Electric arc protection system to prevent fires on photovoltaic systems

A protection useful for preventing fires and applicable for activities subject to the control of the Fire Brigade
Produced and marketed by FLASH INNOVATIONS SRL SB Benefit Company
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Functional to 96%
arc fault tests (passed 28 out of 29 tests) *
Immune to 100%
from injected disorders (passed 23 out of 23 tests) * 
test performed in 2018/2019 at Fraunhofer-ISE Freiburg, Germany

The solution

The solution ARCOSTOP is developed through a targeted risk analysis, applying electric arc detection equipment that does not modify the existing systems and mitigating the greater risk due to the presence of the photovoltaic system.

ARCOSTOP allows the opening of the direct current lines (string cables) ensuring the interruption of the DC arc. Alternatively, it is possible to interrupt the ongoing arc by unhooking the AC side of the inverter.


ARCOSTOP is an AFD photovoltaic arc detection system (ARC FAULT DETECTOR) consisting of a toroidal sensor and a detection card placed inside a container.

The solution ARCOSTOP allows you to anticipate the ignition of fire caused by electric arcs.

ARCOSTOP it is an innovative system for the protection of photovoltaic systems as a technical mitigation solution, also useful, where required, for obtaining the favorable opinion of the Fire Brigade.

Insurance bodies appreciate this solution and can apply better policies against fire risks on the roofs of buildings where PV panels are present.

The system ARCOSTOP it can be applied both in retrofit without modifications to the existing wiring (simply insert the strings into the DC side toroids), and for new photovoltaic systems.

Release and Signaling
Once the arc has been detected, the device very quickly switches the exchange contacts present on board the device which can be used to pilot the release of the circuit concerned. The second contact, however, for example, can be used to control an optical/acoustic signal, a fire detection control unit or a telephone dialer, etc...
CE marking
After passing the electromagnetic compatibility tests, it obtained the CE marking.
Complete with manual
Comes complete with user manual and installation sheet

Photovoltaic technology has evolved rapidly following the incentives available at the time and many systems today do not fully comply with the Fire Brigade Regulations and Circulars.

Fires in photovoltaic systems have intensified in recent times, drawing the attention of the Fire Brigade. (see Technical Report on Photovoltaic Fires of NIA Fire Investigation Unit Oct. 2015).

From the studies carried out to date, the fires are "in fact" mainly attributable to electric arcs also due to the deterioration of the insulators, exposed to atmospheric agents (terminals, cables, junction boxes, etc...), to poor maintenance, all contributing causes that lead to the possible onset of fires.

ARCOSTOP is to be considered capable of carrying out the main action of reducing the risk of fire starting and this also in application of Circular 04/05/2012 annex B to point 3/b. See Italian legislation currently in force.

How ARCOSTOP works

This device, in the presence of PV systems installed on and off the roof, is a useful protection for preventing fires and therefore also applicable for all activities subject to the control of the Fire Brigade.

ARCOSTOP allows you to anticipate the start of fire caused by electric arcs
It is a modular device for DIN rail; it, through reading acquired from the associated toroid, is able to detect the generation of electric arcs.
Timely intervention
It is a device that intervenes promptly on the controlled circuit by sending a command capable of interrupting the onset of the electric arc.
It can detect electric arcs that occur both upstream of the sensor and in the PV system components located downstream
as well as monitoring all DC pipelines of the system itself.
Interruption of the electric arc
It allows the opening of the DC lines ensuring the interruption of the electric arc.
It is known that if an electric arc persists, it can start fires.
Provides notification of the event.
Following electromagnetic compatibility tests, it obtained the marking

ARCOSTOP is supplied equipped with:

User Manual, Installation Sheet, Technical Data Sheet, External Sensors Insertion Diagrams

IMPORTANT: For the application of the ARCOSTOP System, NO MODIFICATIONS TO THE EXISTING PV CIRCUITS ARE NECESSARY as the toroid sensors directly take the signal to be monitored, simply by inserting the relevant strings into them. No electrical contact or other derivation is therefore necessary.

It is not even necessary to take PV voltages from the existing system, nor to modify the DC side circuits to take the signal. No reports for changes to schemes must therefore be sent to the Control Body.


Technical, commercial and corporate services and assistance
Indications on the best possibility of RETROFIT installation
Assistance in defining the intervention in general and in particular
Possibility of conducting preliminary inspections with Qualified Personnel
Availability to assist customers in presenting the system to the Provincial Fire Brigade Command
Acceptance of specific requests
Supported by the local company with qualified personnel in both the installation and commissioning phases
Optional consultancy services
Assistance in defining the intervention in general and in particular
Design of the ARCOSTOP mitigation system
ARCOSTOP system certification directly from a fire prevention professional
Assignment to an external technician for the drafting of documentation useful for the presentation of final fire prevention practices (e.g. SCIA)

Technical information

For further data see specification N°2022/50 of 02/20/2022 entitled: ARCOSTOP® Technical specification for mechanical and electrical interfacing
15-30 Vdc
To be supplied via CABUR XCSF Series power supply, amperages to be sized based on the quantity of devices
In the case of buffer batteries, use the CABUR model XCSBC battery charger accessory card
30 mA in Standby
45 mA with active alarm
1 kV
Resin-coated toroid sensor 
Internal diameter 25.8 mm
External diameter 64.6 mm 
height 22.0 mm
weight 350 grams 
with 5 m cable
Multiple rotary switch Set C
Multiple rotary switch Set L
Trimmer RV1
Vdc reading via contacts available on the front of the device
Reading in OHM via contacts available on the front of the device.

Construction Data

Model V 5.1
Height mm. 117
Width without connectors mm. 86
Width with BNC footprint mm. 105
Thickness mm. 35 (2 modules)
OUT1 relay output (terminals 1 - 2 - 3)
CONTACTS: maximum current NO-NC-C 250V dc 2A
30 Vdc 2A
24Vdc 1.25A
125Vac 0.4A (UL)
OUT2 relay output (terminals 4 - 5 - 6)
CONTACTS: maximum current NO-NC-C 250V dc 2A
30Vdc 2A
24Vdc 1.25A
125Vac 0.4A (UL)
Indication light L1 red
Arc flash detection in progress
L2 red light indication
Arc flash detected and purchase
L3 green light indication
Device running
Terminal section: power indicator
mm2 2.5