One Size doesn’t fit all when it comes to Surge Protection?
By JD Dodson
Commercial and Industrial facilities are constantly adding equipment to make their facilities more efficient. Some of this equipment comes in the form of energy efficient equipment like a building automation system. More common in production facilities are machinery upgrades that streamline their production. The common thread with these pieces of equipment is the fact that they are more sensitive to voltage and current fluctuation. The fluctuations in technical terms are called transients. As customers recognize the need to protect this equipment by installing surge protection devices, they are confused on the appropriate level of sizing inside their facility. This article is meant to give you a rule of thumb and reasoning behind the correct application.
Service Entrance
First, the service entrance is a common install site for facilities as all clients relate protection at this site to lighting’s influence on damaging equipment. Many studies have been done on the potential damage that lighting can cause to a facility. In a quick synopsis, a lighting strike averages around 20,000 kilo-amperes or 20 kA. In a scenario where lighting strikes a power line near a facility, the lighting will travel in both directions, thus cutting the current impact on the facility in half. Also, the current will dissipate some as it travels to ground thru utility equipment. Taken all the above into consideration, a typical strike will present about 10 kA into a service entrance gear. If you size this unit at 10 kA, then you will be replacing the unit’s arrestors and fuses often. Thus, a recommended 240 kA unit will give significant reliability for over 25 years. There are options of 300 kA and above, but this is an over engineered solution for the application that comes with a hefty price.
Branch Panel
The prevalent mind-set in the market is to only protect at the service entrance as most facility managers believe that electrical disturbances come from outside the facility. The truth is 80% of transients come from inside a facility due to equipment switching. Typical symptoms don’t appear immediately from these transients but over time. Symptoms of internal transients are cumulative damage, premature equipment failure, data losses and nuisance tripping of controls. The appropriate sizing on this panel depends on the amount of amps being delivered to the load. The range runs from a 48 kA unit for a 400 amp panel size up to 160 kA unit for 2,000 amp panel.
Load Protection
As facilities invest millions in new equipment, putting in an extra level of protection at the load is necessary. Sizing for the load runs from 48 kA unit for a 400 amp and below and up to 80 kA for units up to 800 amps. System Shield
The above three stage approach is called the system shield approach (see below) and is recommended by IEEE (Institute of Electrical and Electronics Engineers) to adequately protect a facility. Most clients don’t realize the damage to their equipment over time as they don’t keep adequate logs of motor replacement, control replacement and nuisance trips. Moreover, facilities don’t understand the financial impact of inadequate protection and the relatively inexpensive costs of implementing surge protection in the facility. To get an expert analysis on your facility, please call Rapid Power Management to get a site evaluation.
At the Click of a Mouse
Shoes. iPods. Cameras. Clothes. Relationships. Tangible and intangible. Old and new. All these things can not only be found on the World Wide Web, but purchased at the click of a mouse from any location with access to the Internet.
Enter Woot! Not just a store, but an online community of Wooters, the company offers exclusive deals on a wide variety of items, from consumer electronics and household goods to kitchen accessories, sporting goods, children’s items, and T-shirts every day. And unlike traditional internet retailers, Woot differentiates itself by selling only one item per day – until the clock strikes midnight or the item is completely sold out. “We pioneered what’s now called the flash sale, or promoting only one sale item a day,” said Derek Chapin, CFO of Woot.com. “It’s become an online phenomenon fueled by our active and vocal community members we call Wooters.”
Making its debut on July 12, 2004, Woot.com was founded by electronics wholesaler Matt Rutledge. The Internet retailer is based in Carrollton, Texas, a suburb of Dallas. Business is good but still paying too much?
While experts at sourcing deals for the Woot community, Woot’s leadership realized they were losing money on otherwise easy to remedy expenses, like landscaping and high energy bills.
“We took a look at our overall operating costs and realized there were ways we could cut back,” said Chapin. “But of the opportunities for costs savings that we identified, we felt we could get our fastest ROI by simply cutting down on our energy consumption. We also wanted to take a step toward being more ‘green’ and helping the environment. That’s when we began our search for energy consultants.”
At the end of 2008, the search was over. Following a review of several independent energy procurement companies, Woot found an energy advisor they trusted to get the job done - Rapid Power Management (RPM).
Co-founded by Brad Keating and James “JD” Dodson in June 2002, Rapid Power Management advises leading companies on ways to reduce energy costs through both demand-side and supply-side energy management strategies. They offer a range of services from electricity and gas consulting to power factor correction systems.
“We partnered with RPM because they offered the best experience and knowledge of the energy market. They were responsive to our needs and presented us with realistic goals when it came to deciding what was achievable as a solution,” noted Chapin.
Light Retrofitting
After completing their audit, RPM chose light retrofitting as the best option to fulfill Woot’s needs based off of their current operations. RPM retrofitted Woot’s warehouse and office space. The warehouse is 110,000 square feet and the office area is approximately 60,000 square feet. They warehouse originally featured 400W metal halide lights and T12 fluorescent lights, both of which were antiquated. To correct this situation, RPM replaced the older lights with T-5 Fixtures, which allowed for more illumination and got the job done with fewer fixtures.
“The main challenges we faced in the warehouse were that it was over lit and utilized inefficient fixtures, added Dodson. “Their current light system was out of date because they were utilizing T12 fixtures, which not only gives off poor lighting, but are extremely energy inefficient. The lights were also being left on all the time, contributing to higher energy statements. Our solution, in Woot’s case, was to add a sensor on every fixture that turned the appropriate lights on with activity, and off after a period of inactivity.”
By adding the T5 fluorescent lights, the light quality improved significantly in the warehouse and was much more efficient. The T5 lights are high quality and have a high output. Unexpected Issue
As RPM continued to retrofit the warehouse, they ran into an unexpected situation. The lights in the room where the Woot T-shirts were being produced cast harsh shadows and the lighting was finicky. Making T-shirts requires high light intensity so colors can be verified. The problem was immediately resolved when RPM brought in extra fixtures and placed them in strategic positions.
“The whole process went smoothly,” said Chapin. “RPM didn’t disrupt our business at all because the retrofitting took place after hours. They were extremely customer oriented and kept our needs in mind during the entire project.”
Bottom Line
“We’re in the business of helping companies maximize their savings and minimize their costs,” said Dodson. “We don’t just advise companies from a technical stand point, but also from a financial point of view. With our expertise and understanding of a deregulated energy market, we are able to help these companies tap into the utility tax incentives that they are entitled to.”
RPM was confident this method would best help Woot save the largest amount of money and increase efficiency. The total retrofit installation took about two months during summer 2009 and led to tremendous results. When finished, the lighting load was reduced by over 60 percent, and overall, Woot’s energy bill was lowered by more than 18 percent.
“Not only did our light usage reduce dramatically, there was a shift in the workplace. There was an improvement in the office environment because of a more controlled temperature setting and improved lighting. Employee morale increased, and that’s good for any business. We realized that most of the employees found the new light more pleasing,” Chapin said.
“The results are pretty impressive once you add in the ongoing reduction in utility, such as the Oncor rebate and tax credits. This is something that people need to be more educated about,” said Chapin, “and this is where RPM can help.”
