I need to put 3 circuits of 20A (Enphase) into my 200A distribution panel, but my installer is saying I can only put in 40A due to 690.64 requirements.

Comments

Martha,690.64 is commonly known as the 120% rule. Basically, you can only feed an electrical panel (Solar and Utility Breaker combined) at 120% of its rating. In your case 200 * 1.2 = 240, hence the 40A - if your main breaker is 200A. One option for you might be to use a smaller main disconnect (from the utility). For example, if you could use a 180A main breaker, then you would have 60A of solar feed-in capacity.
You should check to see if you can do a supply side interconnection. Then you will not be limited to 40A. 
Other than that you can either replace the 200A panel with one that has a higher rating or as Stuart said, install a lower rated main breaker. The reason you are only allowed 40A is that you take 1.2 times the panel rating and subtract the main breaker rating. 
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11 years 2 months ago
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Greentech Renewables