When determining fuse size for a bank, which should be considered?

When determining the appropriate fuse size for a bank of transformers, it is essential to consider the largest kilovolt-ampere (kVA) rating within the bank. This approach is necessary because fuses are designed to protect equipment from overload and faults. By selecting the fuse size based on the largest kVA, you ensure that it can handle the maximum load without nuisance blowing during normal operating conditions.

This is critical because if the fuse is sized too small, it may blow under normal operating conditions when the largest transformer draws its full capacity. Conversely, a fuse sized according to the smallest or an average kVA might not provide adequate protection for the largest transformer, leading to potential damage during overload situations. Therefore, focusing on the largest kVA ensures that all transformers in the bank are adequately protected and can operate safely within their designed capacity.