Your questions - our answers
At INTERSOLAR EUROPE 2021 we had numerous discussions about our QFire. We have collected their most frequently asked questions and our answers for you here.

Where is the fireman's switch mounted?
As we build the boxes customised, we can also offer other amounts of strings. Simply send us your requirements, a specification or the network overview plan of your system to be planned, then we will dimension the QFire appropriately.








Which kind of solar contacts do you use?
We pay attention to brand quality and use the original MC4 plugs. However, since we build the boxes customised, we can also use other plugs on request.








How high may the maximum system voltage per string be?
Our relays can handle 1.200 VDC and other ranges on request.








What type of plugs do you use with the DC circuit breaker?
We pay attention to brand quality and use the original MC4 connectors. However, since we build the boxes customised, we can also use other connectors on request.








How high may the maximum system voltage per string be?
Our relays can handle 1,200 VDC and other ranges on request.








How high is the self-consumption of the relays used?
The relay is a low coil power version with a consumption of < 1 W.








Is the QFire certified?
The switch box has been tested by TÜV Rheinland. An EU declaration of conformity is also available.
Where are the QFire switches built?
We produce our fireman's switch in our premises in the Innovapark Kaufbeuren (near Munich). The goods are also shipped from there.


Do the boxes have to be mounted horizontally or vertically?
The orientation of the box is not really relevant. It should be installed in the shade and protected from the weather.




Is there a difference between DC-21B and DC-21A from competitors?
These are mechanical switches. We do offer an electronically controlled switch that switches off automatically even if the AC mains is lost. In addition, we build the circuits customer- and system-specific.




What is the maximum cable length of the control line between the control box and the switch box?
That would then really only be a question of which cable cross-section to choose or whether the switching signal should first be generated on the roof and the "off switch" only represents a control.




Is there a difference between DC-21B and DC-21A from competitors?
These are mechanical switches. We do offer an electronically controlled switch that switches off automatically even if the AC mains is lost. In addition, we build the circuits customer- and system-specific.
Do you have any further questions?
Write to us at info@q3-energie.de, we will answer all your questions and include you here in the FAQs!