A block of flats is connected to a 240V single-phase supply. Calculate
a) The maximum permissible voltage drop between the point of supply and point of consumption
b) The minimum allowance voltage at any point of consumption in the building
a) The maximum permissible voltage drop between the point of supply and point of consumption in a building is typically limited to 5% or less.
To calculate the maximum permissible voltage drop, we can use the formula:
Maximum voltage drop = Supply voltage * allowed percentage voltage drop
In this case, the supply voltage is 240V, and the allowed percentage voltage drop is 5%.
Maximum voltage drop = 240V * 0.05 = 12V
So, the maximum permissible voltage drop between the point of supply and point of consumption in the building is 12V.
b) The minimum allowance voltage at any point of consumption in the building is typically 85% or more of the supply voltage.
To calculate the minimum allowance voltage, we can use the formula:
Minimum allowance voltage = Supply voltage * allowed minimum percentage voltage at the point of consumption
In this case, the supply voltage is 240V, and the allowed minimum percentage voltage at the point of consumption is 85%.
Minimum allowance voltage = 240V * 0.85 = 204V
So, the minimum allowance voltage at any point of consumption in the building is 204V.