SINGLE LINE DIAGRAM

The Single Line Diagram is needed for construction and permitting.

STEP 1: CHOOSE SOLAR PANEL

Over the years we have installed solar panels made by SolarWorld, Sanyo, Mitsubishi, Sharp, LG Solar, Suniva, JA Solar, Hyundai, and Sunpower (from black market).. All of these makers have great quality control and good panels. In recent years our focus is on American made SolarWorld Solar panels. We do believe that the geometry of your space available will help us choose which panel.

STEP 2: Number of Panels and the System Size

In Southern California a Solarworld 275 watt solar panel will make approximately 1 kWh per day on an annualized basis. How many panels do you need to make your daily kWh usage? How many will fit?

STEP 3: What is Lowest Temperature?

What is the historical lowest annual temperature? Solar panels are tested at 25 degrees Celsius (77f) as this is considered their optimal operating temperature. Every 1 degree Celsius below 25 the voltage rating of the solar panel rises. The ratio is determined by the manufactures specification.

STEP 4: Which Inverter?

The Inverter choice is generally based on the overall system size. ABC Solar prefers inverters by SMA America for high quality and customer support. Other choices are between string and micro inverters.

STEP 5: String Size? # of Panels in Series.

Once the inverter has been chosen we determine the best string configuration for our system that meets the input characteristics. Voltage of the solar panel and temperature correction factor are considered.

STEP 6: Roof Type

The city building department will want to know the age, type and number of layers of your roof. Also the rafter size and distance on center. Structural details for wind and weight calculations as required.

STEP 7: What is the Hi-Temperature in Your Area?

Just like low-temperature, Hi-temperature makes the solar panel DC voltage lower. This is important for small string sizes that get close to the inverter minimum input needed for daily startup. The higher the temp the less performance.

STEP 8: Number of Wires in Each Conduit DC Side Two wires per string plus ground. Ex: 4 strings of 7 panels. 9 wires coming from the roof.

STEP 9: Number of Wires in Each Conduit AC Side Each string inverter will have 4 wires: 2 hot, one not, and ground.

STEP 10: Conduit Size

The conduit size is determined by number of wires, temperature, amperage and local code requirements.

STEP 11. Pick your Safety Disconnect Switches and PV Meter Once you have these steps done then you can create your single line diagram that is one part of the permit package set. Also, the utility company asks for the single line when the systems are big or they want to delay proceedings.