Disconnectors for PV systems

Basically there are Different types of disconnectors for PV systems. Your commitment since 2006 prescribed by law and they are next to the Overvoltage protection an important component of a safe PV system. Disconnectors are used in PV systems to interrupt or close the circuit. They are used to disconnect the connection between the PV system and the internal and external power grid to ensure the safety of installers and maintenance technicians. Disconnectors make it possible to control the flow of electricity in the system and switch it off safely if necessary.

How disconnectors ensure safety in PV systems

Disconnectors are used to interrupt the circuit in PV systems. This is particularly important during Installation, Maintenance or repair of the system, as the individual Solar modules always carry electricity as soon as daylight falls on them. By interrupting the flow of electricity, installers and technicians can work safely on the system, without danger of an electric shock. In addition, disconnectors also enable the system to be switched off quickly in the event of an emergency or fault.

Disconnectors are also designed to provide a high level of electrical insulation. This means that they Safely interrupt the current flow without arcing or sparking. This minimizes the risk of fire or damage to the system. The use of disconnectors in PV systems is therefore essential to ensure the safety of the system.

Types of disconnectors used in PV systems

On the DC side of a PV system Disconnector at module level can be used. These load-break switches are installed externally near the module, regulate low to medium voltages and can disconnect individual modules or up to six modules from the line. So-called circuit-breakers can disconnect higher voltages. They are also installed on the outside and String level used. They are thus able to separate up to 20 solar modules from the system. Finally, they also serve the Inverter as disconnector on the DC side and the so-called fireman's switch, which can disconnect the direct current from the rest of the system as a safety component.

In general, the following applies No live DC cables into a lead closed building. If the inverters are installed inside the building, a Activation at string level indispensable. This requires the Installation of a fire department disconnector on the roof to de-energize the DC cables in the event of a fire. If the Inverter on the other hand on the roof or facade are installed, there is no need for disconnection at string or even module level. In this case, the live DC cables do not run through the interior of the building and, in the event of a fire, it is sufficient for the fire department to simply disconnect the building, as the inverters then switch off automatically and are de-energized after around five minutes due to the installed capacitors. The design of the strings and the Wiring of PV modules therefore also depends on the position of the inverters or rotary straighteners.

Additional disconnectors are also usually installed downstream of the inverters. These AC load-break switch or safety disconnectors in rooftop PV systems are usually located inside the commercial or industrial buildings in front of the control cabinets in which the entire PV system is installed. additionally by RCD is secured.

Factors to consider when making a selection

There are various factors to consider when selecting disconnectors for PV systems. The most important ones include Rated voltage and rated current of the system. It is important to choose disconnectors that are suitable for the specific voltage and current of the PV system. A disconnector that is not designed for the correct voltage or current can lead to Malfunctions or even to Damage to the system lead.

Another important factor when selecting disconnectors is the Protection class. PV systems are exposed to various environmental conditions, such as moisture or dust. It is therefore important to choose disconnectors with an appropriate degree of protection to ensure that they function reliably under the given conditions, as each individual plug connection basically represents a greater risk than a fixed cable.

Installation and maintenance of disconnectors for PV systems

The proper installation and maintenance of disconnectors is crucial for the Safety and efficiency of PV systems and is also used by the Insurances prescribed. During installation, the disconnectors must be installed in accordance with the applicable regulations and standards to ensure that they function properly. It is also important to test the disconnectors regularly. to maintain and check. After all Cables, connectors and the Electrical system of the PV modules They are exposed to the weather and are therefore subject to wear and tear, ageing, wind movements or animal browsing. Fire risk. An effective Fire protection system detects incipient fires at an early stage, the isolating switches specifically isolate these areas from the rest of the system, thus preventing consequential damage or operational failures.