ADLER photovoltaic fuses
Fuses, fuse holders and components for photovoltaic systems
In high voltage DC circuits such as photovoltaic systems, a protection fuse with the correct voltage and application characteristics must be used.
In PV systems, the current can easily exceed the operating current and reach a level that can cause overheating and damage. The fuses in this case behave like switches, if too high a current passes through them the internal filament overheats and melts, breaking the circuit.
To ensure the best possible protection for the system and for the people working on the equipment, fuses are always applied to both poles, positive and negative. In this way, the fuses will isolate the string of the plant concerned, allowing the photovoltaic system to continue generating electricity.
Characteristics of the fuses used in photovoltaic panels
Photovoltaic fuses need a low minimum current, this is the main difference between photovoltaic fuses and all the others.
Adler, our production partner for the photovoltaic sector, produces various solutions:
Fuse PV
in the classic cylindrical version, to be used in combination with the appropriate fuse holders, and in the version with perforated metal fins for screw fixing directly onto the plate. Suitable for the protection of the strings of panels in photovoltaic systems thanks to a high robustness due to the particular photovoltaic application.
Fuse PV NH also called knife, they are available in various versions with voltages up to 1500V and 400A. This model is particularly suitable for the protection of the components of a photovoltaic system.
Fuse-holders PV they are designed for all rated currents up to 30A at 1500V, providing the most compact and effective solution to protect 1500V circuits and equipment in photovoltaic applications. Switch disconnectors and circuit breakers complete the range.
Sizing of fuses for photovoltaic systems
A photovoltaic system can be composed of one or more strings connected together in parallel to provide more current and therefore more power.
To calculate the correct fuse for a photovoltaic system, some parameters must be taken into account:
- Number of strings in parallel (N)
- Number of connected solar panel modules (M)
- Room temperature
- Short circuit current of the string Isc
- Open circuit voltage Uoc stc
To determine the fuse voltage the formula is Un > 1.2 x M x (Uoc stc)
While to determine the rated current it is In> Isc / (Kt x Kc x Kg)
- Kt = temperature correction factor of the fuse (see curve)
- Kc = derating factor of the fuse for current variation.
- Kg = grouping factor (see table)
These rules do not apply to systems that have fewer than three strings, in this case fuses are unnecessary as they do not generate enough current to cause damage to conductors or equipment.
For more information contact our product specialists
Previous news 
Contact us for more information
