Electrical engineering and design

Why this sits alongside the solar work

A solar array is a generator connected to an existing electrical installation. If that installation has undersized protection, poor earthing or an overloaded board, adding generation does not fix any of it — and can make the consequences worse.

We do this work because it is the discipline underneath everything else, not as an upsell.

Scope

Load calculations and demand assessment

Connected load, diversity, demand, and headroom for planned expansion. This determines supply capacity, cable sizes and protection ratings — and, when solar is involved, whether the existing infrastructure can accept the generation.

Protection design

Device selection, ratings, and discrimination so a fault trips the nearest device rather than the whole installation. Documented, so it can be verified.

Earthing and bonding

Electrode arrangement, conductor sizing, and bonding of exposed and extraneous conductive parts. Earthing is not visible once complete, which is exactly why it should be documented and tested rather than assumed.

Panels and automation

Distribution boards and control panels designed, built and tested, with schematics that match what was actually installed. That includes labelling every way, so the person who opens the board in five years is reading a record rather than guessing from cable colours.

Backup and changeover

Essential-load segregation, changeover and transfer arrangements, and integration of an inverter or generator into an existing supply. A changeover that was assembled rather than designed tends to fail in the least convenient direction: sources paralleled that should not be, or an essential board that turns out not to be on the essential side.

Power factor correction

Poor power factor is a penalty on most commercial and industrial tariffs and a cost that many sites carry without noticing. Correction is straightforward once it has been measured: capacitor banks sized from a real power-factor measurement, with attention to harmonics, because installing capacitors on a harmonic-rich supply can make matters worse rather than better.

When the problem is the installation, not the appliance

Several everyday symptoms are usually blamed on equipment when they are actually telling you about the wiring behind it:

• Nuisance tripping that nobody can explain — commonly a protection arrangement that was never coordinated, or an earth-leakage device accumulating leakage from several circuits at once.
• A distribution board that is warm to the touch, or shows discolouration around terminals. This is a loose or degraded termination announcing itself before it fails.
• Lights dimming when a motor starts. Voltage drop, undersized conductors, or a supply with less headroom than the site now needs.
• Equipment failing repeatedly in one location while identical equipment elsewhere survives.
• A burning smell with no obvious source. Stop using the circuit and have it inspected.

Each of these is measurable. We measure before recommending, because replacing equipment to solve an installation problem is how a site pays twice.

Earthing, which nobody sees

Earthing is invisible once complete, so it is the easiest part of an installation to do badly and the hardest to notice. Proper work here means an electrode arrangement suited to the soil conditions, conductors sized for the prospective fault current, bonding of exposed and extraneous conductive parts, and a measured result rather than an assumption.

It matters more, not less, once solar is added: an array introduces a second source, extensive metalwork on the roof, and DC cabling routed through the building. Adding all of that to an installation whose earthing was never verified is the single most common unsafe thing we are asked to inspect.

Testing and documentation

Work is not finished when it energises. Commissioning covers continuity of protective conductors, insulation resistance, polarity, earth-fault loop impedance where applicable, and the correct operation of protection devices. The results are recorded, because a set of test results is what makes the installation’s condition arguable later — by us, by another engineer, or by an insurer.

Documentation at handover is a single-line diagram matching what exists, a protection schedule, panel schematics where panels were built, and a labelled board.

Working on occupied sites

Most commercial and industrial work happens on a site that cannot simply stop. That is a planning problem before it is an electrical one: which circuits can be isolated, when, for how long, and what has to be temporarily supplied in the meantime. We agree that plan before work begins rather than discovering it on the day, and we would rather propose a staged shutdown than improvise a live one.

How this connects to the solar work

If solar is planned, this scope is where its feasibility is actually decided — whether the board can accept generation, whether the earthing is sound, whether protection can be coordinated with an added source, and whether the supply capacity matches what is about to be connected. Sites that skip this stage frequently discover it during a net metering inspection instead, which is a slower and more expensive place to find out.