This article aims to introduce the impact of power outages on the availability and normal operation time of communication power supply systems, and provide quantitative data on normal operation time in relevant practical environments, including the impact of APC UPS on normal operation time. These data also involve the impact of power outage frequency and duration, device restart behavior, and APU UPS reliability related factors. In addition, this article will also list the advantages of extending UPS operation time in improving system reliability. Nowadays, the requirements for the normal operation time of the I system are increasingly advanced, and the reliability policy is generally set at 99.999%. However, numerous factors will become obstacles to achieving this high standard level of the system, and the reliability of communication and power supply is an undeniable obstacle among them. However, the connection between communication power supply reliability and normal operation time is not particularly significant, and the communication power supply reliability at different addresses is generally extremely different, which further complicates the situation. The standardized data on communication electrical reliability is extremely limited. Two extremely important communication and electrical reliability investigations were conducted in the United States, one by Bell Labs and the other by! Completed by BM. Furthermore, considering that Schneider Electric has installed over ten million APC UPS systems and many of them can record power issues, we have also accumulated some data in this area. Power supply issues can be roughly divided into three categories, namely:
1. Power outages or low voltage conditions that can temporarily stop the operation of load equipment
2. Transient voltage that can cause temporary suspension or malfunction of load equipment
3. Transient voltage that may damage the load equipment
This article primarily analyzes the first type of communication power supply issue, which is the impact caused by power outages or low voltage. Therefore, our assumption is that 1) the device has been properly protected by a surge suppressor or UPS and can handle transient voltages, or 2) the actual downtime caused by communication power supply issues will be longer than the time described in this article. The survey data is consistent with Schneider Electric’s rich experience in stacking for many years, and the key points are as follows:
1.At a typical address, there are approximately 15 uniform power outages per year that result in IT system issues.
2.90% of power outages last no more than 5 minutes.
3.99% of power outages last no more than 1 hour.
4. The cumulative total duration of power outages is approximately 100 minutes per year.
The above information varies by location, and in some areas of the United States, such as Florida (which often experiences lightning strikes), the power outage rate is one order of magnitude higher. Some building problems can also increase the power outage rate by up to three orders of magnitude. These data can also reflect the situation in Japan and Western Europe. Based on this information, the normal operation time of regional communication power supply in the United States is around 99.980%, and the annual downtime is about 100 minutes. To achieve the 99.999% normal operating time policy, it means annual downtime, which can only be controlled within 4.8 minutes. Therefore, the difficulty of achieving this policy is also real. The methods for equipment to cope with power outages will greatly extend the practical downtime. When there is a communication power outage, the equipment generally has the following three types of response methods:
1. Restart immediately after electrical rehabilitation
2. Proactively restart after a certain delay
3. Manual restart (manual intervention)