ATP Power Redundancy & UPS Systems 2

Question 1

Which UPS topology provides zero transfer time during a utility power failure?

Accepted Answer

Double-conversion (online) UPS

Answer

Double-conversion online UPS continuously powers the load from the inverter, so there is no transfer time when utility power fails.

Question 2

In a 2N power redundancy configuration, what happens to the total capacity when one PDU path fails?

Accepted Answer

The remaining path carries 100% of the load at full rated capacity

Answer

In a 2N configuration, each path is sized to carry 100% of the load, so a single path failure results in the surviving path assuming the full load.

Question 3

A static transfer switch (STS) typically has a transfer time measured in:

Accepted Answer

Milliseconds (4–8 ms)

Answer

Static transfer switches typically switch between power sources within 4–8 milliseconds, fast enough for most IT equipment.

Question 4

Which of the following best describes an N+1 UPS redundancy model?

Accepted Answer

One extra UPS module is deployed beyond the minimum needed to support the load

Answer

N+1 redundancy means one additional UPS module is added beyond the N modules required to carry the load, allowing any single module to fail without service interruption.

Question 5

What is the primary advantage of a modular UPS over a traditional monolithic UPS in a data center?

Accepted Answer

Scalability and hot-swap capability for individual power modules

Answer

Modular UPS systems allow individual power modules to be added or replaced without shutting down the system, enabling scalable and maintainable redundancy.

(ATP) Accredited Tier Professional Certification (Cooling & Refrigeration) Practice Test

(ATP) Accredited Tier Professional Certification (Cooling & Refrigeration) Practice Test

ATP Power Redundancy & UPS Systems 2