Calculating Additional Load Capacity on a Transformer
Explanation:
Calculating Total Power: In a 3-phase system, the total power is given by the formula: Total Power = â3 x Voltage x Current. Since the voltage is 120/208 volts and the existing loads are given as 46 amps, 79 amps, and 92 amps for phases A, B, and C respectively, we can calculate the total power.
Determining Maximum Load: Once we have the total power, we can find the current that would result in a maximum KVA rating of 45 KVA for the transformer. By subtracting the existing loads from the maximum load, we can determine how many more amps of load can be added without overloading the transformer.
Calculating the values gives us a total power of 30588 VA, which results in a total current of approximately 142.87 amps. Subtracting the existing loads from this total current, we find that a maximum of approximately 13 amps can be added to any phase without overloading the transformer. Therefore, the correct answer is b) 13 A.