USCG Exam PracticeElectrical fundamentals — DC/AC, motors, distribution
A shipboard electrical distribution system is described as 'radial.' Which of the following is a recognized disadvantage of this arrangement?
- A. It requires transformers at every distribution panel, increasing cost.
- ✓ A fault or outage at any upstream point de-energizes all loads downstream of that point.Correct
- C. It feeds critical buses from two directions, creating protection coordination problems.
- D. It requires an automatic bus transfer scheme at every feeder breaker.
Why B is correct
A radial system provides one path to each load; a fault or outage upstream kills everything downstream. Ring/loop and selective layouts are used where a single failure must not cause a blackout. DOE-HDBK-1011 Vol.4 §15-1.