Earthing, Surge Protection and Solar: What Homeowners Should Ask About

The photograph shows equipment that sits in the electrical part of a solar installation. It cannot tell a homeowner how the protective conductors are routed, whether the earthing and bonding are suitable for the property, or why a particular surge protective device was chosen. A project image can start the conversation. It cannot close the safety review.

Earthing is a system, not a single rod

In a solar installation, earthing may involve exposed metalwork, protective conductors, the main earthing terminal, bonding and the earth electrode. The Malaysian Electricity Regulations 1994 require relevant metallic parts to be effectively earthed and require a complete system of earthing conductors connected to earth and effectively maintained. The Regulations also cover protection against earth-leakage current [1].

That does not mean a homeowner should choose a cable size or an earth electrode arrangement from a blog post. Ask the installer to show how the PV frames and electrical equipment are included in the protective path, where the main earthing connection is made, and which tests will confirm continuity and the condition of the installation. The answer should refer to the actual property and the equipment being proposed.

Keep the PV side in the same conversation

A solar system is not only the inverter beside the wall. IEC 60364-7-712:2025 covers the electrical installation of a PV system from the PV modules through to the connection point with the rest of the installation or the utility supply point [3]. IEC 62548-1:2023 with its 2025 amendment also sets out PV-array design requirements for DC wiring, electrical protection, switching and earthing, including provisions related to electric-shock protection, insulation monitoring and earth-fault detection [4].

For a homeowner, the useful request is a clear single-line diagram and an equipment schedule. It should show the PV array, inverter, DC and AC isolation points, protective devices, the route back to the distribution board, and the relevant earthing and bonding connections. The exact arrangement depends on the system design, inverter instructions, supply arrangement and applicable Malaysian requirements.

Surge protection needs a risk assessment

A surge protective device is not a magic shield against every lightning event, and the words “SPD included” do not explain a design. Suruhanjaya Tenaga says that whether an SPD is required in a building depends on the risk assessment, with the SPD assessment following the assessment for the lightning protection system [6]. The Commission also points to MS IEC 62305 methods for building lightning-protection systems [7].

IEC 61643-32 describes the selection, installation and coordination principles for SPDs in PV systems. Its scope considers the PV array, associated cabling, protective devices and inverter, and it addresses SPDs used at different locations and on different kinds of PV installation [5]. In plain terms, the device, location, wiring length, earthing arrangement and coordination with other protection should make sense together.

Put these questions into the proposal:

• Is there an existing lightning-protection system on the building, and has its condition and risk been assessed?
• Is surge protection proposed on the DC side, the AC side or both, and what feature of this installation drives that choice?
• Where will each SPD be installed, and how is it coordinated with the inverter, isolation devices and other protective devices?
• How will the homeowner know that an SPD has operated or needs replacement?
• How are the earthing, bonding and lightning-protection arrangements kept at a safe potential relative to one another?

Isolation and handover matter after the roof work

For a grid-connected installation, the property has the utility supply as well as the PV source. The current Energy Commission guideline for self-consumption solar PV covers people involved in design, installation, testing, commissioning and maintenance, and requires the work to follow the applicable technical and safety requirements [2]. Ask where the isolation points are, what warning labels will be fixed, and how future work on the roof, inverter or distribution board is made safe.

Do not treat a tripped breaker, an inverter warning or a suspected lightning strike as a home repair. TNB advises homeowners to use a qualified solar PV installer and says not to attempt the work themselves [8]. Keep the contact route and the handover documents where the next electrician can find them.

Make programme paperwork answer the safety questions

If a quotation mentions NEM Rakyat, Solar ATAP or self-consumption, ask the provider to identify the current programme document and the utility submission route that apply to your project. The Energy Commission has separate current guidance for NEM Rakyat and NEM GoMEn, and for Solar ATAP [9][10]. A programme name does not replace the electrical drawing, protection review, testing or commissioning record.

Inhome Solar lists solar system installation, documentation and TNB application support, operations and maintenance, and consultancy advisory among its public services [11]. Its project material can show the kind of equipment conversation a buyer may have, but a photograph still does not prove the hidden earthing, SPD choice or test result of an unnamed property [12].

Questions worth keeping with the quotation

Before approval, ask for written answers to the points that apply to your property:

• Which earthing and bonding arrangement is being used, and what part of the installation does it protect?
• Where are the DC and AC isolation points, and what warning labels will be installed?
• What risk assessment supports the lightning and surge-protection arrangement?
• Which SPD make, model and ratings are proposed, and how will a failed module be identified?
• Which tests will be completed before handover, and which results will the homeowner receive?
• Who is responsible for the electrical work, testing, programme documents and future maintenance contact?

Sources used

Publisher: Inhome Solar Sdn Bhd · Updated: 19 September 2026 · Technical suitability, electrical design, structural work, installation details, testing and any applicable approval remain subject to the responsible qualified professionals and the conditions of the property.