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#200363 03/29/11 02:46 PM
Joined: Sep 2003
Posts: 114
B
Member
I'm needing to find the Open Circuit Voltage and the Short Circuit Amps.

There are two strings going into the combiner box. Each string has 7 modules. I'm fairly certain I'm needing to open the combiner box and do the tests there for each string.

Finding the Open circuit Voltage is pretty simple: Positive to Negative with a DC tester. However the Short Circuit Amps is my concern.

How do I perform this test? I'm thinking I connect the positive and negative wires together then use an Ammeter.

Any advice would be appreciated.

Thanks!

Joined: Jul 2004
Posts: 9,672
Likes: 7
G
Member
I think the manufacture's data is the best source for peak output. Field testing is just using the array as a very expensive light meter. wink


Greg Fretwell
Joined: Sep 2003
Posts: 114
B
Member
The power company is asking for the Time of Day of the test. That leads me to believe they want a field test.

Thanks!

Joined: Oct 2000
Posts: 2,722
Broom Pusher and
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bwise;

Best suggestion is to verify with the Utility Service Engineer / Planner, as to what data is satisfactory for the SCA submittal; i.e. Manufacturer's Cut-Sheets, or Actual Field Test.
The Service Planner should tell you specifically where to obtain the Data (Mfg. or Field Test), along with submitting relevant ESR Pages to you, for reference.

Contact the Service Planner, and verify where the SCA Data is to be derived - Spec. Sheets, or Field.
If a Field Test is required (sounds unlikely, but....), then you will need to perform the Test as indicated in the ESR Manual (Electrical Service Requirements), as well as per the MFG. Specifications.

Typically, such a Test involves connecting the entire Array together (as would be for normal running conditions), "Bolt" the Output together via an adequately sized jumper, then measure the Current Flow through that Jumper - either via a Clamp-Type Ammeter, via a CT piped into a Multimeter, or via a Series-Type Ammeter (most likely a Shunted Approach).

Testing would be performed with the Sun at the most effective angle (time of day -vs- latitude).

Good luck.

-- Scott


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Joined: Oct 2000
Posts: 2,722
Broom Pusher and
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El-Bump'o!!!

Hey bwise;

Any News on this subject?

I am curious to the extent of these PV Installs, as my Designs will soon be including various types of Alternative Energy Systems.

-- Scott


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
Joined: Feb 2003
Posts: 939
F
Member
Bwise.,

I am not sure how this work out but one way you can find out is take a single panel and do the short circuit of that panel to see how much it will produce and I am aware the solar panels are not a infine source so it may get by with lower rating but the best answer is check with the manufacter of that solar panel they should able give you some infomation what you are looking for.

And also most larger solar panels I have see they will have sectional fuses as well { some will use circuit breaker as well as long they are rated for DC useage.}

I know one of the guys in the fourm is inspecting the large solar panel maybe he can give you some infomation if he do know about it.

Merci,
Marc


Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

Joined: Jul 2007
Posts: 1,335
S
Member
All that data should be right on the panel. Multiple panels system can be calculated based on ohms law. Not sure what the POCO is after


"Live Awesome!" - Kevin Carosa
Joined: Mar 2011
Posts: 98
V
Member
Originally Posted by bwise121
I'm needing to find the Open Circuit Voltage and the Short Circuit Amps.

There are two strings going into the combiner box. Each string has 7 modules. I'm fairly certain I'm needing to open the combiner box and do the tests there for each string.

Finding the Open circuit Voltage is pretty simple: Positive to Negative with a DC tester. However the Short Circuit Amps is my concern.

How do I perform this test? I'm thinking I connect the positive and negative wires together then use an Ammeter.

Any advice would be appreciated.

Thanks!


We've been using one of these with great success for about a year now.

http://www.solarbos.com/products.php?cat=28

Quick and easy, especially when we have to test 300-400 strings a day.



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