Kitchen wiring cable size: which wire for which point

The kitchen point wire, point by point

In a Pakistani kitchen on a 220 V single-phase supply, 2.5 mm² copper carries the general worktop socket circuit at 16 A, 1.5 mm² carries lighting and the exhaust fan at 6 A, and any single appliance that draws more than about 3 kW — a full-size electric oven, an instant geyser, a kitchen AC — is taken back to the distribution board on its own 4 mm² circuit rather than spurred off the sockets. That holds for a run in conduit at normal wall lengths; past about 20 m the socket circuit is decided by voltage drop instead, which is worked out further down.

The single-core wire for those rows is what we draw: 3/.029 single core copper cable for the lights, 7/.029 single core copper cable for the sockets, 4mm single core copper cable for the dedicated circuits and 6mm single core copper cable for the earth.

Why the kettle decides the circuit

A kitchen is not a heavy room on paper. It is a heavy room for ninety seconds at a time, and that is what trips breakers. Take three ordinary appliances on the same worktop, at the top of their typical bands: an electric kettle at 2000 W, a microwave at 1200 W and a toaster at 800 W.

4000 W ÷ 220 V = 18.2 A. The 2.5 mm² cable is fine — it is rated 27 A, and even if the correction factors for conduit, bunching and a Lahore summer multiply out to 0.75 it still carries 27 × 0.75 = 20.3 A. The 16 A MCB is what gives up. That is the correct outcome, not a fault: the breaker is protecting a cable that is doing its job.

So a kitchen with a real appliance load gets two socket circuits, worktop split left and right, rather than one bigger cable. Two 16 A circuits on 2.5 mm² beat one 32 A circuit on 6 mm², because a tripped kettle does not take the fridge down with it. Keep the fridge on the circuit that has nothing else switching on it.

How far the kitchen is from the board

Heat sets the size on short runs, length sets it on long ones. 2.5 mm² drops 18 mV per amp per metre. Hold the whole installation to 3% of 220 V — 6.6 V — and give a final circuit about half of that, 3.3 V, because the run from the meter to the board has already spent the rest.

At the full 16 A the sum is 3.3 ÷ (18 × 16 ÷ 1000) = 11.5 m, which sounds alarming until you notice that a kitchen almost never sits at 16 A. At a realistic steady 8 A the same circuit reaches 3.3 ÷ (18 × 8 ÷ 1000) = 23 m. Between those two numbers is the honest answer: measure the route from the distribution board to the far socket, and if it is over about 20 m take the socket circuit up to 4 mm², which drops 11 mV/A/m instead of 18. Your own length goes into the voltage drop calculator.

How much wire one kitchen takes

Thirteen points is a full kitchen: three lights, an exhaust fan, six worktop and appliance sockets, a fridge socket, an oven point and an instant geyser point. Multiply points by the average run back to the board, then by the number of conductors each run carries.

Lights and exhaust: 4 × 12 × 2.5 = 120 m of 1.5 mm². Sockets and fridge: 7 × 12 × 3 = 252 m of 2.5 mm². Oven and geyser: 2 × 12 × 3 = 72 m of 4 mm². Add 15% for cutting waste and failed pulls and it is 138 m, 290 m and 83 m — at 90 m to a coil, 2 coils, 4 coils and 1 coil. That is one room's share of a house list, not an addition to it; the whole-house method is on how much cable a house needs and a worked plot total is on 5 marla house wiring.

Wiring the kitchen circuits

• Take every dedicated appliance circuit back to the board. A 3 kW oven spurred off a socket point is the commonest way a kitchen circuit ends up warm at the junction box.
• Sockets at 1.1 m above finished floor clear the worktop; the fridge and the washing machine get their own sockets low and behind, on a circuit that is not being switched all day.
• Put the whole kitchen behind a 30 mA RCD, and earth every point — the third core is not optional in a room where hands are wet and appliance bodies are metal.
• Isolate the oven and the instant geyser at a double-pole switch on the wall, so the appliance can be killed without walking to the board.
• Leave one spare way in the board and one spare conduit into the kitchen. Kitchens gain appliances; walls do not gain chases without breaking plaster.

Frequently asked

The cable for this job

2.5MM² · 3 CORE · FLEXIBLE

2.5mm 3 Core Flexible Cable

Factory-direct price

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4MM² · 2 CORE · STANDARD

4mm 2 Core Standard Cable

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The sheathed sizes above suit an appliance tail and a surface run. Wiring in conduit is pulled as single core: 7/.029 copper cable price for the sockets, 3/.029 copper cable for the lights, and 4mm 3 core standard cable where the oven or geyser point needs its own earthed run.