A warehouse has a fire alarm system that requires a minimum of 20VDC for operation. The system is powered by a 120VAC transformer. If the system draws 10A, what is the minimum transformer rating required?
- A120VA
- B240VA
- 600VA
- D1200VA
Exam tip
Always round up when calculating transformer ratings to ensure the transformer can handle the full load.
Why C is correct
The transformer rating is calculated by multiplying the voltage by the current. In this case, the transformer needs to provide 20V x 10A = 200VA. The closest option is 240VA, but since the transformer must be able to handle the full load, the correct answer is 600VA to ensure it can handle the system's requirements.