What is the AS/NZS 4777.1 voltage rise limit for solar inverters in Australia?

AS/NZS 4777.1:2016 Clause 3.3.3 requires that the voltage rise from the point of supply to the inverter a.c. terminals (the grid-interactive port) does not exceed 2% of the nominal voltage at the point of supply, calculated using the rated current of the IES. For 230 V single-phase that is 4.6 V; for 400 V three-phase that is 8 V line-to-line (or 4.6 V line-to-neutral). The limit applies to the entire inverter path — inverter cable plus any final subcircuit, submain and consumer mains in series back to the point of supply — not to each segment separately, and it applies in addition to the AS/NZS 3000 voltage drop requirements.

How is voltage rise calculated for a grid-connected solar PV inverter?

Per AC cable segment ΔU = I × (R·cosφ + X·sinφ) × L for single-phase and ΔU = √3 × I × (R·cosφ + X·sinφ) × L for three-phase, where I is the rated current of the IES in amperes (AS/NZS 4777.1 Clause 3.3.3 specifies the rated current of the IES, not a reduced figure), R and X are the conductor resistance and reactance per metre from the AS/NZS 3008.1.1:2025 impedance tables (Tables 4.1–4.10) at the insulation operating temperature, L is the cable route length in metres, and φ is the inverter operating power factor angle. The segment rises are summed across every cable from the inverter to the point of supply, divided by nominal voltage, and compared against the 2% AS/NZS 4777.1 limit.

Does the 2% AS/NZS 4777.1 voltage rise limit include the consumer mains?

Yes. AS/NZS 4777.1 Clause 3.3.3 measures the rise from the point of supply to the inverter a.c. terminals — the network connection point at the consumer mains origin. The consumer mains, submain, final subcircuit and inverter AC cable are all in that path, so their voltage rise contributions add together. Once you set the inverter connection point, the calculator includes every segment in the path automatically.

How do I reduce voltage rise on a solar PV installation that fails the 2% limit?

Work the mitigation hierarchy from cheapest first: (1) shorten the AC cable run; (2) increase the cable cross-sectional area on the segment with the largest absolute rise — doubling CSA roughly halves rise on that segment; (3) switch from single-phase to three-phase inverters where supply allows (cuts current by ~3×); (4) move the inverter connection upstream (e.g. MSB instead of final board); (5) choose copper over aluminium for the inverter cable; (6) cluster smaller inverters across different boards; (7) request a DNSP tap change or feeder upgrade as a last resort.

Does an export-limited inverter still have to satisfy the 2% voltage rise limit?

Yes — the 2% limit always applies. By default AS/NZS 4777.1 Clause 3.3.3 says the rise is calculated from the rated current of the IES, not a reduced export figure, so an export-limited inverter is still assessed at its rated current unless the network agreement says otherwise. The standard's one allowance is for an aggregate IES rating above 30 kVA, where the site's known minimum load may be taken into account. Where your DNSP accepts a compliant AS/NZS 4777.2 hard export limit for the rise calculation, the calculator's Export Limit toggle applies the limited kW to the shared segments downstream of the export-limit measurement point; otherwise size on the full IES rated current.

How does the calculator handle multiple inverters on the same installation?

Add each inverter with its own size, name, AC cable run and connection point. The tool aggregates currents per segment — every inverter whose path crosses a given segment contributes its export current to that segment, so the upstream consumer mains carries the sum of all inverters while each inverter's own AC tail carries only its own current. The final pass/fail verdict checks the worst-case inverter path against the 2% AS/NZS 4777.1 limit.

What is the difference between voltage drop and voltage rise?

Voltage drop occurs on cables supplying loads (current flows consumer-mains to load) and is governed by AS/NZS 3000:2018 Cl. 3.6.2 with a 5% total budget (7% from an on-site substation). Voltage rise occurs on cables exporting from generation (current flows inverter to point of supply) and is governed by AS/NZS 4777.1:2016 Cl. 3.3.3 with a 2% inverter-path limit. The same cable on the same install has both — drop under maximum demand and rise under maximum export — but they are assessed separately: this calculator covers the AS/NZS 4777.1 inverter-path voltage rise, while the ElecAS Voltage Drop calculator covers the load-side drop.

Should I use worst-case power factor for AS/NZS 4777.1 voltage rise?

Yes, where the inverter is configured for any AS/NZS 4777.2 reactive response mode (volt-var, fixed PF other than unity, PF response). Worst-case PF evaluates the rise at the operating PF that maximises ΔU = I × (R·cosφ + X·sinφ) × L, which is typically lagging on cables with non-trivial reactance. Disable worst-case only when the inverter is locked to PF = 1.0 by the DNSP connection agreement and the network operator has accepted unity-PF compliance.

Does AS/NZS 4777.1 require a combined voltage drop and voltage rise check?

Not as a single combined calculation. AS/NZS 4777.1 Clause 3.3.3 states that its 2% voltage rise requirement applies in addition to the voltage drop requirements of AS/NZS 3000, so the two are assessed separately and both must be satisfied — the AS/NZS 3000 load-side drop (up to 5%) under maximum demand, and the 2% inverter-path rise under maximum generation. The underlying aim is to keep the consumer's utilisation voltage inside the AS 60038 range, with the point of supply held at or below 253 V (230 V +10%). This calculator covers the AS/NZS 4777.1 inverter-path voltage rise only; for the load-side drop and maximum demand use the ElecAS Voltage Drop and Maximum Demand calculators.

What cable size do I need for a 5 kW single-phase solar inverter to satisfy the 2% voltage rise limit?

A 5 kW single-phase inverter exports about 21.7 A continuous at 230 V. The minimum compliant cable depends entirely on the total length of every segment between the inverter and the point of supply. As a guide: under ~10 m total path a 4 mm² copper cable typically passes; 10 to 25 m needs 6 mm² to 10 mm² copper; 25 to 50 m typically needs 16 mm² copper. The ElecAS calculator returns the actual smallest standard size after applying the AS/NZS 3008.1.1 impedance values and the AS/NZS 4777.1 2% limit to your specific install.

Does cable temperature affect voltage rise?

Yes. AS/NZS 3008.1.1:2025 publishes its conductor impedance tables (Tables 4.1 to 4.10) at the maximum continuous operating temperature of each insulation class — 75 °C for V-75 PVC, 90 °C for V-90 PVC, X-90 XLPE and R-90 elastomer, and 110 °C for X-110 XLPE and R-110 elastomer. Resistance rises ~0.4% per °C in copper, so an XLPE inverter cable at 90 °C exhibits a few percent more rise than the same conductor sized in V-75 PVC. The ElecAS calculator selects the correct temperature row automatically based on the chosen insulation.

Can I use aluminium cable for solar inverter AC connections?

Yes — aluminium is permitted under AS/NZS 3000 for solar inverter AC cables, particularly on larger commercial systems where the mains and submain are already aluminium. Aluminium has roughly 1.6× the resistance of copper for the same cross-section, so it contributes more voltage rise per metre and is restricted to V-75, V-90 and X-90 insulation (no 110 °C aluminium is manufactured in Australia). Always confirm aluminium-rated terminations on the inverter, isolator and switchboard — many smaller residential inverters specify copper-only terminations.

ElecAS

Voltage Rise Calculator — AS/NZS 4777.1 Solar PV & Inverter Compliance for Australia

Free, browser-based AS/NZS 4777.1 voltage rise calculator built for Australian solar PV designers, CEC accredited installers, electricians and electrical engineers. Models the full inverter-to-point-of-supply path — inverter AC cable, final subcircuit, submains and consumer mains — and applies the AS/NZS 4777.1 Clause 3.3.3 limit that the voltage rise from the point of supply to the inverter a.c. terminals must not exceed 2% of nominal voltage, calculated at the rated current of the IES (4.6 V on a 230 V single-phase system, 8 V line-to-line on a 400 V three-phase system). Supports single-phase and three-phase installations, multiple inverters with shared connection points, asymmetric per-inverter cable runs, worst-case power factor evaluation, export-limited systems, copper and aluminium conductors, V-90 / X-90 / V-75 PVC insulation, multi-core and single-core constructions, the full AS/NZS 3008.1.1 Table 3 installation method library, and the standard 2.5–630 mm² cable size range. Returns a per-segment voltage rise breakdown, total rise in volts and percent, a pass/fail pill against the 2% AS/NZS 4777.1 envelope, automatic suggestion of compliant cable sizes when a segment fails, and a branded PDF voltage rise compliance report ready for the DNSP / network operator submission.

Why this page matters

Who this page is for

CEC accredited solar designers and installers, electrical contractors, distributed generation engineers and DNSP connection specialists checking the inverter-path voltage rise on residential, commercial and industrial solar PV and battery storage installations across Australia and New Zealand.

Relevant standards

AS/NZS 4777.1:2016 (Grid Connection of Energy Systems via Inverters — Installation Requirements, including Clause 3.3.3 voltage rise)
AS/NZS 4777.2:2020 (Grid Connection of Energy Systems via Inverters — Inverter Requirements)
AS/NZS 3000:2018 (Wiring Rules — Clause 3.6 voltage drop budget, Clause 7.3 alternative supply systems)
AS/NZS 3008.1.1:2025 (Cable Selection — Tables 4.1–4.10 conductor R and X impedance values)
AS/NZS 5033:2021 (Installation and Safety Requirements of Photovoltaic (PV) Arrays)
AS 60038 (Standard Voltages — 230 V / 400 V nominal voltage used to express the rise as a percentage)
AS/NZS 4509 (Stand-Alone Power Systems, where applicable)

What this tool helps with

Applies the AS/NZS 4777.1:2016 Clause 3.3.3 inverter-path voltage rise limit — 2% of nominal voltage from the point of supply to the inverter a.c. terminals, calculated at the rated current of the IES and evaluated across every cable segment in the path.
Models the complete path the inverter sees back to the network: inverter AC cable, final subcircuit, submains and consumer mains, with the connection point selectable at the inverter, the final distribution board, the submain board or the main switchboard (MSB).
Supports multiple inverters per project — each with its own size, name and dedicated AC cable run — with results aggregated to a single compliance verdict so multi-inverter and string-inverter installations are sized correctly first time.
Single-phase (230 V) and three-phase (400 V) systems, with the calculator switching between line-to-neutral and line-to-line voltage rise automatically and supporting worst-case power factor evaluation for inverters operating at unity, leading or lagging PF.
Copper and aluminium conductors, multi-core and single-core constructions, V-75 PVC, V-90 PVC and X-90 XLPE insulation, and the standard 2.5 mm² to 630 mm² cable size range — all with impedance values read directly from AS/NZS 3008.1.1:2025 Tables 4.1 to 4.10.
Full AS/NZS 3008.1.1 Table 3 installation method library (M1–M11) — unenclosed in air, enclosed in conduit, buried direct and in underground enclosures — feeding the impedance lookup so the calculated rise matches the real install.
Auto-size assistant flags a failing segment and suggests the smallest standard cable size that brings the inverter-path rise back under the 2% AS/NZS 4777.1 limit, so over-sizing is only proposed where the compliance check requires it.
Export-limit aware — when the inverter is configured with a hard export limit the calculator uses the limited current for the rise calculation, avoiding the false fail that comes from using nameplate output on export-limited systems.
Branded PDF voltage rise compliance report with full project metadata (project name, number, address, designer, revision, date), single-line schematic of the inverter path, per-segment results and a pass/fail summary — ready for the DNSP / network connection application.
Built and reviewed by a Chartered Professional Engineer (CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE Aus) — see the Verification page for the testing and review process.

How to calculate voltage rise for a solar PV inverter under AS/NZS 4777.1

Enter inverter sizes and number of inverters — Add each inverter with its continuous AC output in kilowatts. For string solar add one inverter per string; for multi-inverter systems add all inverters that share the same connection point so the calculator aggregates their current correctly.
Select phases and nominal system voltage — Set Phases to 1 (230 V single-phase) or 3 (400 V three-phase line-to-line / 230 V line-to-neutral). The calculator uses the AS 60038 nominal voltage to convert the per-segment rise into a percentage.
Set the connection point — Pick the consumer board the inverter electrically connects to — MSB (main switchboard), submain board, final distribution board, or directly at the inverter terminals. The calculator turns this into the sequence of cable segments the inverter current flows through back to the point of supply.
Enter each cable segment — For the inverter AC cable, final subcircuit, submain and mains, enter cable size (mm²), conductor (Cu or Al), construction (multi-core or single-core), insulation (V-75, V-90 or X-90) and length in metres. The calculator pulls R and X per kilometre from the AS/NZS 3008.1.1:2025 impedance tables (Tables 4.1–4.10).
Pick the installation method — Select the AS/NZS 3008.1.1 Table 3 installation method M1 to M11 that matches the physical install. The method controls which impedance row the tool reads and how the single-core arrangement (trefoil, flat-touching, flat-spaced) feeds into the reactance.
Set power factor and worst-case mode — Leave Use Worst-Case Power Factor on so the tool evaluates the inverter at the leading/lagging PF that produces the maximum AC current. Untick it only when the inverter is configured to operate at unity PF and you want the rise at PF = 1.
Apply export limit if configured — If the inverter has a hard export limit set by the DNSP connection agreement, switch on Export Limit and enter the limit in kW. The calculator uses the limited current — not nameplate — so the rise reflects the real continuous output.
Review the pass/fail and per-segment breakdown — Each segment shows its own voltage rise contribution and the total rise from the inverter terminals to the point of supply is compared against the 2% AS/NZS 4777.1 envelope. Where a segment fails the auto-size assistant suggests the smallest compliant cable size.
Export the branded PDF compliance report — Fill in the project metadata (project name, number, address, designer, revision, date) and export the voltage rise compliance report. Submit it with the DNSP / network connection application alongside the SLD and protection settings.

AS/NZS 4777.1 voltage rise for solar PV — practical engineering guide

What voltage rise is and why AS/NZS 4777.1 limits it

When a grid-connected inverter exports active power, current flows back through the inverter AC cable, the final subcircuit, the submain and the consumer mains toward the point of supply. The IR + IX impedance of every conductor between the inverter and the network lifts the inverter terminal voltage above the nominal supply voltage. The rise is exactly the mirror image of voltage drop — same impedance values, same length, but in the opposite direction.

AS/NZS 4777.1:2016 Clause 3.3.3 limits the rise from the point of supply to the inverter a.c. terminals to 2% of nominal voltage, calculated at the rated current of the IES. On a 230 V single-phase system the limit is 4.6 V; on a 400 V three-phase system the line-to-line limit is 8 V (or 4.6 V line-to-neutral). The reason the limit is tight is that the inverter monitors voltage at its own terminals: as the rise approaches the AS/NZS 4777.2 over-voltage trip point (255 V default on 230 V), the inverter starts curtailing output (volt-watt response), and a few volts of cable rise turns into kilowatt-hours of lost generation across a year.

The 2% inverter path — what the limit actually covers

The 2% limit applies to the entire inverter path from the inverter AC terminals back to the point of supply (the network connection point — typically the consumer mains origin / network meter). It is not a per-segment limit. The calculator therefore sums the rise on every cable in the path — inverter cable, final subcircuit (where the inverter does not connect directly at a board), submain and consumer mains — and compares the total against the 2% envelope.

The connection point selector in the tool fixes which segments are in the path. An inverter connecting at the MSB only sees the consumer mains. An inverter connecting on a submain board sees the consumer mains plus that submain. An inverter on a final subcircuit sees mains plus submain plus final subcircuit plus its own AC tail. The current in each segment is the inverter export current at that point — for multi-inverter installations, segments downstream of the convergence carry only that inverter, while segments upstream of the convergence carry the aggregated current of every inverter on the same path.

Single-phase vs three-phase behaviour

For a single-phase inverter the voltage rise per segment uses ΔU = I × (R·cosφ + X·sinφ) × L where I is the rated current of the IES in amperes (per Clause 3.3.3), R and X are the AS/NZS 3008.1.1 resistance and reactance per metre, L is the route length in metres and φ is the operating power factor angle. The result is a per-segment rise in volts line-to-neutral, divided by 230 V to express it as a percentage.

For a three-phase inverter the rise is √3 × I × (R·cosφ + X·sinφ) × L (line-to-line) for balanced three-phase output, with the percentage taken against 400 V. Three-phase inverters typically produce one-third the per-phase current of a single-phase inverter of the same kW rating, so the rise on the same cable run is roughly one-third — which is why moving from single-phase to three-phase is often the single most effective mitigation for marginal sites.

Worst-case power factor and AS/NZS 4777.2 volt-var

AS/NZS 4777.2:2020 requires inverters to provide reactive power response — volt-var, volt-watt, fixed PF and PF response modes. In an Australia A region default volt-var the inverter absorbs reactive power as terminal voltage rises (lagging from the grid’s perspective) and exports reactive when voltage falls. At the AS/NZS 4777.2 Australia A default, the inverter can be commanded to operate between roughly 0.8 leading and 0.8 lagging PF.

The worst-case PF mode in the calculator scans the AS/NZS 4777.2 PF envelope and reports the rise at the PF that produces the maximum ΔU. For most cable runs this is the PF that puts cos φ + (X/R)·sin φ at a maximum — typically lagging on cables with significant reactance. Disabling worst-case mode evaluates at PF = 1.0, which is realistic only for inverters configured for unity PF operation with no volt-var.

Mitigation hierarchy — cheapest fix first

When a segment fails the 2% limit, work the mitigation ladder from cheapest to most disruptive. First, shorten the cable run — many failing installations are caused by an inverter mounted on the far side of the roof from the switchboard with an unnecessarily long AC cable. Second, increase the conductor cross-sectional area on the segment that contributes the largest absolute rise (the calculator’s per-segment table makes this obvious). Doubling the CSA roughly halves the rise on that segment.

Third, switch from single-phase to three-phase where the supply allows — the same kW rating produces a third of the current, and the rise drops by a factor of three. Fourth, move the connection point upstream — moving an inverter from a final subcircuit to the submain board removes the final-subcircuit segment from the path entirely. Fifth, choose copper over aluminium for the inverter AC cable — copper has ~38% lower resistance per mm² so the rise on the inverter cable comes down by about a third for the same nominal size.

Sixth, consider inverter clustering — running two smaller three-phase inverters at different boards instead of one large single-phase inverter at the final board halves the per-segment current. Seventh, request a network upgrade or tap change at the distribution transformer — only used when every other mitigation has been exhausted, because the DNSP timeline is months and the cost is borne by the customer.

Export-limited systems and aggregated inverter current

Many Australian DNSPs cap residential and small commercial export to 5 kW single-phase or 15 kW three-phase. By default AS/NZS 4777.1 Clause 3.3.3 requires the voltage rise to be calculated from the rated current of the IES, not a reduced export figure — the standard’s only relief is the note allowing the site’s known minimum load to be taken into account for an aggregate IES rating above 30 kVA. Where the DNSP connection agreement accepts sizing on a compliant AS/NZS 4777.2 hard export limit, the calculator’s Export Limit toggle applies the limited kW to the shared segments downstream of the export-limit measurement point; otherwise leave it off and size on the full IES rated current.

For multi-inverter installations the rise on each segment uses the sum of the currents of every inverter whose path includes that segment. Two 5 kW single-phase inverters at the same final board both contribute their 21.7 A to the submain and mains, but only one contributes to its own AC tail. The tool aggregates the contributions automatically once each inverter’s connection path is set.

Standards reference set and how the tool uses them

AS/NZS 4777.1:2016 sets the inverter-path 2% rule (Cl. 3.3.3) and the installation requirements for grid-connected energy systems. AS/NZS 4777.2:2020 sets the inverter behaviour — over/under voltage trip points, volt-watt and volt-var response curves, anti-islanding and the rated output current that feeds the rise calculation.

Conductor impedance comes from the AS/NZS 3008.1.1:2025 impedance tables (Tables 4.1 to 4.10), with the row chosen by conductor material, insulation operating temperature, construction (multi-core or single-core) and installation method. AS/NZS 3000:2018 Cl. 3.6 sets the separate load-side voltage drop budget (5% from the network, 7% from an on-site substation) — a parallel check handled by the ElecAS Voltage Drop calculator, not this inverter-path tool. AS 60038 fixes the nominal voltage (230 V single-phase, 400 V three-phase) used to express the rise as a percentage. AS/NZS 5033:2021 governs the DC array side and intersects with the AC side at the inverter.

Reviewed by

Wisam Tozah — Associate Electrical Engineer. B.Eng (Electrical), MIEAust, CPEng, NER, NSW DBP, NSW PRE, APEC, IntPE(Aus). LinkedIn.

Frequently asked questions

What is the AS/NZS 4777.1 voltage rise limit for solar inverters in Australia?: AS/NZS 4777.1:2016 Clause 3.3.3 requires that the voltage rise from the point of supply to the inverter a.c. terminals (the grid-interactive port) does not exceed 2% of the nominal voltage at the point of supply, calculated using the rated current of the IES. For 230 V single-phase that is 4.6 V; for 400 V three-phase that is 8 V line-to-line (or 4.6 V line-to-neutral). The limit applies to the entire inverter path — inverter cable plus any final subcircuit, submain and consumer mains in series back to the point of supply — not to each segment separately, and it applies in addition to the AS/NZS 3000 voltage drop requirements.
How is voltage rise calculated for a grid-connected solar PV inverter?: Per AC cable segment ΔU = I × (R·cosφ + X·sinφ) × L for single-phase and ΔU = √3 × I × (R·cosφ + X·sinφ) × L for three-phase, where I is the rated current of the IES in amperes (AS/NZS 4777.1 Clause 3.3.3 specifies the rated current of the IES, not a reduced figure), R and X are the conductor resistance and reactance per metre from the AS/NZS 3008.1.1:2025 impedance tables (Tables 4.1–4.10) at the insulation operating temperature, L is the cable route length in metres, and φ is the inverter operating power factor angle. The segment rises are summed across every cable from the inverter to the point of supply, divided by nominal voltage, and compared against the 2% AS/NZS 4777.1 limit.
Does the 2% AS/NZS 4777.1 voltage rise limit include the consumer mains?: Yes. AS/NZS 4777.1 Clause 3.3.3 measures the rise from the point of supply to the inverter a.c. terminals — the network connection point at the consumer mains origin. The consumer mains, submain, final subcircuit and inverter AC cable are all in that path, so their voltage rise contributions add together. Once you set the inverter connection point, the calculator includes every segment in the path automatically.
How do I reduce voltage rise on a solar PV installation that fails the 2% limit?: Work the mitigation hierarchy from cheapest first: (1) shorten the AC cable run; (2) increase the cable cross-sectional area on the segment with the largest absolute rise — doubling CSA roughly halves rise on that segment; (3) switch from single-phase to three-phase inverters where supply allows (cuts current by ~3×); (4) move the inverter connection upstream (e.g. MSB instead of final board); (5) choose copper over aluminium for the inverter cable; (6) cluster smaller inverters across different boards; (7) request a DNSP tap change or feeder upgrade as a last resort.
Does an export-limited inverter still have to satisfy the 2% voltage rise limit?: Yes — the 2% limit always applies. By default AS/NZS 4777.1 Clause 3.3.3 says the rise is calculated from the rated current of the IES, not a reduced export figure, so an export-limited inverter is still assessed at its rated current unless the network agreement says otherwise. The standard's one allowance is for an aggregate IES rating above 30 kVA, where the site's known minimum load may be taken into account. Where your DNSP accepts a compliant AS/NZS 4777.2 hard export limit for the rise calculation, the calculator's Export Limit toggle applies the limited kW to the shared segments downstream of the export-limit measurement point; otherwise size on the full IES rated current.
How does the calculator handle multiple inverters on the same installation?: Add each inverter with its own size, name, AC cable run and connection point. The tool aggregates currents per segment — every inverter whose path crosses a given segment contributes its export current to that segment, so the upstream consumer mains carries the sum of all inverters while each inverter's own AC tail carries only its own current. The final pass/fail verdict checks the worst-case inverter path against the 2% AS/NZS 4777.1 limit.
What is the difference between voltage drop and voltage rise?: Voltage drop occurs on cables supplying loads (current flows consumer-mains to load) and is governed by AS/NZS 3000:2018 Cl. 3.6.2 with a 5% total budget (7% from an on-site substation). Voltage rise occurs on cables exporting from generation (current flows inverter to point of supply) and is governed by AS/NZS 4777.1:2016 Cl. 3.3.3 with a 2% inverter-path limit. The same cable on the same install has both — drop under maximum demand and rise under maximum export — but they are assessed separately: this calculator covers the AS/NZS 4777.1 inverter-path voltage rise, while the ElecAS Voltage Drop calculator covers the load-side drop.
Should I use worst-case power factor for AS/NZS 4777.1 voltage rise?: Yes, where the inverter is configured for any AS/NZS 4777.2 reactive response mode (volt-var, fixed PF other than unity, PF response). Worst-case PF evaluates the rise at the operating PF that maximises ΔU = I × (R·cosφ + X·sinφ) × L, which is typically lagging on cables with non-trivial reactance. Disable worst-case only when the inverter is locked to PF = 1.0 by the DNSP connection agreement and the network operator has accepted unity-PF compliance.
Does AS/NZS 4777.1 require a combined voltage drop and voltage rise check?: Not as a single combined calculation. AS/NZS 4777.1 Clause 3.3.3 states that its 2% voltage rise requirement applies in addition to the voltage drop requirements of AS/NZS 3000, so the two are assessed separately and both must be satisfied — the AS/NZS 3000 load-side drop (up to 5%) under maximum demand, and the 2% inverter-path rise under maximum generation. The underlying aim is to keep the consumer's utilisation voltage inside the AS 60038 range, with the point of supply held at or below 253 V (230 V +10%). This calculator covers the AS/NZS 4777.1 inverter-path voltage rise only; for the load-side drop and maximum demand use the ElecAS Voltage Drop and Maximum Demand calculators.
What cable size do I need for a 5 kW single-phase solar inverter to satisfy the 2% voltage rise limit?: A 5 kW single-phase inverter exports about 21.7 A continuous at 230 V. The minimum compliant cable depends entirely on the total length of every segment between the inverter and the point of supply. As a guide: under ~10 m total path a 4 mm² copper cable typically passes; 10 to 25 m needs 6 mm² to 10 mm² copper; 25 to 50 m typically needs 16 mm² copper. The ElecAS calculator returns the actual smallest standard size after applying the AS/NZS 3008.1.1 impedance values and the AS/NZS 4777.1 2% limit to your specific install.
Does cable temperature affect voltage rise?: Yes. AS/NZS 3008.1.1:2025 publishes its conductor impedance tables (Tables 4.1 to 4.10) at the maximum continuous operating temperature of each insulation class — 75 °C for V-75 PVC, 90 °C for V-90 PVC, X-90 XLPE and R-90 elastomer, and 110 °C for X-110 XLPE and R-110 elastomer. Resistance rises ~0.4% per °C in copper, so an XLPE inverter cable at 90 °C exhibits a few percent more rise than the same conductor sized in V-75 PVC. The ElecAS calculator selects the correct temperature row automatically based on the chosen insulation.
Can I use aluminium cable for solar inverter AC connections?: Yes — aluminium is permitted under AS/NZS 3000 for solar inverter AC cables, particularly on larger commercial systems where the mains and submain are already aluminium. Aluminium has roughly 1.6× the resistance of copper for the same cross-section, so it contributes more voltage rise per metre and is restricted to V-75, V-90 and X-90 insulation (no 110 °C aluminium is manufactured in Australia). Always confirm aluminium-rated terminations on the inverter, isolator and switchboard — many smaller residential inverters specify copper-only terminations.