Got it, Thank you very much!A CT's rating typicially represents a ratio between how many amps on the measured conductor produces how many amps on the CT leads. So 600A is not exactly a max rating like for most other equipment. I'm sure that if you measured too many amps with that CT then you could overload the CT leads or the equipment they connect to. But as long as those things are accounted for it could measure more than the ratio rating. For example if the CT leads and equipment can safely handle 10A then a 600/5 rated CT I presume could safely measure 1200A.
I bet the 600A are cheaper than the next size up they would use, too.
As the current through a CT increases, at some point it will become saturated and no longer be able to register an increase, so yes. That point is somewhat more than its published rating.If the CT gets overloaded, will the meter record less than what you're actually using?? Just curious!
As mentioned by Mivey, the POCO likely doesn't believe your calculated NEC 220 load. You might come out to the service drop with 3 sets of conductors and they will meet you with 1 or 2 sets because they would have estimated the load to be less.One of our project has a system amperage of 960A and the POCO says that there will not be a problem to install a 600A CT for the metering cabinet, is this true?
Correct. POCO believes the calcs are per NEC but they realize the NEC is way too conservative. Recent example is a NEC load calc of over 240 amps. The reality is the load will probably never pass 160 amps at the maximum peak and will peak 100 amps or so routinely and average less than 30 amps. Real data from years of measuring similar loads.As mentioned by Mivey, the POCO likely doesn't believe your calculated NEC 220 load. You might come out to the service drop with 3 sets of conductors and they will meet you with 1 or 2 sets because they would have estimated the load to be less.
Good point.You utilize guys might want to keep in mind that this is in the PV forum. So depending on whether the OP already multiplied by 125%, the system likely will see a continuous current of 960A or at least 768 for several hours most days in the summer.