APC 400kW1MW User Manual download pdf (Page 24)

electrical system for short-term power outages and during the startup time required for diesel

generators for long-term outages. The UPS is very beneficial for momentary outages, sages,

surges, and other deviations from clean, in-phase sinusoidal power. UPS batteries are able to

supply power up to 25 or 30 minutes [1, pp. 75 – 76; 31, para 7].

Figure 3-1 One Line Diagram: Typical Data Center Power Distribution

From the UPS, power is routed to the ATS-2, which is also connected to the generator.

When the ATS-2 senses that there has been an interruption in utility power, it will automatically

signal the generator to start. While the ATS is waiting for the generator to start up, the electrical

load is met by the stored power in the batteries of the UPS. Once the generator is running, after

about 10 to 30 seconds, the ATS-2 transfers the electrical load from the UPS to the generator.

While emergency power is being supplied, the ATS-2 continuously protects against current

feedback to the utility’s system and monitors the status of the utility’s power supply. When the

utility power is back to steady state voltage and frequency, the ATS-2 returns the supply power

to the utility connection. Then, the generator cools down and automatically shuts off [32, para

2-3; 1, p. 75].

From the ATS-2, power is supplied to a main distribution panel (MDP). The MDP then

supplies power to various distribution panels that subsequently provide power for offices and the

IT equipment.

The owner of the facility is able to choose whether or not the office area (non-IT

equipment) will be supplied with uninterruptible power. This decision is dependent on the

1 2 ... 19 20 21 22 23 24 25 26 27 28 29 ... 85 86

No comments

APC 400kW1MW User Manual Page 24