What Good Solar Installation Looks Like: A Workmanship Checklist

You do not need to be an engineer to use most of it. Many points can be checked by looking, from a safe position, and by asking the installer to show you.

Safety first. Look, do not touch. Solar panels produce DC voltage whenever there is daylight, even with the grid off. Do not open junction boxes, unplug connectors or open the distribution board yourself. Ask the installer to show you anything you want to see up close.

Why workmanship matters as much as equipment

Most buyers compare panels and inverters, because those are named on the quotation. But many of the problems that show up in the first few years, such as hot connectors, insulation faults after rain, rusting structures, roof leaks and nuisance tripping, come from how the system was put together. A UK government-commissioned study of solar fire incidents found installation errors to be the most common identified cause. Our solar fire safety guide explains the risks.

A good quotation names the materials; good workmanship is how they are used. Our quotation and BOQ checklist covers the first part. This guide covers the second.

Diagram

What to check after installation

Structure

Level, fixed, rust-protected

DC side

Tidy, protected, labelled cables

AC side

Correct breakers and earthing

1. Structure

• Straight, level rows with even gaps between panels. Wavy rows usually mean rushed measuring.
• Firm anchoring suited to the roof: anchor bolts or base plates on RCC slabs, purlin fixings on sheet roofs. Nothing should move when pushed gently by hand.
• Correct steel sections and bracing for the height and tilt. Elevated structures need more bracing than low ones. See L2, L3 and elevated structures.
• Corrosion protection on cut ends and welds, not just on the parts that show.
• Panel clamps at the positions the panel manufacturer allows, matched to the frame thickness. No drilled panel frames.
• Roof penetrations sealed so the roof does not leak in the monsoon. Our guide to roof waterproofing with solar covers sealing and ballast.
• Drainage kept clear. Base plates should not sit in pooled water.
• Access left for cleaning and maintenance, with a safe walkway where the roof allows.

2. DC cables and connectors

• Proper DC solar cable, sized for the current and run length, not ordinary house wire. See our solar cable size guide.
• Cables clipped to the structure, off the roof surface and away from sharp steel edges. No cables hanging loose under panels or lying in water.
• UV-resistant ties or clips. Ordinary plastic ties go brittle in Punjab's sun within a few seasons.
• Conduit or trunking where cables run across the roof, down walls or through areas where they can be stepped on or reached by children or animals.
• Sealed wall entries with glands or sleeves, so water and pests cannot follow the cable inside.
• MC4 connectors crimped with the correct tool, fully clicked and locked, with both halves of each joint from the same maker. A pliers-crimped or mixed connector is a common cause of hot joints. See our MC4 connector and earthing guide.
• Connectors kept off the roof surface and out of standing water.
• Positive and negative identified with colour or labels along the run.
• Strings grouped sensibly. Panels facing different directions or in different shade should be on separate strings or MPPT inputs.

3. Inverter and battery location

• Shaded, ventilated and dry, with the clearances the manual specifies. Not in direct afternoon sun or a closed cupboard.
• Mounted firmly on a solid wall at a height that is safe and easy to read.
• Batteries kept out of direct sun, away from escape routes, gas cylinders and children's reach.
• Short, neat battery cables with the correct breaker or fuse close to the battery.
• Wi-Fi signal checked so monitoring works.

Our guide to where to install the inverter and battery explains each point.

4. Protection and the distribution board

• DC isolator between the panels and the inverter, rated for DC and the string voltage.
• DC-rated breakers or fuses on the DC side. An AC breaker used on DC is a red flag. See MCB, MCCB and RCCB explained.
• Surge protection devices on the DC and AC sides, connected to earth.
• AC breaker and RCCB on the inverter output, rated for the circuit.
• A neat board: devices on a rail in a closed enclosure, cables dressed in straight lines, no exposed copper, no loose strands sticking out of terminals.
• Terminals tightened to the torque the device maker specifies; loose terminals heat up over time.
• Correct cable lugs and ferrules on stranded cable, not twisted bare ends.
• Enclosures rated for where they sit, with sealed glands if outdoors.

Our breakers and protection page lists the devices we use, from CHINT and TOMZN.

5. Earthing

• Panel frames and structure bonded to earth with proper connections, not just wrapped wire.
• A dedicated earth connection for SPDs and the inverter as its manual specifies.
• Earth pit accessible for testing, with a cover.
• Corrosion-resistant earth joints.

Our guide to solar earthing, surge protection and DC breakers explains why each point matters.

6. Labels

Labels are cheap and often skipped. They matter for anyone who works on the system later, including firefighters.

• DC isolator labelled and its position obvious.
• Warning labels at the inverter and distribution board that DC is present and the system has more than one supply.
• Each breaker labelled with what it controls.
• Shutdown steps displayed near the inverter, or explained and handed over in writing.
• String labels at the inverter or combiner, so faults can be traced.

7. Commissioning tests

Before handover, the installer should test the system, not just switch it on. Typical checks include:

1. Polarity on every string before connecting to the inverter.
2. Open-circuit voltage of each string, compared with the design.
3. Insulation resistance on the DC wiring.
4. Earth continuity and earth resistance.
5. Operation of breakers, isolators and the inverter's grid protection.
6. SPD indicators healthy.
7. Inverter settings, battery communication and charging settings correct for the equipment.
8. Monitoring connected and showing data.

Ask for the results in writing. For more on testing, see safe commissioning.

8. Handover

• System walk-through: how to switch on and off, read the inverter, and where the isolators are.
• Monitoring app set up on your phone; see our monitoring app guide.
• Documents: invoice, BOQ, manufacturer's warranty documents, equipment serial numbers and, where provided, the layout drawing. Panel serials also let you check that panels are genuine.
• A site left clean: offcuts, packaging and loose bolts removed from the roof. Debris left on a roof can blow into panels or block drains.
• A named contact for after-sales support.

Red flags at a glance

How Solar Works Pakistan installs

Engineering and design are done in-house, with dedicated AutoCAD engineers producing layouts and structure designs where the project needs them. Installation is done by our own teams, not subcontracted crews, with appropriate PPE and electrical safety practice. Structures are designed by our engineers and fabricated and assembled by our teams on site. All necessary tests and checks for safe commissioning are completed before handover, and we train you on operating the system, the inverter and the monitoring app. The panel serial-number list is handed over on every project.

After handover, our structures carry a 3-year structure warranty and our 1-year service warranty applies under the applicable project terms. Manufacturer warranties for panels, inverters and batteries are. Our own engineering staff handle after-sales service, with a 48-hour target to send personnel after a complaint is registered. Small projects are normally completed in about a week, subject to payment, equipment availability and site readiness. See our solar installation services for the full process.

Get today's price or a free site survey

Want your system built to this standard, or a second opinion on an existing one? Talk to our engineers.

• WhatsApp or call: 0336 666 4321
• Email: info@solarworks.pk
• Head office: Main Boulevard, Sargodha Rd, Block F FDA City, Faisalabad
• Lahore branch: 2nd Floor, Jeff Heights, Gulberg, Lahore
• Hours: 9:00 AM to 6:00 PM, daily

We serve customers throughout Punjab, from about 6 kW to megawatt-scale projects, and site surveys are normally free. See our Faisalabad and Lahore pages, or contact us.

Frequently asked questions

How can I tell if my solar system was installed properly?

Look for a firmly anchored, straight structure, cables clipped and in conduit rather than loose, a neat and labelled distribution board, DC-rated protection and earthing. Ask the installer for written commissioning test results.

What tests should be done before a solar system is handed over?

Typical checks include string polarity and voltage, insulation resistance, earth continuity, breaker and isolator operation, SPD status, inverter and battery settings and the monitoring connection. Ask for the results in writing.

Why does cable management matter so much?

Loose cables crack in the sun, rub on sharp edges, sit in water and get damaged by birds and people. That leads to earth faults, lost output and, in the worst cases, fire. Clipped cables in conduit avoid most of these problems.

Is it a problem if my installer used different MC4 connector brands?

Mixing the two halves of a joint from different makers is a known cause of hot joints. Each joint should use matching halves crimped with the correct tool. Ask a qualified technician to check if you are unsure.

Should I pay the final amount before commissioning?

Payment milestones vary by project and are set out in the quotation. Whatever the terms, check the installation against this list and make sure commissioning and handover are complete before you sign off.

Can I use this checklist on a system another company installed?

Yes. It is a general guide to good workmanship. Use it from a safe position, and ask a qualified technician to look at anything that worries you.

Sources

1. Solar Power Portal, "Solar PV fires predominantly caused by installer error, government report concludes" (July 2017, on the BRE study for the UK government)