New Welding Inverters Earn Structural Steel Fabricator $105,000 Rebate on Energy Savings; New Fleet Payback in 2.7 Years
Fought & Company (Tigard, Oregon) replaced an aging fleet of welding power sources with new inverters from Miller and earned a $105,000 rebate from Energy Trust of Oregon on an initial investment of $180,000. Fought calculates an additional savings of $24,000/year in energy savings and payback within 2.7 years.
Fought & Company’s fleet of welding equipment at its 170,000-sq. ft. facility in Tigard, Oregon began to age—some ran as old as 30 years. Steve Fugate, quality assurance manager, Fought & Company, worked with company executives and welding personnel to outline a plan to replace the aging equipment. Terry Weir, Fought’s plant manager, tipped Fugate off to an economical way to approach the changeout:
“Our plant manager just finished putting a new dryer system in our main compressor room and got involved with Energy Trust of Oregon,” says Fugate. “Because we became more efficient and our energy use went down, they subsidized part of it. So, the success he h ad there led us to talk about our power consumption in our power supplies.”
The result: Once Fought’s new welders were operational, the company received a rebate check from Energy Trust of Oregon for $105,000 on an initial equipment purchase price of $180,000. Fugate expects his company will save an additional $24,000/year in power savings and achieve payback within 2.7 years based on energy savings and tax incentives; additional savings in lower maintenance costs, reduced downtime and floor space were also realized.
Denver’s new Six
th Avenue Bridge is assembled in Fought’s yard before transfer and erection in Denver.
Denver’s new Six th Avenue Bridge is assembled in Fought’s yard before transfer and erection in Denver.
Structural Steel Fabrication & Flux Cored Welding
Fought is the largest combination bridge and structural steel fabricator on the west coast. Recent structural projects include Portland’s ODS Tower (2,534 tons of steel) and Doernbecher Children’s Hospital (1,723 tons) and portions of the retractable roof on Seattle’s Safeco Field (3,124 tons). The company fabricates bridges and structures throughout the west coast, including Alaska and Hawaii, and as far east as Colorado.
The majority of Fought’s structural work consists of flux cored arc welding (FCAW) on A36, A572 and A588 structural steel plates ranging from ¼-in. to 6-in. Each structural weld meets code (AWS D1.1 Structural Welding Code), and every full-penetration weld undergoes volumetric testing, either x-ray or ultrasonic testing (UT). Typical plates range from 1- to 2-1/2-in. thick and are joined with Hobart Brothers’ Trimark® TM-72 (E70T-1C) flux cored wire shielded by 100 percent CO2.
Transitioning to smaller welding equipment created added space and versatility. Fought’s welders are able to easily move the carted welders and wire feeders around the shop.
Prior to the equipment changeover, Fought fabricated its structural steel with 600-amp transformer-based welders that drew 800 watts of primary power at idle. Each machine took up to 12 sq. ft. of floor space. Matched with older wire feeders, these welders performed adequately until their breakdowns began to affect uptime.
Energy Test Proves Inverter’s Worth
“We hooked all of the equipment up,” says Fugate. ”We did idle loads and power loads on the candidate equipment and then idle loads and power loads on each model of the older equipment. All calculations came back with Miller surpassing the competition.”
|Neil Pence, foreman, Fought & Company, stands with the XMT 456 and 70 Series wire feeder.|
Fugate estimates that, overall, the Miller equipment drew 15- to 20-percent less power than the competitive machines. The biggest differences came when the multiprocess inverters were tested at idle. The old 600-amp welder drew 800 watts, while the XMT 456 drew a mere 12 watts. One key factor involved the machine’s cooling fans. The older machines’ fans kicked on immediately—even at idle—which draws a substantial amount of power. The XMT 456 includes Miller’s Fan on Demand™ feature, which only runs when needed and reduces the amount of noise in the shop as well as the airborne contaminants pulled through the machine.
“Our foreman kept saying that we had a problem with the fans on the XMTs,” says Fugate. “He couldn’t get them to work. Even as we were welding, it wasn’t going on. He was getting a little nervous and then it kicked on. The fan doesn’t run at idle and it has to be under load for awhile before it kicks on.”
“The other advantage, as it relates to power usage, is that these 450-amp machines replaced 600-amp machines,” he says. “We ran 600-amp machines in the past because our welders weren’t confident they could get the duty cycle out of a smaller machine. A 450-amp machine should work with the flux cored wire that we run.”
The XMT 456 features a rated output of 450 amps at 100-percent duty cycle and up to 565 amps at 60-percent duty cycle—more than enough to weld with the 3/32-in. TM-72 flux cored wire, which is rated between 250 and 425 amps. Fought’s typical arc-on time is only about 40 percent. The inverters also manage small primary power fluctuations more efficiently than the older equipment thanks to LVC™ Line Voltage Compensation, which keeps output consistent even if primary power fluctuates ±10 percent.
“In the past, our swing shift would come in and have to reset the machine,” says Fugate. “By the time they started welding, everyone is at home running their air conditioning and our voltage load has changed. So there’s going to be an advantage with what we’re running now.”
While Stick welding—largely used for tacking and repairs—is a much smaller portion of Fought’s operation, the CST 280 also draws far less power (10 watts) than the 600-amp machines it replaces (Fought used the same, large transformer-based machines to Stick weld). It also provides superior arc starting capabilities compared to the older equipment thanks to its Adaptive Hot Start technology. Adaptive Hot Start automatically increases amperage at the start of the weld and prevents the electrode from sticking to the workpiece.
The CST 280 provides superior arc starting capabilities and only draws 10 watts of electricity.
“The arc start is huge,” says Fugate, “because we’re going to get more out of the Stick rod. With the older machines, they’d run a three-inch tack and then slag would develop over the end of it. They smack their stick in (because it won’t start) and they get frustrated with it and throw it away. Now we’re going to use less Stick rod because we’re using it more completely and we’re getting it done faster because the guys aren’t fighting restarts.”
New Fleet Frees Space
The switch to an inverter-based welder also created a massive savings in floor space at the shop. The XMT inverters are matched with a smaller wire feeder, Miller’s 70 Series. Fought now fits a power source and a wire feeder on a cart that was once used solely for a power source.
“Space in our shop is very important,” he says. “We picked up a great deal of floor space because we switched to a much smaller piece of equipment. All of the machines now sit in column lines and reduce the overall footprint. Now we can rack more equipment and pre-stage consumables out there so that guys don’t walk 350 feet to get a 60-lb. spool of wire. Advantages continue to present themselves.”
In the case of the smaller Stick welder, Fought gained 100 percent of its floor space back because those machines are so light that they bolted them to the wall.
“Now 100 percent of that 3-x-4-ft. footprint where the machine used to be is floor space for us to take advantage of,” explains Fugate.
The savings in space and added versatility also allowed them to operate with fewer machines:
“We decommissioned 58 machines and replaced them with 48 because we went from being absolutely fixed to having some versatility with movement,” he says. “That gives us extra savings: 10 machines that we don’t pay property tax on, don’t have to maintain and don’t leave running throughout the shift.”
Quantifiable Results = Quick Payback
The total purchase price for the entire fleet of equipment came out to approximately $180,000. Once operational, Fought received a check from Energy Trust of Oregon for $105,000—approximately 58 percent the total cost of the purchase. Additional savings and a quick payback will come from the continuing energy efficiency. And the old equipment didn’t go to waste, either. Fought donated the older equipment to Portland Community College.
“We’re expecting about a $24,000/year savings. These machines will be paid off before the warranty expires. In 2.7 years we’ll have brand new welding equipment that still saves us $24,000 a year.”
The team that implemented the new process at Fought: Terry Holdahl (Airgas), Les Wallace (Hobart Brothers), Neil Pence (Fought), Steve Fugate (Fought), Ron Gross (Miller Electric Mfg. Co.).