DC cable vs AC cable: where the solar side stops and the mains side starts

PILONE CABLES TECHNICAL TEAM

DC cable runs from the panels and the battery to the inverter. AC cable runs from the inverter onward. The two are not interchangeable in either direction.

Our solar DC cable is single-core, XLPE or double-PVC insulated, with a 90°C conductor, built for DC string voltage rather than for the 450/750 V AC of a mains circuit — check the rating printed on the cable. Mains cable is multi-core, PVC insulated, 450/750 V with a 70°C conductor, made for a conduit indoors. The sizing method differs too: on the DC side you work from the conductor's own resistance and a tighter voltage budget, not from the AC current tables.

DC cable vs AC cable, row by row

The copper inside both is the same metal, drawn on the same line. Everything wrapped around it is different, and that is what the choice is about.

Constructions as drawn on the Pilone line in Lahore. Conductor temperature 70°C for PVC and 90°C for the XLPE and XLPO solar constructions; conductor data and stranding classes per IEC 60228; 450/750 V is the fixed-wiring rating for PVC cable to IEC 60227. Check the rating printed on your own cable before connecting anything.
Property	Solar DC cable	AC mains cable
Insulation	XLPE/PVC or double PVC	PVC
Conductor temperature	90°C	70°C
Voltage rating	DC — read the cable print	450/750 V AC
Cores	Single-core, one per pole	2, 3 or 4 core
Conductor class	Class 5 flexible	Class 2 rigid or class 5 flexible
Sizes we draw	0.75–35 mm²	0.75–25 mm² copper
Normal duty	Roof, tray, full sun, all day	Conduit, trunking, chased wall
Sized from	Conductor resistance, Ω/km	Tabulated capacity and mV/A/m

Put plainly: a solar DC cable is a single-core conductor built to survive sun and heat at the DC voltage a panel string reaches, and an AC mains cable is a multi-core conductor built to sit protected indoors at 450/750 V. Neither rating transfers to the other job, and the one that applies to your coil is the one printed on it.

Which cable on which leg of a solar install

The inverter is the boundary. Everything on the panel and battery side of it is DC; everything past its output is ordinary 220 V single-phase AC and is sized like any other circuit. Earthing is a separate conductor on both sides.
Run	Cable	Why
Panel to panel, string to combiner	Solar DC, single-core	Outdoors, full sun, string voltage
Combiner or string to inverter DC input	Solar DC, single-core	Same duty, usually the longest DC run
Battery bank to inverter	Solar DC, largest size on the job	Low voltage, heavy current, tight drop budget
Inverter AC output to the board	Standard cable	Ordinary 220 V circuit, sized to the load
Board to house circuits	Standard or flexible	Nothing about solar changes this side
Array frame and inverter earth	Earth cable	Its own conductor, not a spare core

For the size on each leg rather than the type, the solar panel to inverter cable guide covers the DC run, the solar-to-grid wiring guide covers the AC side, and the inverter battery cable guide covers the leads that give most installs trouble.

Why the battery lead is the fattest cable on the system

AC sizing charts hand you millivolts per amp per metre. On the DC side you work straight from the conductor's resistance, and the sum is short: volts lost = 2 × current × run × resistance ÷ 1000, with resistance in ohms per kilometre and the run measured one way. The 2 is there because the current goes out along one conductor and comes back along the other.

Take 6 mm² class 5 copper, which IEC 60228 caps at 3.3 Ω/km at 20°C, and put it on two different DC runs from the same system.

Both rows use 6 mm² class 5 copper at its IEC 60228 maximum resistance of 3.3 Ω/km, measured at 20°C. A conductor working hot has more resistance than this, so treat these as the best case. Percentages are of the working voltage of that run.
Run	Current	One-way length	Volts lost	Share of the voltage
Panel string at 400 V DC	10 A	25 m	1.65 V	0.4%
Battery bank at 48 V DC	60 A	3 m	1.19 V	2.5%

The working: 2 × 10 × 25 × 3.3 ÷ 1000 = 1.65 V on the string, and 2 × 60 × 3 × 3.3 ÷ 1000 = 1.19 V on the battery lead. Same cable, one-eighth the length, and six times the percentage loss — because a volt is nothing out of 400 and a lot out of 48. That is the whole reason a system runs its panel strings on 4 or 6 mm² and its battery leads on 16 or 25 mm². Step that same 3 m lead up to 25 mm² class 5, capped at 0.78 Ω/km, and the loss becomes 2 × 60 × 3 × 0.78 ÷ 1000 = 0.28 V, or 0.6%.

Run your own figures through the voltage drop calculator before you buy the coil, and remember that the battery lead is the one run where the length is short enough that going two sizes up costs very little.

What goes wrong when mains cable is used on the DC side

Sun. PVC left in direct sunlight on a roof hardens and cracks over a season or two. The XLPE and double-PVC solar constructions exist for that duty; ordinary mains PVC does not.
Heat. A cable on a roof tray in a Lahore June is nowhere near the 30°C the capacity tables assume, and PVC's conductor limit is 70°C against 90°C for the solar build. The margin you lose is the margin you needed.
Voltage. Panels in series add up. 450/750 V is an AC rating for a mains circuit and is not the number to size a DC string against — the solar range is built for DC string voltage instead, and its rating is printed on the cable.
Arcing. DC current does not pass through zero the way AC does, so a DC arc has no natural extinguishing point. This is why DC isolators, connectors and cable are specified for DC duty rather than borrowed from the AC side.
Cores. A DC run is single-core per pole, positive and negative as separate cables. A twin-core mains cable pulled in as a pair is a different construction and is not the same thing.

A solar array is live in daylight and cannot be switched off at the panel. Isolation, polarity, DC breaker and fuse selection, and the earthing of the array frame are all installation-design decisions. Have a licensed electrician or a qualified solar installer confirm the cable, the size and the protection for your system — or start with the cable size calculator.

The cable for each side

SOLAR DC · SINGLE CORE · 90°C XLPE

Solar DC Cable, 0.75 to 35mm²

Single-core class 5 copper, PVC and XLPE/PVC constructions, drawn in Lahore. The two sizes most rooftop systems land on are 4mm solar DC cable and 6mm solar DC cable; battery leads usually want 16mm or 25mm.

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AC MAINS · MULTI CORE · 450/750 V

Standard Cable, 4 to 25mm²

Class 2 stranded copper for the run from the inverter output to the board and every circuit past it. A common inverter-to-board pick is 6mm 3 core cable, or 10mm 3 core cable on a longer run. Where the tail has to bend, take the flexible build.

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Cable is priced off the day's copper rate, so we quote per metre and per coil on WhatsApp rather than publish a figure that goes stale. Send the system size, both run lengths and your city and we will price the DC and the AC side in one message.

Frequently asked

Can I use normal house wire for solar panels?

Not on the panel side. Ordinary PVC mains cable is rated 450/750 V AC with a 70°C conductor and is not built for permanent sun. A panel string sits outdoors all day and can run at a DC voltage well above what a house circuit ever sees. Use the single-core solar DC cable for everything up to the inverter, and mains cable after it.

What is the difference between DC cable and AC cable?

Construction and rating. Our solar DC cable is single-core, XLPE or double-PVC insulated, with a 90°C conductor, rated for DC string voltage rather than for a mains circuit, and built for outdoor exposure. Mains cable is 2, 3 or 4 core, PVC insulated, 450/750 V with a 70°C conductor, and built for a conduit indoors. The copper inside is the same metal; everything around it is different. Read the voltage rating printed on the cable you are given.

Why is solar DC cable single-core?

Because positive and negative are run as separate cables. It keeps the two poles independently insulated for the full DC voltage, lets each be routed and isolated on its own, and suits the connectors used at the panels. A twin-core mains cable used as a pair is a different construction and is not a substitute.

Why does the battery lead need a bigger cable than the panel string?

Because volts lost matter more at low voltage. The same 6 mm² cable that loses 1.65 V on a 25 m string is a 0.4% loss at 400 V but a 2.5% loss on a 48 V battery bank carrying 60 A over 3 m. Battery leads are short and carry heavy current at low voltage, so they get the fattest copper on the system.

Do I need DC cable after the inverter?

No. From the inverter output onward the circuit is ordinary 220 V AC, so it takes standard or flexible mains cable sized to the connected load like any other circuit. DC cable stops at the inverter. The one exception is the battery bank, which is on the DC side even though it sits next to the inverter.

Solar ke liye ghar wala wire chal jayega?

Panel se inverter tak nahin. Ghar wala PVC wire 450/750 V AC ka hai aur uska conductor 70°C tak rated hai; dhoop mein chhat par PVC sakht ho kar phatta hai. Solar DC cable single-core hota hai, XLPE ke saath 90°C, aur DC string voltage ke liye bana hota hai — rating cable par likhi hoti hai. Inverter ke baad 220 V AC side par ghar wala standard ya flexible cable bilkul theek hai.

DC or AC cable, factory-direct

We draw both in Lahore and sell at the day's rate — no dealer margin. Tell us the run and the system size: Punjab in 1–2 days, rest of Pakistan in 2–4.

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