Roof top GFI Question

[Randy]

Greetings from Nebraska
Does Square D make a GFI breaker for roof top installations?
I have seen the ones from Zantrax and Outback which look fine yet I would
like to work with the QO line as much as possible.
I would be grateful for your help.
Thanks
Randy

 

[Randy]

Yessum. Gotta love google ;-).

http://ecatalog.squared.com/catalog/173/html/sections/06/17306011.html

DJ

AHH Thank you much. I was googling though this page but I was scared away by
the lack of or maybe I missed it DC ratings.
I have seen these in the stores but when I ask about their DC ratings they
tell me to go to Auto Zone.
So if I run the positive output from the solar panels into the QO 30 amp
box, ground as required then the output from the breaker to the solar input
positive on the charge controller, this should work ok?
I am running two 12 volt 30 watt panels in parallel so I should have a 5 to
8 amp fuse on the pos outputs in the combining box and have a lightning
protector installed too.
Thank you for your help as I know that despite all the flame wars and
wonderfull pesonalities we have here, I believe that everyone here cares
about each ones safety first and foremost.
Randy

 

[Bill Kaszeta / Photovoltaic Resources]

Yessum. Gotta love google ;-).

http://ecatalog.squared.com/catalog/173/html/sections/06/17306011.html

DJ

These are AC breakers and are not intended for use on DC circuits.
For PV systems on residental buildings you need a special
DC GFI that is Listed for use on PV systems. The requirements
are far different as they are not intended to protect from a shock
hazard.

Most grid-tie inverters include this function in the inverter and
a separate GFI is not needed.

Bill Kaszeta
Photovoltaic Resources Int'l
Tempe Arizona USA
[email protected]

 

[[email protected]]

Does Square D make a GFI breaker for roof top installations?

My Fronius inverter has GFCI built in. Does your controller not have that
protection built in, or are you looking for something closer to the
panels?

 

[Randy]

These are AC breakers and are not intended for use on DC circuits.
For PV systems on residental buildings you need a special
DC GFI that is Listed for use on PV systems. The requirements
are far different as they are not intended to protect from a shock
hazard.

Most grid-tie inverters include this function in the inverter and
a separate GFI is not needed.

Bill Kaszeta
Photovoltaic Resources Int'l
Tempe Arizona USA
[email protected]

Thanks for helping with my confusion here.
I will stick with Outback or Zantrax and do some homework with Lincoln
Electric System and see if they are ready for solar to touch their grid.
Electricity is cheap here but the last ice storm narrowly missed us so I am
looking at having quiet back up power with a grid intertie/battery backup
system.
Also this is a hobby for me but many people are watching with interest to
see how it works out.Am I just a nut or do I have something here.
I am looking at the Outback PS1-2500 power system at Alternate Energy Store,
and as many solar panels as I can talk my wife into (I haven't found
formulas or web pages to help me on that one.) I'll try to get as close to
2500 watts solar as I can.
Take care
Randy

 

[Bill Kaszeta / Photovoltaic Resources]

They do have Electrical Code DC ratings, though. But low voltage only,
not what you'd usually see in a grid tie array.


Yep, but I don't think this guy is talking about grid tie-ing 60watts
of PV ;-).

DJ

QO breakers do have DC ratings. The QO GFI that are referenced
by the link do not seem to have any DC ratings.
Bill Kaszeta
Photovoltaic Resources Int'l
Tempe Arizona USA
[email protected]

 

[Randy]

www.nmsu.edu/~tdi/pdf-resources/cc68.pdf

The DC rating on a QO breaker is voltage specific, not like a
dedicated DC breaker. It *would* be better to use a purpose built DC
breaker in your DC disconnect box, for instance. Actually, they're
often alot cheaper than QOs are...


In that case, you're probably ok. Check your local code, of course.
Actually, make sure that your wiring will take 30 amps (~#10) because
the breaker is supposed to be the weak link in the circuit.

DJ

Thanks DJ
I got a email from the fine folks at Alter Systems and I am considering
going with the Outback PS2 DC Breaker box with 175 amp inverter breaker and
the GFI breaker installed.
Our city code requires NEC 2003 so a nice trip to the library to read up and
the supervision of a master electrician friend upon install shoud be
helpful.
Also I have been reading a pdf from Alternate Energy about solar power and
what would meet code and what would not. That was an eye opener.
I am going with the *would* be better as inspectors in this area might feel
more comfortable with dedicated home solar power equipment.
Thanks for the advice on #10 as I have #12 outdoor uv rated.
I can always use the QO box in the garage, It was wired in 1924. Time for an
upgrade.
I will look into replacing the Pushmatic panel and several good condition
post and wire circuits in the house.
There have been about 4 upgrades to the wiring in the past but nobody went
to the bother of doing a full job.
Again thanks for everyones help, I will let you all know how it turns out.
Randy

 

[Randy]

QO breakers do have DC ratings. The QO GFI that are referenced
by the link do not seem to have any DC ratings.
Bill Kaszeta
Photovoltaic Resources Int'l
Tempe Arizona USA
[email protected]

My 60 watt panels could push any grid anywhere any time
Just kidding, I am in transition and learning stage, trying out what works
and what doesn't.
I am researching more so when I do make the big bucks decision on panels, I
won't regret my choices from power generation to safety.
Hopefully I will be able to grid inter-tie with enough power in the future.
Outback is possibly the company I will go with but I am still holding out
hope that Square D will come out with a easy to read page listing PV rated
equipment. I am finding DC ratings sprinkled around here and there on their
web site but I have to remember what Thomas Edison learned, the AC customers
are the most popular

 

[Randy]

Have you looked at the cost of grid tie inverters lately? ;-)


Apparently there is a document I found reference to on SD's page at
another location discussing Amperage re-rating: "For interrupting
ratings in dc applications, please refer to Square D data bulletin
0600DB0104, "DC-rated Circuit Breakers."

I couldn't find it, but, again, as I never use them... I just find
dedicated DC breakers are cheaper and easier to use.

DJ
Yes grid tie is very high and don't most rebate programs require grid tie?

That would drive up demand and price too.
Perhaps it may be better to go with a transfer switch or an inverter with
one built in, to run circuits say lighting for now and forget grid tie.
Also you have my attention with cheaper and easier.
What types are your favorite as I am trying to be safe but I shouldn't throw
money away needlessly..
Thanks

 

[[email protected]]

Another thing, too, is that you can set up non-grid tie, get a feel
for it, and switch to battery-based grid tie later if you start
feeling magnanimous with your power ;-).

A neighbor was building a house and thought they might go solar when they
found out how much a new power drop was going to cost. Then I pointed out
that the rebates and incentives on a grid tie coincidentally were the same
as the cost of getting the power drop.

You might need to get the grid-tie immediately to get the rebates and
incentives. Connecting later probably wouldn't qualify, as the equipment
needs to be "new", but I haven't investigated that qualifier.

That supposes, of course, that there are any grid tie rebates to be had.