Scope a fixed distribution-board surge protective device after the supply, earthing arrangement, DB condition and existing protection are assessed. An SPD is not a substitute for an MCB, RCCB or building lightning protection system.
A fixed DB-mounted SPD is quoted only after the board, supply and earthing arrangement are reviewed. Send a full DB photo, breaker and label close-ups, property type, known supply details, sensitive loads and any solar, EV charger, generator or lightning-protection information. Fixed DB work is assigned to the appropriate EMA Licensed Electrical Worker.
A model number chosen from a photo is not a complete design. The written scope should show how the proposed device fits the actual installation.
| Assessment item | What to confirm | Commercial effect |
|---|---|---|
| Supply and earthing | Known supply arrangement, phase configuration, earthing arrangement and available site records | These conditions affect the appropriate device arrangement and connection method. |
| Distribution board | Board condition, available ways, main protection, existing MCB/RCCB layout, conductors and labels | An overcrowded, damaged or incompatible board can require separate remedial or upgrade work. |
| Risk and connected systems | Sensitive loads, solar PV, EV charger, generator, external feeds and any building lightning-protection system | Connected systems can require a wider coordinated design rather than one isolated device. |
| Handover | Device make and model, indicator status, labels, agreed electrical checks, shutdown window and applicable warranty terms | The handover should identify what was installed without promising absolute protection. |
| Device or system | Primary role | Use the relevant owner |
|---|---|---|
| Surge protective device | Limits transient overvoltage as part of a coordinated installation | This surge protection installation page |
| MCB | Protects against overcurrent and short-circuit conditions | MCB and RCCB replacement cost |
| RCCB | Detects earth leakage and helps protect against electric shock | MCB and RCCB replacement cost |
| Distribution board | Houses and coordinates the installation's protective devices and circuits | DB box upgrade and replacement |
| Lightning-protection system | Addresses building-level lightning risk through a separately designed system | Separate specialist assessment; it is not bundled here |
A fixed DB-mounted SPD changes an electrical installation and its protective-device arrangement. EMA states that electrical works must be undertaken or carried out by Licensed Electrical Workers, whose authorised scope includes installation, repair, inspection and testing within their licence class. The final work must therefore be assigned to the appropriately licensed LEW for the installation and agreed scope.
Singapore's current SS 638 code-of-practice catalogue entry covers the design, erection and verification of electrical installations, including protective measures and additions or alterations. The LEW should determine the applicable design, product and coordination requirements for the actual premises.
Provide one full-board photo, readable labels, close-ups of existing protection and the property or installation type.
The delivery route confirms whether an inspection is needed and identifies any DB, earthing or connected-system dependencies.
Check the device, connection arrangement, shutdown, exclusions, regulated-work route, checks and handover before booking.
A DB-mounted surge protective device limits transient overvoltage by diverting surge current as part of a coordinated electrical installation. It is different from a plug-in extension strip and must be selected for the actual supply and distribution board.
No. An SPD addresses transient overvoltage, an MCB addresses overcurrent and short-circuit conditions, and an RCCB addresses earth-leakage risk. The devices have different jobs and must be coordinated rather than substituted for one another.
A fixed DB-mounted SPD changes the electrical installation and protective-device arrangement. The work must be assigned to an appropriately licensed EMA Licensed Electrical Worker for the installation class and agreed scope.
No. A correctly selected and coordinated SPD reduces risk within its design conditions, but it cannot guarantee protection from every event or direct lightning effect. Building lightning protection, earthing and equipment-level protection are separate parts of the risk assessment.
Send a clear full-board photo, readable device labels, property type, supply information and details of sensitive loads or connected systems. The response can then separate SPD work from DB upgrades and existing-fault remediation.