“Draw a single-line diagram for a dairy farm with two 30 kWdc barn PV arrays, a 50 kW three-phase inverter, 480Y/277 V main distribution, revenue meter, and milking and refrigeration loads.”
図の背後にある意思決定を読み解く。
Two 30 kWdc arrays combine before the 1000 Vdc isolator.
A 50 kWac inverter converts the DC output for the 480Y/277 V board.
The PV feeder uses a 100 A, 25 kA breaker at the farm distribution.
The bidirectional meter sits between utility supply and the main board.
This arrangement suits a modest agricultural facility with a single interconnected service. A final design needs utility export approval and a load study for motor starting demand.
よくある質問
Why use 480Y/277 V?
It is a common three-phase service for commercial and agricultural motor and lighting loads.
What does the bidirectional meter record?
It measures energy imported from and exported to the utility for billing and interconnection purposes.
Can the PV run during a utility outage?
Not by itself; a grid-forming battery or approved backup system is needed for islanded operation.