Your solar PV quote mentions “lightning protection.” What does this description include? Is the panel side protected, the connection between the inverter and the building, or just one point in the electrical panel? Before finalizing the installation, ask for the protection to be described as a whole.
The useful question is not simply “will you install a surge protector?” It is which points are protected, what arrangement is used, and how its condition will be checked. This guide will help you discuss these matters with the responsible electrician, without having to choose electrical materials yourself.
What is surge protection?
A transient overvoltage is a very brief increase in voltage. It may be associated with atmospheric phenomena or switching operations on the electricity network. Surge protection devices, known as SPDs, limit such peaks and divert the resulting current along the designated protection path.
This is not the same as a standard circuit breaker in the electrical panel. The presence of fuses or circuit breakers does not, by itself, answer whether suitable surge protection is in place. Schneider Electric explains how SPDs work and how they are coordinated with the other protective devices.
Also, an SPD device by itself is not equivalent to a complete external lightning protection system for the building. Do not assume that one device guarantees protection against every lightning event.
Ask about both the DC and AC sides
A solar PV system has a direct current (DC) side, from the panels to the inverter, and an alternating current (AC) side, leading to the electrical installation. Their characteristics and requirements differ. Weidmüller’s documentation for solar PV systems distinguishes between protection for these two sides.
Ask for your proposal to show what protection is planned on each side and what protection is already in place. If the inverter has built-in protection, ask for the exact type and clarification on how it fits into the overall design. The general statement “the inverter has protection” does not describe the entire installation.
Also ask whether wired communication or monitoring lines need to be considered. Their routing is part of the assessment, as described in DEHN’s technical guide to rooftop solar PV systems.
If there is a lightning rod, mention it during the site inspection
A building with an existing external lightning protection system needs to be coordinated with the new installation. The position of the panels, mounting structures and cables must be assessed in relation to the building’s system.
In the design, you may come across terms such as “separation distance,” “equipotential bonding” or different SPD types. These describe technical options that are not interchangeable. DEHN’s guide presents different solutions depending on whether external protection is in place and whether the required separation distance can be maintained.
Give the designer any available plans and the building’s most recent inspection records. If you do not have this information, ask them to note what needs to be investigated. Do not settle for a verbal assurance that the old protection automatically covers the new installation too.
Do not choose based only on the marking “Type 1” or “Type 2”
SPD types relate to different tests and applications; they are not a simple ranking from “good” to “better.” The choice depends on the design, the equipment and the installation location.
If you are comparing two quotes, ask why different arrangements are being proposed. You do not need to compare voltages, discharge currents or conductor cross-sections yourself. You do need a clear answer about the suitability and compatibility of the solution.
For an overall assessment of the proposal, also see the solar PV quote comparison guide.
Agree on what you will receive
The description “complete protection” is useful when it comes with specific deliverables. Before placing the order, ask for clarification on:
- The exact product codes for the protective devices and their corresponding technical datasheets.
- The points covered and anything that requires additional checks or work on the existing building.
- Compatibility with the inverter’s built-in protection and the existing installation.
- The checks that will be carried out and the documentation you will receive.
- The inspection, notification and replacement procedure, when required.
For example, if the quote depends on work to the existing grounding system, ask whether that work is included or is a separate item. This is an illustrative example of how to organize the agreement, not a documented customer incident.
At handover, use the solar PV handover checklist to gather plans, inspection results and operating instructions.
Status indicators need to be interpreted correctly
Many devices have a visual indicator or the option of remote alerts. Ask them to show you which indicator applies to the specific product, where is located and what you should do if it changes. Observe only what is safely visible, without removing covers.
A green indicator does not provide a complete diagnosis of the entire installation or predict the remaining life of the component. Phoenix Contact explains the limitations of a simple status indicator in relation to stress monitoring.
Agree on when the protective devices will be checked and whom to call after a relevant alert or suspicious event. If faults or unusual operation occur after a storm, notify the responsible technician and follow their instructions. Do not attempt repeated restarts or replace components as a test.
Technical protection, the product warranty, and insurance coverage need to be confirmed separately. If you are interested in the latter, read what to ask about solar system insurance.
At Solar Home, we consider the photovoltaic system as part of the property and its electrical installation. Contact us to discuss your project and the clarifications your proposal needs regarding protection, handover, and support.
