[RE-wrenches] Paralleling Multiple Inverter

William Miller william at millersolar.com
Sun Jan 22 10:19:30 PST 2012


Rich:

Here is the first consideration you might want to make:  You state a value 
of 100 Amps for this system, which I assume is the maximum AC output at 240 
VAC (25 Amps) times four inverters.  The value of 25 amps per inverter is 
irrelevant to your design, however.  You must take the 25 amps times 1.25 
(for continuous duty) which means your required breaker is 40 amps (unless 
you can find 35 amps breakers).  40 Amps is the relevant value.  40 times 4 
equals 160 amps.  Therefore, for purposes of 690.64(B) calculations, you 
have a 160 amp system.

Others on this list will no doubt provide advise on how to deal with that 
160 amps.

William Miller





At 04:53 AM 1/22/2012, you wrote:
>Content-Type: multipart/alternative;
>         boundary="----=_NextPart_000_003C_01CCD8DA.EAB9B150"
>Content-Language: en-us
>
>Good Morning Wrenches,
>I'm wondering if anyone has an advice on preferred methods and 
>component/panel recommendations for paralleling multiple inverters. The 
>proposed system will utilize 4 SMA6000 inverters (100 amps) and will be a 
>ground mounted system with inverters located outdoors in the cold frigid 
>temperatures of Vermont in a farmer's field so the panel where we complete 
>the parallel connections needs to be outdoor rated (although it will be 
>sheltered from the worst of the elements). It will be a standalone system 
>with a dedicated utility power drop/meter for the system. My understanding 
>of using a load center in this applications is that the 120% rule will 
>apply as it does in a typical installation per NEC690.64(B)(2)with the bus 
>amp rating for the load center based upon the inverter feed side as well 
>as the over current device on the utility side.
>Any input regarding preferred panels and configuration is appreciated.
>Thanks
>Rich
>




More information about the RE-wrenches mailing list