of life and property.


As I said this is really the Provence of Licensed Electricians.

Its "strictly" hands off were I live.

[pentium]

Re: 3-wire meter help

Where we live, a GFCI is usually used around swimming pools and in bathrooms. When it comes to the rest of the house people use GFCI breakers.
I would use them but out square D panel is too old to fit them. In it's place is a ground fault alarm.

[davmax]

Re: 3-wire meter help

Both diagrams of 25th follow your meter diagram looking at the four terminals. The only guess I made was what the switch did. As I said in that post both connection diagrams are essentially the same and as intended by the manufacturer (switch excepted).
The load always connects across the two right terminals.
In the 240V case it is a single load at that voltage with no centre connection to neutral.
In the 120V case the load is split into two (like a centre tapped load) each half is returned to neutral as shown in the lower diagram. So two seperate 120V loads can be accomodated.
It is possible to mix loads. A 240V load directly connected to the two terminals and two 120V loads one to each terminal and returned to neutral. The meter will correctly measure such a mix.

Always the voltage coils must be connected to 240V connected across the two left terminals.

[pentium]

Re: 3-wire meter help

Wonderful!
I should be able to take care of things from here.
I'll tell you all how it works out.

[pentium]

Re: 3-wire meter help

It worked!

I followed the instructions and wired everything up and low and behold it works and it's metering both circuits.
Thanks guys.

[davmax]

Re: 3-wire meter help

Great. Congratulations. No electric shocks !!!!!!

[pentium]

Re: 3-wire meter help

Yep, I'm still alive and it's already giving an accurate reading.