Can transformers of different KVA sizes be used to supply a large 120/240V single-phase load when only smaller three-phase loads are available?

Prepare for the Southeast Lineman Training Center Exam with quizzes and detailed explanations. Enhance your skills and knowledge through interactive tests. Get exam-ready!

Multiple Choice

Can transformers of different KVA sizes be used to supply a large 120/240V single-phase load when only smaller three-phase loads are available?

You can feed a large 120/240 V single‑phase load by paralleling multiple transformers on the same two hot lines. The voltage between those lines stays the same, but the current-carrying capacity is the sum of what each transformer can deliver. So even if the transformers have different kVA ratings, they can together supply a larger single‑phase load as long as they share the load appropriately and you size the wiring and protection for the total. In practice, you’d ensure the transformers’ impedance allows fairly even load sharing and use proper fusing, conductors, and a neutral path if the load requires 120 V. This is why the correct answer is that it can be done.

You can feed a large 120/240 V single‑phase load by paralleling multiple transformers on the same two hot lines. The voltage between those lines stays the same, but the current-carrying capacity is the sum of what each transformer can deliver. So even if the transformers have different kVA ratings, they can together supply a larger single‑phase load as long as they share the load appropriately and you size the wiring and protection for the total. In practice, you’d ensure the transformers’ impedance allows fairly even load sharing and use proper fusing, conductors, and a neutral path if the load requires 120 V. This is why the correct answer is that it can be done.

More practice questions