Q34 — Steam Dump I/P Converter Power
041 SDS-K2.02 (2.6)
Given:
Which ONE of the following completes the statement below?
The Steam Dump I/P converters are powered by _(1)_ and a loss of power to the Steam Dump I/P converters will cause the Steam Dumps to fail _(2)_.
Which ONE of the following completes the statement below?
The Steam Dump I/P converters are powered by _(1)_ and a loss of power to the Steam Dump I/P converters will cause the Steam Dumps to fail _(2)_.
| (1) | (2) |
A. (1) C/D 115 VAC Instrument Bus — (2) closed
B. (1) C/D 115 VAC Instrument Bus — (2) as-is
C. (1) A/B 125 VDC Bus — (2) closed
D. (1) A/B 125 VDC Bus — (2) as-is
▶ Show Answer & Explanation
✓ A. Correct. The Steam Dump I/P converters are powered by 115 VAC and a loss of power to the Steam Dump I/P converters will cause the Steam Dumps to fail closed.
✗ B. Incorrect but plausible. Part 1 is correct. For Part 2, other components in the plant fail as-is when power is lost. Consequently, the candidate could incorrectly conclude that the Steam Dumps fail as-is when power is lost to the I/P converters.
✗ C. Incorrect but plausible. For Part 1, Steam Dump blocking solenoids are powered from 125 VDC. Consequently, the candidate could incorrectly conclude that the Steam Dump I/P converters are also powered by 125 VDC. Part 2 is correct.
✗ D. Incorrect but plausible. For Part 1, Steam Dump blocking solenoids are powered from 125 VDC. Consequently, the candidate could incorrectly conclude that the Steam Dump I/P converters are also powered by 125 VDC. For Part 2, other components in the plant fail as-is when power is lost. Consequently, the candidate could incorrectly conclude that the Steam Dumps fail as-is when power is lost to the I/P converters.
Ref: NOS05STDUMP-12 (STEAM DUMP SYSTEM) | LO: NOS05STDUMP-12 (STEAM DUMP SYSTEM), Obj 5 — State the power supply to the following Steam Dump System components: a. Steam Dump System Electro-pneumatic (I/P) converters b. Steam Dump Valve Solenoids | Source: New | Cognitive: Fundamental/Memory
Connections
- Related systems: Steam Dumps, 115V AC
- Related exam: 2019 NRC Written Exam