In a Delta connection, what multiplier is used to calculate the required fuse size from primary amps?

In a Delta connection, the relationship between line current and phase current is determined by the square root of three, which is approximately 1.73. This factor is critical when calculating the required fuse size from primary amps, as it reflects the way currents share across the three phases in a Delta system.

When you have a current measurement for the primary (line) side in a Delta connection, to find the equivalent phase current, you multiply the line current by 1.73. Therefore, if you're scaling the fuse size based on the line amp rating, using this multiplier ensures you account for the total current that may be drawn across all phases, thereby providing a safe and adequate sizing of the fuses.

This consideration is important in electrical installations to prevent equipment damage or system failures due to insufficient fuse ratings, especially in three-phase systems. Understanding this relationship helps in designing systems that are not only compliant with electrical codes but also efficient and reliable in operation.