In a series-rated system, the line-side protective device can be in combination with a load-side circuit breaker. Which of the following describes the line-side device options?

In a series-rated system, the line-side protective device can be in combination with a load-side circuit breaker. Which of the following describes the line-side device options?

• A. A circuit breaker
• B. A fuse
• C. A circuit breaker or a fuse
• D. A transformer

Answer: (C)

In a series-rated protection setup, the line-side protective device is chosen to work in concert with the downstream protection and can be either a circuit breaker or a fuse. Both options provide overcurrent protection on the line side while allowing the load-side circuit breaker to handle coordination and selective tripping downstream. A transformer is not a protective device, so it doesn’t describe line-side protection options. Using either a circuit breaker or a fuse on the line side gives the flexibility needed to meet coordination and protection requirements in a series-rated arrangement.

In a series-rated protection setup, the line-side protective device is chosen to work in concert with the downstream protection and can be either a circuit breaker or a fuse. Both options provide overcurrent protection on the line side while allowing the load-side circuit breaker to handle coordination and selective tripping downstream. A transformer is not a protective device, so it doesn’t describe line-side protection options. Using either a circuit breaker or a fuse on the line side gives the flexibility needed to meet coordination and protection requirements in a series-rated arrangement.