Power provided by the grid is more than up to the job of powering lights and motors, but when you want to power tele- and data communications equipment, or if you are manufacturing microelectronics, you need to take the power that comes from the utility and clean it up. The right kind of UPS (uninterruptible power supply) not only can keep the equipment running during a power failure, it can also provide a clean source of power.

The Other UPS
Power disturbances can cause problems for many types of critical processes, particularly computers, servers, and phone systems that have become increasingly central to all business operations. While many systems are able to shrug off minor fluctuations, larger surges can bring these machines to their knees. And when it comes to making something as delicate and involved as semiconductors—especially when made on a large scale—the damage and financial loss that can result from a surge or even dirty power in such a factory is, well, let’s just say more than substantial.

“The ultimate industry critical in nature from a power point of view is the semiconductor industry,” begins Brad Roberts, power quality systems director at S&C Electric Co., manufacturers of UPS systems. “Each little piece is very, very valuable. The process of making them is incredibly delicate. If the lights blink [meaning there’s a power disturbance] for any of those companies, the result is just devastating. Hundreds of thousands, maybe millions of dollars are lost.”

What Led One Company to a UPS
ST Microeletronics in Phoenix, AZ, is using S&C Electric’s single largest UPS system, which is also the world’s largest outdoor system. Other semiconductor manufacturers are using this system, as well. Installed in 2000, it went online that summer. “Online UPSs are still the predominant solution in most computer centers,” says Roberts. “Semiconductor factories use a mixture of online and offline systems. We’re the leader in medium-voltage equipment, and we’re the only one that builds a large outdoor system.”

PHOTO: ST MICROELECTRONICS

Prior to purchasing S&C Electric’s UPS system, ST Microelectronics didn’t have any power protection. Needless to say, it was a risky situation. “In Phoenix, we’re very susceptible in the summertime to monsoons,” says Joe Murphy, director of site facilities operations at ST’s Phoenix office. “It could be a beautiful day and, all of a sudden, there are wind and storms. When those lightening bolts strike, they hit power lines, and you see interruptions and the tools go down. Just one monsoon could cost millions if a lot of wafers are lost.”

ST Microelectronics found they were losing a lot of wafers, and having to do a lot of reworks as well. That was time and materials lost. “We needed to find something that would protect the system so we could ride through these storms,” Murphy explains. “Very seldom were these total power outages. Most of the time we’d see dips and spikes. But these are just as harmful, because the tools that manufacture these wafers run off microprocessors and they’re very susceptible to power fluctuations.”

“We were doing the best we could to work with the local utility, but unfortunately, with this kind of weather, there’s not much they can do. The 230-kV lines are unprotected. They come into our distribution center. Then we drop those down to 12,470 V,” says Murphy. Initially, the company considered using individual UPS systems at each tool, but there were just too many tools for that to be practical. “So we looked at alternatives to having multiple UPSs; then we came up with S&C Electric’s UPS.”

This UPS—the Purewave 12-MW system, which uses 12,470 V—was costly. At the time ST Microelectronics purchased it, it was $5 million, and since then they’ve added an additional $2.5 million to expand its capacity. The company, however, could justify the cost when they counted the number of wafers lost in comparison to the cost of the unit. In the long run, they came out far ahead.

The Search
Like any smart buyer, ST Microelectronics looked at different alternatives before deciding on S&C Electric’s Purewave 12-MW UPS. It seemed to be the best choice for their particular needs. An alternative they had also considered were generators with flywheels on them. “We would not have had the size to have those,” says Murphy. “We would’ve had to keep them running at all times,” a costly solution, he felt.

ST Microelectronics’s main goals were to find the most economical solutions that were both reliable and would be able to ride them through the majority of the interruptions. “We figured that we had to protect the whole manufacturing area and, to do that, we had to protect the whole building,” says Murphy. “So we protected all the facilities-related equipment and the manufacturing-related equipment.” Although ST had already been familiar with UPS technology—they’ve had UPS systems at other of their sites—they had never before had the opportunity to work with a system as large as S&C Electric’s.

Grooving with the Grid
There are two ways to provide UPS—through online and offline UPS systems. “An online system takes that utility power and basically regenerates it by running it through a rectifier to convert it to DC power (battery power),” Roberts explains. “Then you float a battery there and, if anything goes wrong with the utility, the battery will take over. Then you regenerate the DC power into AC power, which is done in an inverter.” Now there can be clean power at the building.

With online UPS, you don’t know when a problem will occur, so the process of regeneration goes on all the time. The problem is, there’s a cost that goes with it: inefficiency. “You lose energy when you rectify the power, and even more when you invert it back to AC,” elaborates Roberts. With this double-conversion process, you stick power in and you only get about 90% of it out. That means there are losses in the 6% to 10% range to generate that process. That’s not so bad for something protecting your desktop, but when you’re talking about a large building, that can be hundreds of thousands of dollars a year lost.”

So, S&C Electric went to work to create a more effective system geared toward businesses with large energy needs. Roberts says, “On a very large scale, we built an offline UPS system that allows the power to flow directly to the load from the utility. To protect a big factory of the size we’re talking about, you have to be very, very good at doing that. And it’s not easy. So we’ve perfected a system by which we can sense and turn on many thousands of kilowatts of power in about 2 to 4 milliseconds. This system comes out to be physically smaller because it doesn’t have to have all that energy and capability on a continuous basis. And it’s now 99% efficient.”

Speed is of the Essence
When the Purewave 12-MW UPS senses any minor disturbance in any of the three phases of the utility power, it automatically turns itself on and disconnects from the utility. “The typical event lasts less that a tenth of a second. When the utility grid has a disturbance, it takes a minimum of 50 milliseconds to recover, our system fixes it in 2 to 4 milliseconds,” says Roberts. “We can protect it before damage is done.

ST Microeletronics’s UPS is located in the company’s substation, right inside the walls where the grid supply is located. “Power is flowing through the system at all times, and the batteries always have a charge on them,” says Murphy. “When it’s needed, we have a fast switch and, as soon as it sees an interruption, the power will go to the UPS system that will feed the plant. That happens within a quarter of a cycle.”

The savings associated with these large companies by using this kind of system are tremendous. “Although this is not the case with ST Microelectronics,” says Roberts, “other companies have very large generator systems and, if the utility fails totally, then our system runs the plant and then transfers it to the generator.”

How Big and How Much?
For a company with medium-voltage needs, such as ST Microelectronics, Roberts says the most practical choice would be to have a medium-voltage solution. “These companies are pretty unique. It makes more sense than low voltage. With bigger systems, a company is more cost-efficient, not just in price but in operating costs. When a company like ST Microelectronics looks at their whole lifecycle cost, it makes more sense to buy a bigger system from us at medium voltage.”

ST Microelectronics has UPS systems in every one of their factories, all of which are very large—typically several hundred thousand square feet of floor space. Some are even over one million square feet. “The loads in these facilities are probably in excess of 50 watts per square foot,” says Roberts. “ST Microelectronics is 450,000 square feet; the main areas will be in 50-watt-per-square-foot range. You need to protect that critical portion of the factory—where the tools are, the clean room—but not everywhere. At ST, they did choose to protect the entire factory because that was the most expeditious way to get the job done. It was a retrofit.”

Installing the Goods
The installation process was done by S&C, a turnkey company that manufactures the product, installs it (by hiring outside contractors), and maintains it. It took about four months, did not affect the facility or workers, and Murphy maintains that it went quite smoothly. “We had a concrete pads report, we had to do a tie-in to the electrical feeds, and all units had to be put together on the site. After they were tested in Milwaukee, they were shipped here and then assembled again.”

The only real concern ST Microelectronics had was regarding the installation schedule. “It seemed at first like it was getting delayed but we finally got that under control,” says Murphy. In the end, the timing worked out just fine.

Pricing and Maintaining
Each individual company has different factors to consider when it comes to whether they can afford to purchase—or afford not to purchase—a UPS system of this capacity. “Typically, if the payback for the investment is not less than two years, companies won’t do it,” says Roberts. “But if they’re losing $10 million a year and the solution is $5 million, that would probably work.” So the bottom line is, the more able a company is to calculate its losses, the better able a company is to decide whether such a system is a worthwhile investment.

All systems of this nature require maintenance. In most cases, the customer depends on the supplier to provide it. And such is the case with ST Microelectronics and S&C Electric Co. “We have a maintenance agreement with S&C,” says Murphy. “They come in periodically and adjust the machine, and this doesn’t really disrupt it.” But some disruptions, even when there’s nice weather, just can’t be predicted. Murphy recalls the following incident: “One time, they were doing something to the system this past year and they took it off line. It was a sunny day. It was Valentine’s Day, and someone had mylar balloons that hit the 230-KV lines. We heard a big bang with balloons.” Unfortunately, that was one costly holiday for the company.

Roberts points out that one of the benefits of the S&C Purewave 12-MW, 12,470-V system is that it only needs a major inspection once a year. “The customer has the responsibility of changing air filters and things like that maybe once a month. They also pay us to monitor the system remotely,” he says. S&C monitors about 50 sites around the world. “Our computer system checks each one of those systems every night, then reports if everything is fine, or if something happened at a site, like a thunderstorm and a disturbance.

“Our UPS systems have what is called a bypass. That means if the equipment develops a problem, it will take itself out of service and put the customer onto raw utility power. The customers obviously don’t like that,” says Roberts. “They want a quick response. If a malfunction occurs at a customer plant, we get notification via remote alarm system. S&C also sends service engineers—who are on call 24 hours—there immediately.” So if a system is down, it’s not long before it’s up again.

Expectations and Results
For ST Microelectronics, the decision to purchase the Purewave 12-MW system was one that paid off. It has definitely fulfilled the hopes and expectations the company had before buying it. “What we do is we measure the number of saves we have and every time the Purewave system has come on,” says Murphy. “To date we have about 112 saves in the four years we’ve had it.”

Has it ever not worked? Yes. Eight times, to be exact. But ST Microelectronics was not disappointed by this because a lot of times the unit was offline when something happened—which isn’t the same as malfunctioning. And Murphy asserts that when it’s online it always seems to work. It is usually offline because of maintenance. This could mean that technicians are changing batteries or making upgrades to the system.

“Each save is a good payback,” starts Murphy, “but it’s a question of how much was the payback and how much was the hit? In ’01 and ’03, we had the two worst monsoon seasons in awhile. In those particular years we saved millions.”

Courageous Pioneering
Before ST Microelectronics decided to use the Purewave 12-MW UPS, it was not being used much at all. Along with being one of the first companies to use it, ST was also the largest single user. Although there was some reluctance on ST’s part to buy it—because of the unknown factors that come with a product that has not yet been widely used—they went forward with it because S&C Electric was noted for their high-quality product and integrity. In addition, this particular product was best suited for their specific needs. “We have a lot of praise for S&C for their ethical approach,” says Murphy. “They’re very ethical. If there’s a problem, I know about it right away. They always try to update the system to make it even better.” And with S&C covering the installation and maintenance, customers like Murphy never have to deal with an outside party. So, perhaps the lesson here is to know your needs, research your manufacturer’s track record and reputation, and be sure you are clear about the extent of the services the company will provide and how that will serve you. Then you can make an informed decision—with confidence.

AMY SORKIN is an LA-based freelance journalist and copywriter who specializes in marketing communications.

DE - November/December 2005