How can two single phase transformers be connected to increase capacity?

Connecting two single-phase transformers in parallel is an effective method to increase the capacity of the overall system. When two transformers are connected in parallel, they share the load current, allowing for higher total output capacity than a single transformer can provide. This connection method effectively doubles the capacity if both transformers are of the same rating and properly synchronized in terms of voltage, phase angle, and polarity.

When transformers are connected in parallel, they must meet certain criteria: they should have the same voltage rating, similar impedance values to ensure equal load sharing, and compatible phase relationships. This setup not only enhances capacity but also provides redundancy; if one transformer fails, the other can continue to supply power, thus improving reliability.

Other options like connecting transformers in series, tandem, or cascade do not achieve the goal of increasing capacity in the same way. Series connections can increase voltage levels while limiting current output and do not distribute load effectively. Options like tandem and cascade connections are not standard terminologies for increasing capacity in transformers and their practical applications do not effectively provide the same benefits as parallel connections would in terms of load sharing and capacity augmentation.