my diy pv set-up

[jwxr7]

Originally Posted by Daox

Doesn't look too bad, but what happened on Wednesday?

If Wednesday looks bad, look at the first thursday . They were cruddy dark days.

[Xringer]

Originally Posted by jwxr7

It's grid tied. The grid is the load.

Okay. Are you using the EnPhase AC Interconnect cable?
If you are, is the Blue wire being used as Neutral?

I suggest you find out why there is no current flowing in the neutral line.
Logically that could indicate an open circuit from the inverter.

I'm not an electrician, but as a home owner, I've wired up a 230V
outlet in my own home (it passed inspection) and frankly,
I'm a little worried that something is amiss with your hookup..



I've also built some 230 to 115 splitter cords for use with 230v
gas generators. They use the neutral line, just like the one that came
with my gas generator.

230 in, and two 115 sockets.. If no current was flowing in the neutral, they
wouldn't be working..

[jwxr7]

Rich,

Imagine a set of identical 120v ac loads, each connected from a different hot wire to the neutral of a 240v ac circuit. This is a balanced condition right? If you have a balanced load on a 240v ac circuit, how much current flows in the neutral?

You need to look at the grid as a simplified and balanced load on a grid tied inverter. A grid connected 240v ac inverter should not have current flowing in the neutral. If there is current, then something is wrong.

I'm not sure how Enphase has the neutral connected internally (just for communication?), but the grid tied inverters we are developing at work don't use the neutral. We don't want any neutral currents flowing.

[Xringer]

I see what you mean. Using a balanced load does the trick.


The Parallel load on the top rail perfectly matches the load on the bottom the load on the bottom rail.
So, the two rail loads, both being of the same resistance, act as a voltage divider across the 240, with a perfect 120v on each rail.
Causing zero current flow in the Neutral..

In my imperfect world, my wife is going to turn off one (or more) of those 100 watt lamps.

That would increase the resistance of the bottom rail, upsetting the balance.
Then there is going to be flow in the neutral.. Right??

----

Humm, If the guys who designed the mini-inverter added a voltage level control on each rail.
And then, used a current sensor in each hot line, to sense any imbalance in current flow.?.
They would be able to compensate for the imbalance by boosting the voltage on one rail,
until there was no more current on Neutral!

Hey! Perhaps that's how they are able to dump the full 200W onto an unbalanced grid!!

[Bob McGovern]

Originally Posted by jwxr7

You need to look at the grid as a simplified and balanced load on a grid tied inverter. A grid connected 240v ac inverter should not have current flowing in the neutral. If there is current, then something is wrong.

Correct. Four-wire 240 (hot-hot-N-ground), generally seen on (newer) clothes driers or ranges, employs only the two hot wires for the 240V loads. The neutral wire is used with either of the hot lines for 120V applications, such as the oven's displays, lights, and timers. I could imagine an inverter which worked that way. Then there would be some current in the N.

[groar]

Originally Posted by jwxr7

If Wednesday looks bad, look at the first thursday . They were cruddy dark days.

Panels need some amount of power to produce, the inverter needs some amount of power to produce (mine needs more than 100V per string), the meter needs some amount of power to measure (mine needs more than 25W (*) ).

(*) Under 100W displayed by my inverter, the meter is under, while it's over when the inverter displays more than 300W. Since the connection to the grid, the (selling) meter is 8% faster than the inverter

If clouds can mask, this morning the fog wasn't preventing luminosity as much as the freezing of yesterday.

Denis.

[jwxr7]

I calculated the last 30 days production, starting feb 1st 2009.

My solar array produced 22.38Kwhrs during this time.

The spring angle change is overdue. I hoped to do it a couple weeks ago when my brothers were over, but it was very windy, so we decided against it.

[MetroMPG]

Yay, 22.38 kWh ... that's just about enough energy to heat my uninsulated apartment for 24h when it's about -8C out.

Will your Spring angle change be "ahead" of today's optimal setting, so it reaches optimal again half way between now and your next planned change?

[Daox]

I'm very curious as to what % of your total usage is generated. I realize its likely very small, but I'm still quite interested.

[jwxr7]

Will your Spring angle change be "ahead" of today's optimal setting, so it reaches optimal again half way between now and your next planned change?

Yeah, I believe so. I've been following advice from this site on the angling of my panels. Optimum Orientation of Solar Panels

When I get my latest electric bill, I plan to compare useage to production. If I were watching my utility meter better I wouldn't have to wait for the bill .