innavent
Member
- Location
- Southern California
Apologies to those who have (i'm sure) continually answered these line-side tap questions. I've scoured the forums, but haven't found a situation exactly like mine, and have looked through 690.64 and still am unclear as to the requirements.
My situation. I have a client that i'm working on a permit set that has a split service with a 400A rated main. One split has a 150A breaker (to a 150A sub) and the other, a 200A breaker (to a 200A sub). He wants to backfeed 6 x SB3000HF's which are max output rated at 12.5A (x 1.25 x 6 = 93.75A) . The first question is that his original designer shows the inverters combining into a 200A AC panelboard. I think a 125A panel (MLO) should be ok -- correct? He's going to have visible fused utility disconnect. Secondly, he's concerned that a line-side tap is going to be an issue. I think it should be more than fine, but I cannot find guidance as to how many amps can actually be back-fed on a line-side tap.I understand the 20% rule, but what's (where can I find clearly) the capacity rule for a line-side tap?? Assuming we're OK capacity wise, where can I find guidance as to where the tap lives (i.e. tap lives in the AC disconnect??). This would assume there's room to tap as well??
Any help is greatly appreciated!!!
My situation. I have a client that i'm working on a permit set that has a split service with a 400A rated main. One split has a 150A breaker (to a 150A sub) and the other, a 200A breaker (to a 200A sub). He wants to backfeed 6 x SB3000HF's which are max output rated at 12.5A (x 1.25 x 6 = 93.75A) . The first question is that his original designer shows the inverters combining into a 200A AC panelboard. I think a 125A panel (MLO) should be ok -- correct? He's going to have visible fused utility disconnect. Secondly, he's concerned that a line-side tap is going to be an issue. I think it should be more than fine, but I cannot find guidance as to how many amps can actually be back-fed on a line-side tap.I understand the 20% rule, but what's (where can I find clearly) the capacity rule for a line-side tap?? Assuming we're OK capacity wise, where can I find guidance as to where the tap lives (i.e. tap lives in the AC disconnect??). This would assume there's room to tap as well??
Any help is greatly appreciated!!!