How many amps can a bank of three 100 KVA transformers deliver to a building service if one transformer fails?

To determine how many amps a bank of three 100 KVA transformers can deliver to a building service if one transformer fails, we first need to establish the total capacity of the transformers and how this translates to amperage.

Each transformer is rated at 100 KVA. Therefore, the total capacity of three transformers is 300 KVA (100 KVA x 3). To find the current in amps, we can use the formula:

[

Amps = \frac{KVA \times 1000}{Voltage}

]

Assuming the transformers are supplying power at a standard voltage of 480 volts (which is common for commercial applications), the calculation for three transformers operating at full capacity is as follows:

[

Total Amps = \frac{300 KVA \times 1000}{480V} = 625 Amps

]

When one transformer fails, the capacity drops to that of the remaining two transformers, which equals 200 KVA.

Using the same formula for the remaining two transformers:

[

Amps after one failure = \frac{200 KVA \times 1000}{480V} = 416.67 Amps

]

Rounding this value gives approximately 417 amps. This