harvardbeans
New Member
- Joined
- Dec 2, 2022
- Messages
- 10
Hi, and thanks for reading. I'm beginning an off-grid mini split ac/heat install on a cabin in middle Tennessee. I have a construction/remodeling company and have an intermediate level of knowledge about AC power but am a beginner when it comes to solar and DC power. I want to install 9 blue sun 460w bifacial panels on a shed roof and run them to an EG4 6000ex-48HV. The first questions are about how to most effectively position and string the panels together. The roof has a gable in the middle and the pitch is roughly 4/12 or perhaps 3/12 so as the sun passes overhead, it will shine on one side of the roof until about noon and then the other side until sundown, but neither side is shaded, just not direct sunlight. Should I wire all 9 in series with 4 on one side of the gable and 5 on the other or will different amounts on sunlight on each half the array bog it down? If so should I put them all on the same side and collect more sunshine for half the day and less during the other half? I read somewhere that there is good reason to parallel two strings in series but I don't remember why.
The next question is about installing a DC breaker between the inverter and the array. The manual says the inverter's typical amperage is 27A and cautions to use a DC breaker between the inverter and array, but doesn't give any specs on the breaker. Should I use a 30A breaker? The panels are 50.8v each and the inverter's max VOC is 450. Every diagram I look at shows a DC isolator between the panels and inverter. It seems like a breaker serves the same purpose. Would installing both be redundant?
The inverter will be connected to and charge/draw power from two 30KWH battery banks, each with six 5KWH eg4 server rack batteries. Power going out from the inverter will be 240v to the mini split outdoor unit. The mini split will also be powered directly by a second pv array mounted above it on the house. I think all I need between the mini split and the inverter is an AC breaker and between the mini split and the array is either an isolator or a dc breaker.
As for battery to inverter cables, I have 1 gauge wires and I ordered an adjustable torque wrench to make sure all my connections are to spec.
Hopefully once these questions are cleared up (unless I'm not asking the right questions) I'lll be ready to begin the install. Thanks in advance for anyone willing to help out a newb.
The next question is about installing a DC breaker between the inverter and the array. The manual says the inverter's typical amperage is 27A and cautions to use a DC breaker between the inverter and array, but doesn't give any specs on the breaker. Should I use a 30A breaker? The panels are 50.8v each and the inverter's max VOC is 450. Every diagram I look at shows a DC isolator between the panels and inverter. It seems like a breaker serves the same purpose. Would installing both be redundant?
The inverter will be connected to and charge/draw power from two 30KWH battery banks, each with six 5KWH eg4 server rack batteries. Power going out from the inverter will be 240v to the mini split outdoor unit. The mini split will also be powered directly by a second pv array mounted above it on the house. I think all I need between the mini split and the inverter is an AC breaker and between the mini split and the array is either an isolator or a dc breaker.
As for battery to inverter cables, I have 1 gauge wires and I ordered an adjustable torque wrench to make sure all my connections are to spec.
Hopefully once these questions are cleared up (unless I'm not asking the right questions) I'lll be ready to begin the install. Thanks in advance for anyone willing to help out a newb.