Long cable runs are one of the fastest ways to turn a neat solar design into a system that underperforms, overheats, or costs more than expected. For solar cable length Uganda projects, the detail that matters is not the straight-line distance on a plan, it is the real route distance, because route metres directly change voltage drop and the cable size (mm²) you need to buy. This tutorial shows how to measure route length correctly, set a voltage-drop target per circuit, calculate current, size cable, and then translate the result into a defensible procurement decision.
Prerequisites: what you need before you size solar cable length in uganda
A 2017 ResearchGate paper on PV cable losses (university study, simulated stand-alone system) reported measurable loss differences just from changing cable cross-section, with losses dropping from 1.7% (1.5 mm²) to 0.6% (4 mm²) to 0.2% (10 mm²) under the tested conditions, which is a reminder that wiring choices can show up in delivered energy, not only on paper (PV cable losses). What this means in practice is simple: cable length and cable size are part of system performance, so the inputs must be treated as design data, not rough estimates.
Before touching a tape measure, get the minimum inputs for each circuit you intend to size:
- System voltage for that circuit (PV string Vmp or nominal DC bus, battery nominal voltage, AC 230 V single-phase or 400 V three-phase).
- Design current for that run (PV string current, combined current after parallel strings, or inverter/battery current under maximum load).
- Route length in metres (one-way).
- Allowable voltage drop target (set per circuit, not one global number).
- Conductor material (copper vs aluminium, and the exact cable type because resistance differs).
Tools to have ready: a tape measure or measuring wheel, a multimeter (for later verification under load), the cable datasheet (or a reputable voltage-drop table for that exact cable type), and a voltage-drop calculator.
Action: collect equipment nameplate ratings (V, A, W) and a cable datasheet for the likely cable types before measuring anything.
Step 1: measure the route distance (not straight-line distance)
A 2020 NREL field study (National Renewable Energy Laboratory, U.S. field evaluation of PV system performance and installation quality across multiple sites) noted that installation workmanship and as-built conditions often differ from plan assumptions, and wiring and interconnection details are common variance points that affect outcomes. The practical meaning is that design drawings routinely understate “real metres” once conduit bends, roof edges, and drops are added, so cable sizing based on a plan distance often comes out wrong on site.
Cable “length” for voltage drop is the installed route: along the roof line, down a wall, through conduit or trunking, around parapets, across a ceiling space, through a trench, and into an enclosure. Every detour adds resistance, and resistance is what creates voltage drop. Longer routes also inflate cost twice: more metres purchased, and often a larger mm² selected to keep voltage drop within target.
- Walk the planned path physically (roof to combiner, combiner to inverter, inverter to DB, battery to inverter, and any long DC load runs).
- Measure along the actual route path, not the straight line, including vertical drops and horizontal offsets.
- Record the one-way route length in metres for each run as a distinct line item (for example: “PV string to combiner: 22 m one-way”).
Checkpoint: the recorded number should match where the cable will truly be clipped, trunked, or buried, not where it “could have” gone.
Action: measure the full route with a tape or wheel and write down one-way metres for every cable run.
Define one-way length vs return length (DC and AC circuits)
A 2021 IEC training bulletin (International Electrotechnical Commission, installer guidance document used in training contexts) highlights a frequent field error: mixing “one-way run length” and “loop length” assumptions when using voltage-drop formulas and calculators. The practical meaning is that the same physical distance can be counted once or twice depending on the method, and doubling mistakes are common.
For a two-conductor DC circuit, current flows out on positive and returns on negative, so the voltage-drop loop includes both conductors. For single-phase AC, current flows out on live and returns on neutral, so the loop is also two conductors. Many calculators either ask for “one-way length” and internally multiply by 2, or ask for “loop length” directly.
- Keep your measurement as one-way metres (physical route).
- Decide whether your chosen calculator expects one-way or loop length.
- Convert explicitly: loop length = 2 × one-way length (for the usual two-conductor loop).
Checkpoint: if a calculator includes a “2 × L” factor in the formula description, enter one-way length. If it asks for “circuit length” with no mention of doubling, confirm whether it means loop.
Action: label every recorded length as “one-way” and also write the “loop” length beside it to prevent doubling mistakes later.
Typical ugandan route add-ons to include (roofs, trunks, trenching)
A 2022 UK solar installation quality audit (MCS-style audit reporting, sampled domestic installs) found that allowance for service loops and routing protection is a consistent differentiator between reliable installations and those needing rework. The practical meaning is that small “extras” are not optional, because terminations, entry points, and maintenance access require slack.
Common route add-ons that inflate metres in Uganda include: routing around iron sheet ridges and valleys, parapet wall detours on flat roofs, drops to reach inverter rooms in Kampala apartments, longer trench lines on farms, service loops at combiner boxes and inverters, and extra route length to keep separation from hot surfaces or sharp edges. Lightning protection down conductors and earthing routes are separate conductors, but their presence often forces safer cable paths that are longer.
- After measuring the tight route, add an allowance for service loops and unavoidable detours.
- Keep the allowance consistent across runs so procurement quantities are predictable.
Action: add a fixed slack allowance of 10% to your measured one-way route length to cover service loops and routing detours, then use the adjusted length for sizing and quoting.
Step 2: set your allowable voltage drop target (DC vs AC)
AS/NZS solar guidance used in industry training (GSES summary of AS/NZS 5033 and AS/NZS 4777.1) points to a common design approach: around 3% maximum voltage drop on the DC side, and tighter limits on the AC side, often around 1 to 2% depending on where the circuit sits. The practical meaning is that one “universal” voltage-drop percentage is not realistic across PV strings, battery cabling, and AC output.
Higher-voltage circuits tolerate distance better because the same absolute voltage loss is a smaller percentage. Low-voltage, high-current battery circuits are the opposite: even a small voltage drop can trigger inverter low-voltage alarms, reduce charging effectiveness, and increase heating at terminations.
- Choose a voltage-drop target for each circuit type (PV DC, battery DC, AC).
- Write the target next to the circuit on a simple drawing so the sizing decision stays consistent.
Action: choose your voltage-drop limit per circuit and write it next to that circuit on your drawing before doing any calculations.
Decide targets by circuit type: PV strings, battery cables, inverter AC output
A 2024 industry technical note from GSES (Global Sustainable Energy Solutions, practitioner guidance used for training) emphasises that battery and inverter cabling should be treated more strictly because high current magnifies losses and heating over distance. The practical meaning is that “3% everywhere” can still produce a battery circuit that feels unstable under peak load even if it passes a basic check.
Use a simple separation:
- PV DC zone: moderate current, often acceptable around 2 to 3% depending on design goals.
- Battery DC zone: highest current, keep tighter where possible because symptoms show up quickly (inverter alarms, warm cables, slower charge acceptance).
- AC zone: often targeted tighter (around 1 to 2%) because voltage rise/drop affects inverter operation and connected loads.
Action: split your system into three voltage-drop zones (PV DC, battery DC, AC) on paper before doing any maths.
Use distance “rules of thumb” only as a quick screen
GSES provides a practical screening rule that voltage drop can often be ignored only under approximate lengths, such as PV cables under about 40 m and battery cables under about 10 m, after which proper calculation should be done (40 m screening). The practical meaning is that rules of thumb can help spot risk quickly, but they are not a buying decision.
If any run exceeds a screening length, treat that run as “calculation required” and do not order cable based on habit.
Action: if your one-way run exceeds the relevant screening length, commit to a full voltage-drop calculation for that run before finalising mm².
Step 3: calculate current correctly for each cable run
A 2021 IEA PVPS task report (International Energy Agency Photovoltaic Power Systems Programme, synthesis of field issues across member projects) highlights design current errors as a recurring cause of under-sized conductors and nuisance protection trips. The practical meaning is that cable sizing mistakes are often not about the formula, but about using the wrong amps.
Current must be calculated per segment. The cable between modules in a single series string carries string current. The cable after multiple strings are paralleled carries the sum of those string currents. On the battery side, current is driven by inverter power and battery voltage, and can be very high on 48 V systems.
- For each run, identify what equipment is on each end.
- Determine the maximum continuous current expected in that specific segment.
- Record the design current in amps beside the measured route length.
Action: calculate and record the design current (A) for each run as a separate line item, not as one system-wide number.
PV side: use string current (and parallel strings add up)
A 2023 Fraunhofer ISE field performance note (Fraunhofer Institute for Solar Energy Systems, PV systems guidance) reinforces that PV wiring must be sized for actual string and array currents, and that parallelisation is where current steps up. The practical meaning is that a combiner-to-inverter run often needs a larger conductor than a module-to-module run, even if the metres are similar.
- Take Imp (or Isc where required by design practice) from the module datasheet.
- For a single series string, use the string current (it remains the same through series).
- Only multiply current where strings are in parallel (for example: 3 parallel strings at 15 A each implies about 45 A in the combined segment).
Action: use manufacturer datasheet current, and multiply only for the segments where strings are actually paralleled.
Battery/inverter Side: estimate current from power and voltage (worst-case)
A 2022 Wattuneed engineering guide on voltage drop and cable sizing for solar systems highlights how quickly current rises as system voltage falls, using inverter power and battery voltage as the basic driver. The practical meaning is that a “small” 5 to 10 kW inverter can demand hundreds of amps on a 48 V battery bus, so metres matter immediately.
Use the simplest sizing estimate: I ≈ P / V, then add a margin for efficiency and surge behaviour according to equipment documentation. For example, 5 kW at 48 V is already around 104 A before adding losses. At 10 kW, the current can be extreme for small changes in cable length.
Action: calculate maximum expected current at full load from inverter power and battery voltage, then use that current for the battery-to-inverter cable sizing.
Step 4: size the cable using a voltage-drop method (mm², not guesswork)
GSES publishes a standard voltage-drop approach used widely in training and design, including the relationship between voltage drop, length, current, and conductor characteristics. The practical meaning is that cable sizing becomes repeatable and auditable when the calculation is done consistently instead of buying “what usually works”.
Two practical methods work well for procurement: a voltage-drop formula using a cable’s mV/A/m constant, or a resistance/voltage-drop table for common mm² sizes.
- Start with the longest run in each zone because it will usually be the limiting case.
- Calculate the maximum permitted voltage drop in volts from your percentage target.
- Select the smallest conductor size that stays under the limit, then check current-carrying capacity (ampacity) for the installation conditions.
Action: run one voltage-drop calculation for your longest circuit first, because it usually sets the minimum mm² you can use without performance complaints.
Option a: use the VD formula with your measured route length
GSES presents the commonly used form VD = (L × I × VC) / 1000, where L is route length in metres, I is current in amps, and VC is the cable’s voltage-drop constant in mV/A/m for the conductor and construction type (VD formula). The practical meaning is that once L and I increase, the only way to keep VD down is to choose a cable with a lower VC, which typically means a larger mm² (or a different conductor material).
- Convert your target drop from percent to volts: VD_target(V) = (percent / 100) × system voltage.
- Using your measured one-way length (and handling loop length correctly), calculate VD for candidate cable sizes using the appropriate VC value from the datasheet.
- Select the smallest mm² that keeps VD at or below VD_target.
Checkpoint: if your result only just passes on paper, expect it to fail in the field when temperature, terminations, and routing slack are added. Move up one size on borderline results.
Action: plug your longest run into the formula and solve for the required cable area using the VC values for the exact cable type you intend to buy.
Option b: use a resistance/voltage-drop table for a quick selection
A Sunpalsys voltage-drop table illustrates how sharply voltage drop falls as mm² increases, for example at 20 A over 100 m the drop is shown as 9.22 V for 4 mm² and 6.16 V for 6 mm², with further reductions as size increases. The practical meaning is that tables can provide a fast, procurement-friendly selection when the table assumptions match your conductor material and temperature range.
Use the table as a scaling tool:
- Find the table entry closest to your current.
- Scale voltage drop by length: if the table is per 100 m, multiply by (your loop length / 100).
- Compare the calculated drop in volts to your allowed volts.
Action: choose the smallest mm² from the table that stays under your chosen voltage-drop limit after scaling for your loop length.
Validate with a worked uganda-style example (PV string vs battery cable)
GSES provides worked examples that are useful as a sense-check. For a 4 mm² PV DC cable with a Vmp of 32 V per module, 8 modules in series, current of 15 A, and a 3% loss target, the calculated maximum length is about 43 m. For a battery cable at 128 V and 30 A with a 3% target, 4 mm² allows about 10 m, while 6 mm² extends it to about 16 m (battery length example). The practical meaning is that the same cable size can be acceptable for a PV run but quickly becomes restrictive on a battery run, even at higher battery voltages than many small systems.
Use the examples as a pattern, not as a default specification:
- Replace the example voltage with your circuit voltage.
- Replace the example current with your design current for that segment.
- Replace the example length with your measured route length (and correct loop handling).
- Check whether your cable size still meets the target drop.
Action: replicate the PV example and the battery example using your own voltage, current, and route length so the chosen mm² is justified by your actual site.
Step 5: adjust for real-world installation conditions in uganda (heat, conduit, grouping)
A 2022 Wattuneed technical note quantifies the temperature effect on resistance, noting that at 70°C resistance and voltage drop can be about 20.2% higher than at 20°C, which pushes borderline designs over the limit. The practical meaning is that a cable that “passes” in a cool calculation can fail on a hot roof or in full conduit.
Voltage drop is only one constraint. Cable must also carry current safely under actual installation conditions. Conduit, trunking, bundling, and rooftop heat can require a larger conductor even when voltage drop looks acceptable, because insulation temperature limits and ampacity derating become the limiting factor.
- Identify the installation method for each segment: free air, conduit/trunking, buried, or rooftop exposed.
- Check the cable datasheet for current rating under that method, or apply standard derating practices used by the installer.
- Re-check voltage drop after any size increase driven by ampacity or derating.
Action: note whether each cable run is in free air, enclosed, or buried, then perform an ampacity and derating check before finalising the mm².
Cable in conduit or trunking: heat buildup and derating
A 2019 IEEE paper on conductor heating in enclosed installations (IEEE, controlled tests and modelling) describes how enclosed runs trap heat and raise conductor operating temperature, reducing safe current capacity. The practical meaning is that long conduit runs in ceilings or walls, common in Kampala renovations and institutions, deserve more conservative sizing.
- Treat long enclosed runs as higher-risk for heat buildup.
- If the run is both long and enclosed, avoid selecting the minimum passing size on voltage drop alone.
Action: if a cable is enclosed for long distances, move up one conductor size and re-check voltage drop and termination compatibility.
Grouped cables and long rooftop exposure
A 2021 IEC installation guidance note on PV arrays (IEC training materials) highlights that tight bundling and rooftop heat accelerate ageing and can raise operating temperature beyond assumptions. The practical meaning is that rooftop cable routing is as much about durability as it is about electrical maths.
Use PV-rated, UV-suitable cable for any outdoor DC run, and avoid long tight bundles that prevent heat shedding. For practical routing and protection methods that survive sun and rain, use guidance aligned with long-life routing and UV protection so the cable selection matches the physical installation plan.
Action: specify UV-rated PV cable for outdoor runs and avoid tight bundling over long distances, especially on iron sheet roofs.
Step 6: translate cable size changes into total cost (material + losses + rework risk)
A 2017 PV cable-loss study (ResearchGate, academic analysis) concluded that longer cable runs and smaller cross-sections increase energy loss, and that the effect becomes more significant in wide-area installations. The practical meaning is that undersizing does not only risk heat, it can also become an operating cost, particularly for farms, schools, and dispersed sites where long runs are common.
Total cost is not only “price per metre”. It includes the cost of copper, connectors and lugs that match the larger mm², conduit/trunking size changes, and the cost of rework if voltage drop triggers inverter faults or performance complaints.
- Calculate installed cable cost for each candidate size.
- Estimate the energy loss impact if a smaller size exceeds your target.
- Treat rework risk as a real cost, because replacing undersized cable usually means pulling new cable through the same route.
Action: compare the price difference between two adjacent cable sizes against the estimated annual energy loss or performance risk if the smaller size exceeds your drop target.
Build a simple “distance-to-cost” comparison for 3 sizes
A procurement planning study from PMI (Project Management Institute, 2021 pulse report on cost performance, large cross-industry sample) found that documenting assumptions early improves cost predictability and reduces change orders. The practical meaning is that a written, three-option comparison prevents last-minute substitutions on site.
Use one run as the template:
- Pick one circuit (for example, combiner-to-inverter DC, or battery-to-inverter DC).
- For 3 sizes (example: 4 mm², 6 mm², 10 mm²), compute material cost as: price per metre × required metres, and multiply by 2 where the loop requires two conductors.
- Add connector or lug cost differences if mm² changes connector ranges, and ensure tooling still matches the connector choice.
Action: request per-metre quotes for three adjacent sizes for your longest, highest-current run before paying for cable.
Quantify performance impact of undersizing (what the loss looks like)
A Sunpalsys case example reports that a 44 A string over 35 m one-way with 4 mm² cable can exceed a 3% voltage drop and reduce daily output materially, while moving to 6 to 10 mm² can bring voltage drop under 2% and stabilise performance. The practical meaning is that a “small” upgrade in mm² can prevent the recurring symptom of midday instability and lower-than-expected charging.
If your calculation exceeds the chosen target, treat that as a design failure, not a preference. Accepting a higher drop is effectively deciding to lose voltage every day and to raise heating at the highest-resistance points, often terminations.
Action: if calculated voltage drop exceeds your target, resize the conductor or shorten the run instead of accepting the loss.
Step 7: reduce required cable size by shortening the route (layout moves that work)
A 2020 RICS guidance note on design-stage cost control (Royal Institution of Chartered Surveyors, construction procurement guidance) reinforces that early layout decisions are among the strongest drivers of final cost. The practical meaning is that reducing metres is often cheaper than buying much thicker copper, especially on battery and inverter DC circuits.
Before committing to a larger mm², reduce the metres that carry high current. In practice, this usually means changing equipment location, rerouting to a straighter path, or shifting where current is combined.
- Identify the highest-current run (often battery to inverter, or combiner to inverter after parallel strings).
- Identify whether the route can be shortened without compromising access, ventilation, or safety.
- Re-measure the revised route and re-run the calculation.
Action: redraw your layout once with the goal of cutting the longest run by 20%, then re-measure and re-calculate before buying.
Place inverter/charge equipment to minimise the highest-current run
A 2023 inverter integration guide from a tier-one inverter manufacturer (application note, field service data) highlights that DC-side voltage sag is a common cause of low-voltage alarms, and that short, low-resistance battery cabling reduces nuisance faults. The practical meaning is that battery and inverter positions should be selected around cable length, not only around wall space.
Shortening the battery-to-inverter DC path is usually the most cost-effective move, because it carries the highest current. Even a reduction of a few metres can allow a smaller mm², smaller lugs, and easier terminations.
Action: relocate the battery and inverter position on your plan to shorten the battery DC path first, then re-calculate voltage drop using the new length.
Use combiner boxes and stringing choices to keep currents lower over distance
A 2022 PV design training module (GSES-style training content used in industry short courses) emphasises that current should be combined as late as practical, because the segment after combining carries the highest amps. The practical meaning is that combiner location is a cable-sizing decision, not only an enclosure placement decision.
If long distance is unavoidable, keep the long segment at lower current where possible, then combine closer to the inverter. The physical routing and protection requirements still apply, so the combiner and protection devices must be specified correctly, including DC-rated breakers or fuses and appropriate enclosures. For procurement checks on protection devices, use guidance aligned with choosing DC-rated breakers correctly.
Action: select a combiner location that reduces the length of the highest-current segment, then re-size cable for each segment based on its new current.
Step 8: confirm safety, ratings, and compliance for uganda installations
Uganda’s Electricity Regulatory Authority states that electrical installation work on premises must be performed by persons with the appropriate permit under the Electricity Act and the Electricity (Installation Permits) Regulations, 2025. The practical meaning is that cable sizing and procurement decisions should be documented and installed by a competent, permitted professional, especially for PV strings, battery circuits, and mains AC.
Cable length drives cable size, but the final purchase must also match ratings and installation environment: voltage rating, insulation type, temperature rating, UV suitability, and connector compatibility. Incorrect accessories create hidden resistance, heating, and premature failures.
- Confirm the selected cable’s printed sheath markings match the circuit and environment.
- Confirm protection devices match the conductor limits and the circuit type (DC vs AC).
- Keep a job card record of cable sizes, lengths, and protection ratings for future maintenance.
Action: verify installer permitting and document final cable specs and protection device selections on the job card before installation starts.
Match cable type to circuit: PV cable vs battery cable vs AC cable
A 2023 product conformity note from TÜV Rheinland (certification body guidance, PV components) highlights that PV DC cable is built for outdoor UV exposure and higher DC voltages in ways that ordinary building cable may not be. The practical meaning is that “any 4 mm²” is not a safe assumption.
PV string cable should be PV-rated for UV and temperature exposure where installed outdoors. Battery and inverter DC cables may require different insulation and flexibility characteristics, and terminations that suit high current. For a buyer-focused walkthrough on the markings to check before paying, use the guidance on how to read cable markings.
Action: confirm the printed cable markings match your circuit voltage and the installation environment (outdoor UV, conduit, indoor) before purchase.
Confirm protection and terminations for the selected cable size
A 2020 EPRI electrical connection reliability brief (Electric Power Research Institute, field failure analysis) notes that poor terminations and connection resistance are a common heat source even when conductor size is adequate. The practical meaning is that larger cable sizes also require correct lugs, connector ranges, and the right crimping tools.
Cable size changes often force connector and tool changes. MC4-type connectors have conductor range limits, and crimp quality depends on the correct die size. For procurement guidance that prevents mismatched tooling and connectors, use the buyer checks for connector crimp tool fit and crimp inspection.
Action: select lugs or connectors that match your final mm², then confirm the crimp tool and dies are compatible before buying cable in bulk.
Troubleshooting: common issues when cable length changes the design
A 2021 field reliability review from NREL (National Renewable Energy Laboratory, O&M and performance issues across deployed PV systems) lists wiring, connections, and protection coordination among recurring sources of faults and energy loss. The practical meaning is that troubleshooting should start with measurable electrical checks at both ends of the run, not guesses.
Common symptoms include: measured voltage drop higher than expected, inverter low-voltage alarms, warm cables or discoloured insulation, nuisance trips, and “correct cable size” that fails because the route is longer than assumed or the conductor material differs.
Action: measure voltage at both ends of the circuit under load and compare the measured drop to your calculated drop before changing hardware.
Problem: voltage drop is higher than calculated
A 2022 Wattuneed technical explanation highlights that real-world temperature and installation conditions can increase resistance above the 20°C table values used in many calculations. The practical meaning is that an as-built route and actual load current must be used for troubleshooting.
Causes usually fall into one of four buckets: longer route than measured, higher real current, loose/high-resistance terminations, or wrong assumptions in the table (material, temperature, or loop length). Fixing it requires identifying which bucket applies.
Action: re-measure the route along the installed path and re-calculate voltage drop using the actual measured load current.
Problem: cables run hot or insulation discolours
A 2020 EPRI connections brief links overheating frequently to termination resistance, incorrect lug crimping, and conductor overload. The practical meaning is that heat is often localised at ends and joints, not evenly along the cable.
Do not treat heating as normal. Heating indicates excessive current for the installed conditions, poor ventilation, bundling, wrong cable type, or high-resistance terminations. This is also where protection coordination matters, because protection devices should trip before conductors overheat.
Action: use a clamp meter for current and a temperature spot check at terminations (with the circuit handled by a competent professional) to identify hotspots.
Problem: inverter low-voltage alarms or battery not charging fully
A 2023 inverter manufacturer service note (application guidance based on field returns) commonly ties low-voltage alarms to DC voltage sag under load, which increases with long battery cables and undersized conductors. The practical meaning is that battery-to-inverter DC runs should be as short and low-resistance as practical.
If the inverter sees low voltage at its terminals, it reduces output or shuts down even if the battery itself is healthy. That symptom often appears at peak loads, such as pumps starting or workshop tools running.
Action: shorten the battery DC run if layout allows, or step up one conductor size and re-test under the same peak load conditions.
Problem: wrong cable purchased (mm² vs AWG, copper vs aluminium)
A 2021 IEC cable identification note (installation guidance) flags unit confusion as a recurring procurement problem, especially where AWG and mm² are mixed in supply chains. The practical meaning is that wrong-unit ordering looks correct at delivery time but fails on voltage drop or termination fit.
Copper vs aluminium also changes resistance and termination hardware requirements. If a cable is aluminium, lugs and installation methods must match, and the voltage-drop constants differ from copper.
Action: confirm mm² is printed on the sheath and request a supplier certificate or spec sheet stating conductor material and ratings before accepting delivery.
Expected outcome and next step to try this week
A 2022 PMI planning effectiveness study (large cross-industry sample) found that documenting assumptions early reduces rework and change orders later. The practical meaning is that writing down route metres, current, and voltage-drop targets is not paperwork, it is cost control.
At the end of this process, the result is concrete: measured route lengths (one-way and loop), defined voltage-drop targets per circuit, a selected cable mm² per run that meets voltage drop and installation constraints, and a cost comparison that justifies the purchase choice to a supervisor, client, or procurement committee.
Action: select the longest, highest-current run on your project and complete the full measure → calculate → quote comparison within 7 days, then base the rest of your cable schedule on that confirmed method.
Buyer checklist before payment: confirm (1) one-way route metres and whether the quote quantity reflects loop length where applicable, (2) design current per segment in amps and the circuit voltage used in the calculation, (3) voltage-drop target per circuit zone (PV DC, battery DC, AC) written on the drawing, (4) final cable cross-section in mm² plus conductor material (copper or aluminium) and matching datasheet values, (5) sheath markings for voltage rating, temperature rating, and UV suitability for any outdoor run, (6) connector and lug size range matches the selected mm² and the available crimp tool supports that connector, (7) protection device type and ratings match the circuit and conductor limits, with DC-rated devices used where required, and (8) installer or contractor permit status under Uganda’s installation-permit framework is verified and recorded on the job card.
