# What is thumb rule in electrical?

## What is thumb rule in electrical?

Thumb Rules. Cable Capacity. For Cu Wire Current Capacity (Up to 30 Sq.mm) = 6X Size of Wire in Sq.mm. Ex. For 2.5 Sq.mm = 6×2.5 = 15 Amp, For 1 Sq.mm = 6×1 = 6 Amp, For 1.5 Sq.mm = 6×1.5 = 9 Amp.

How much current can 2.5 sq mm wire carry?

For Cable Current Capacity = 4X Size of Cable in Sq.mm, Ex. For 2.5 Sq.mm = 4×2.5 = 9 Amp.

How much current can 1.5 sq mm wire carry?

The 1.5 mm wire load capacity is controlled at 2860W. Reasonable and safest.

### How do you calculate square mm of wire?

Calculating the Area of a Cable

1. As an example, let’s assume we want to know the area for a copper conductor cable having 41 strands of 0.20mm wire.
2. 0.20 × 0.20 = 0.04.
3. 41 × 0.0314 = 1.2874.

How do you calculate cable size from KW?

To calculate the Cable Sizing one needs to divide the voltage running through the cable by the target current. For instance, If your wire has a voltage current of 150 Volts and your target is 30 then you divide 150/30.

Which wire is used for AC?

Air Conditioner Wire Size Chart (1.5-5 Ton Units)

Air Conditioner Tonnage: Max. Wattage (At 10 EER): Min. Wire Size:
1.5 Ton 1,800 Watts 18 AWG Wire
2 Ton 2,400 Watts 18 AWG Wire
2.5 Ton 3,000 Watts 14 AWG Wire
3 Ton 3,600 Watts 12 AWG Wire

## How do I calculate what size wire I need?

How do I calculate wire size for motors?

1. Multiply the resistivity (Ω•m) of the conductor material by the peak motor current (A), the number 1.25, and the total length of the cable (m).
2. Divide the result by the voltage drop from the power source to the motor.
3. Multiply by 1,000,000 to get the result in mm2.

How do I calculate cable size needed?

To calculate the Cable Sizing one needs to divide the voltage running through the cable by the target current. For instance, If your wire has a voltage current of 150 Volts and your target is 30 then you divide 150/30. This gives you your target resistance of 5 which is required.

How much voltage drop is OK?

The National Electrical Code says that a voltage drop of 5% at the furthest receptacle in a branch wiring circuit is passable for normal efficiency. For a 120-volt 15 ampere circuit, this means that there should be no greater than a 6 volt drop at the furthest outlet when the circuit is fully loaded.

### Is MCB required for AC?

Buying an MCB After the stabilizer, the next important accessory needed for your AC’s long life is the MCB- Miniature Circuit Breakers or Molded-case Circuit Breaker. The MCB is an automatically operated electrical switch which protects appliances from damage caused by overload or short circuit.

How many mm is AC wire?

2.5mm^2 wire is good for 18A inside a wall, so you are limited by the 15A sockets. A 220V 15A socket can deliver 3.3kW, and even if the voltage drops to 180V it can still do 2.7kW. Your aircon requires 1.55kW so there is enough power available.

What is 10mm cable used for?

10mm earth cable is suitable for fixed wiring of electrical equipment, lighting and household appliances Usually used for grounding wires.

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