Certified Data Centre Professional (CDCP) Practice Exam

A dual source static switch (STS) is designed to provide seamless power transfer between two power sources. This mechanism is critical in data centers where continuous power supply is essential.

The description of a break before make switch accurately captures the function of an STS. In this configuration, the switch momentarily disconnects the current from the primary source before establishing the connection to the secondary source. This approach ensures that there is no short circuit in the system and prevents any overlap of power sources that could lead to instability or damage to connected equipment.

While the notion of "make before break" might imply a continuous connection which is desirable in some applications, it does not apply to the STS in the context of avoiding electrical faults. A "0 second transfer switch" suggests immediate transfer, but in practice, there is typically a microsecond break before making the new connection. Furthermore, a safety switch related to earth leakage serves a different purpose concerning electrical safety rather than being focused on source switching.

Understanding the importance of "break before make" in the context of power reliability and safety in data centers is crucial for design and operational decisions, making it an important concept in the field of critical infrastructure and data centre management.