Many pronounce it "ups", but most of the literature seems to favor "you pee ess", since they use "a UPS" instead of "an UPS". This document will try to follow the literature. Neither pronunciation will get you laughed at by those who are experienced in the field.
Today, I have a duty from my office to monitor new application which should be installed in our remote site. When I was visitting some remote locations, there were some fact that I found there. actually some remote branchs are not equipped with UPS equipment to protect their electricity equipment. they are not too care because they still don't realize how important UPS for IT Equipment.
long time ago people can work without using IT Equipment that need electricity. but now can we make it?We still can work without a lamp, but when we are using telecommunication and Computer equipment to support our job. then why dont we give an attention for the equipment we have.
UPS has internal batteries to guarantee that continuous power is provided to the equipment even if the power source stops providing power. Of course the UPS can only provide power for a while, typically a few minutes, but that is often enough to ride out power company glitches or short outages. Even if the outage is longer than the battery lifetime of the UPS, this provides the opportunity to execute an orderly shutdown of the equipment. Advantages:
- Computer jobs don't stop because the power fails.
- Users not inconvenienced by computer shutting down.
- Equipment does not incur the stress of another (hard) power cycle.
- Data isn't lost because a machine shut down without doing a "sync" or equivalent to flush cached or real time data.
- Absorb relatively small power surges.
- Smooth out noisy power sources.
- Continue to provide power to equipment during line sags.
- Provide power for some time after a blackout has occurred.
- Automatic shutdown of equipment during long power outages.
- Monitoring and logging of the status of the power supply.
- Display the Voltage/Current draw of the equipment.
- Restart equipment after a long power outage.
- Display the voltage currently on the line.
- Provide alarms on certain error conditions.
- Provide short circuit protection.
There are basically three different types of devices, all of which are occasionally passed off as UPSes.
- Standby power supply (SPS). In this type of supply, power is usually derived directly from the power line, until power fails. After power failure, a battery powered inverter turns on to continue supplying power. Batteries are charged, as necessary, when line power is available. This type of supply is sometimes called an "offline" UPS.
The quality and effectiveness of this class of devices varies considerably; however, they are generally quite a bit cheaper than "true" UPSes. The time required for the inverter to come on line, typically called the switchover time, varies by unit. While some computers may be able to tolerate long switchover times, your mileage may vary. [ Some articles in the trade press have claimed that their testing shows that modern PCs can withstand transfer times of 100ms or more. Most UPS units claim a transfer time to battery of about 4ms. Note that even if a computer can stay up for 100ms, it doesn't mean that 100ms switchover is okay. Damage can still be done to a computer or data on it even if it stays up. ]
Other features to look for in this class of supplies is line filtering and/or other line conditioners. Since appliances connected to the supply are basically connected directly from the power line, SPSes provide relatively poor protection from line noise, frequency variations, line spikes, and brownouts.
[Some SPSes claim to have surge/spike suppression circuitry as well as transformers to "boost" voltage without switching to the battery if a modest voltage drop occurs. Often, as a "standby" UPS becomes more featureful it is called a "line interactive" UPS.
- Hybrid [ or ferroresonant ] UPS systems. I only know one vendor who sells them - Best Power, Inc. [ Now called Eaton Powerware. Note that Powerware also sells line interactive and online UPSes. ] The theory behind these devices is fairly simple. When normal operating line power is present, the supply conditions power using a ferroresonant transformer. This transformer maintains a constant output voltage even with a varying input voltage and provides good protection against line noise. The transformer also maintains output on its secondary briefly when a total outage occurs. Best claims that their inverter then goes on line so quickly that it is operating without any interruption in power. Other UPS vendors maintain that the transition is less than seamless, but then again it's not in their best interest to promote Best's products.
[ Note: According to some sources, ferroresonant transformers in an UPS system can interact with ferroresonant transformers in your equipment's power supply and produce unexpected results. On the other hand, ferroresonant UPS systems don't kick off a lot of heat, which is important in some environments. The Moral: Test equipment to make sure it meets your needs before you buy. -npc ]
- What I call "true" UPS systems, those supplies that continuously operate from an inverter. Obviously, there is no switchover time, and these supplies generally provide the best isolation from power line problems. The disadvantages to these devices are increased cost, increased power consumption, and increased heat generation. Despite the fact that the inverter in a "true" UPS is always on, the reliability of such units does not seem to be affected. In fact, we have seen more failures in cheaper SPS units. [ Note, though, that given the same quality inverter, you'd expect the one that runs least to last longest. These devices are often called "online" UPSes. ]
here i have a reference website which can open your eyes how UPS are very important equipment nowadays: