mrizon
Member
- Location
- Manteca, CA
Hello This is my first post on this forum. I am a Commercial PV Designer working toward my EIT and have been tasked with my first project. I have limited electrician experience (terminate cables and crimping, QC'd wire runs, combiner box wiring contest, etc..) through my experience as a Project Engineer at my previous position. Im not really working toward my Journyman's but I am always interested in improving conditions for my employees so that they may do their work more efficiently and easier (using Lean Six Sigma techniques) so I try to get in the field as much as possible and see what the ground troops do.
I am designing a 171kWDC PV system (located in Los Angeles) and have nailed down the equations and design all the way up to the 400A PV subpanel. My question is regarding backfeeding this subpanel. I have 672 modules (12 modules/string with 56 strings) feeding 2 inverters through Solectria 50kW and 100kW central inverters. (I did calculate excess voltage drop on the farthest string so I added another string of modules to help compensate the power loss due to this). Module specs are Voc:37.7
Isc: 8.9
Vmp: 31.1
Imp:8.4
My challenge is at the inverter output circuit. I output 240.57A and 144.34A (per datasheet) and if I connect these to the subpanel I would need 250A and 150A breaker in this panel. This does not seem right to me because I have only seen up to 80A breakers in these panels. Any help is appreciated, I feel like this is a simple answer but brainfarted.
I am designing a 171kWDC PV system (located in Los Angeles) and have nailed down the equations and design all the way up to the 400A PV subpanel. My question is regarding backfeeding this subpanel. I have 672 modules (12 modules/string with 56 strings) feeding 2 inverters through Solectria 50kW and 100kW central inverters. (I did calculate excess voltage drop on the farthest string so I added another string of modules to help compensate the power loss due to this). Module specs are Voc:37.7
Isc: 8.9
Vmp: 31.1
Imp:8.4
My challenge is at the inverter output circuit. I output 240.57A and 144.34A (per datasheet) and if I connect these to the subpanel I would need 250A and 150A breaker in this panel. This does not seem right to me because I have only seen up to 80A breakers in these panels. Any help is appreciated, I feel like this is a simple answer but brainfarted.