Detailed explanation of construction steps for roof distributed photovoltaic installation -Part 2

3.Tile sloping roof

The installation of tile sloping roofs is also a relatively dangerous construction site, so safety measures must be taken before construction. Details of tile roof construction:

1. Open expansion bolt holes on the cement roof, with the depth determined by the thickness of the roof;

2. Inject sealant into the expansion bolt hole;

3. Insert expansion bolts and fix the hooks onto the cement roof;

4. Apply sealant to the joint surface between the hook and the roof;

5. Fill the area around the hook with cement and do a good job of waterproofing, and restore the tiles.

4.Open ground

The installation of open ground supports should be determined based on the softness of the soil. There are generally several ways to fix the foundation:

1. Drilling and pouring;

2. Drilling pile;

3. Ground foundation construction;

4. Cement based blocks.

The brackets on the ground are similar to those on the roof, except that the ground is composed of multiple rows of components, while the roof is mainly laid in two or a single row.

Component installation

1. Components are grouped and connected according to inverters

The number of modules in each string depends on the inverter model, and there are several sets of positive and negative pins on the inverter, which requires us to pay attention to distinguishing the number of strings when connecting components.

2. Precautions for component installation

When installing components on a cement flat roof, if a single row of components is relatively long, they can be installed from the middle to both sides in sequence, so that the components can be installed more horizontally.

When installing components on a tile sloping roof, it is necessary to consider the connection method and string number of the components in advance. Before installing the next component, the pins of the two components should be connected first.

When installing components on the color steel tile surface, attention should also be paid to connecting the terminals of the two components before installing the next one.

3. Reliable grounding of the system

The system must be reliably grounded.

4. Cable Layout

The cable arrangement should be neat and centralized for easy maintenance. When threading or pulling cables, do not pull them forcefully to prevent damage to the cables.

System debugging

1. Check if the system is connected according to regulations

Check if each string of the system is connected in series, if the pins are securely plugged in, and if the grounding wire is reliably grounded.

2. Use a multimeter to determine the positive and negative poles

Connect the two probes of a multimeter to the two wires of each string, with the red probe indicating the positive pole. Afterwards, connect the positive and negative poles of each string to the corresponding positive and negative poles of the inverter.

Before closing the power supply, confirm again whether the voltage between each string group is normal (on sunny days, the voltage of each string group is equal to the sum of the voltages of each component).

Check if the live and neutral wires of the communication end are correctly connected to the live and neutral wires of the power supply. Close the circuit breakers at the DC and AC ends, turn on the inverter, and check the operation status of the inverter according to the inverter manual.

Engineering delivery

1. Provide a detailed explanation of the system usage method to the property owner

Introduce the operation method of the inverter to the owner, how to check the daily power generation, monthly power generation, and common conditions and operation methods such as fault display.

2. Fill in the owner’s receipt form

After the completion of the project, the contact person, contact phone number, address, project satisfaction, and basic information such as system kilowatt number and inverter model should be filled in by the construction party to the owner for later maintenance.