The three core cable is use to supply a pumping machine whose motor rating is 4kw which is to be installed at a distance 30m from the main switch. Determine the use of the cable to be used for this installation, if the supply voltage is 400v
To determine the appropriate cable to be used for this installation, we need to consider the power rating of the pumping machine, the distance from the main switch, and the supply voltage. Let's break down the calculation:
1. Determine the current:
The formula to calculate current is: Current (A) = Power (W) / Voltage (V)
Given: Motor rating = 4 kW, Supply voltage = 400 V
Convert kW to W: 1 kW = 1000 W
Current (A) = 4000 W / 400 V
Current (A) = 10 A
2. Determine cable size based on current and distance:
The cable size depends on the current and the distance to ensure efficient power transmission without significant voltage drop.
Based on industry standards, we can refer to cable selection charts to find the appropriate cable size. These charts provide information on cable sizes based on current ratings and distances.
3. Select the cable size:
Refer to a cable selection chart for the specified voltage of 400 V and find the appropriate cable size based on the current rating of 10 A. The chart will provide the recommended cable size for this specific application and distance.
It is important to note that cable selection also depends on other factors such as cable insulation, ambient temperature, and installation conditions. It is recommended to consult an electrical engineer or refer to local electrical codes and regulations for precise cable selection.