The Lowdown on Welding Power Sources
Jeff Herb of Miller Electric explains why no welding power source solution can fit all needs, then shows how an understanding of your application, your future needs and your environment will help you pick the right power source.
Posted: May 24, 2013
Traditional transformer-style welding power sources are considerably larger and draw more power, which ultimately adds up to a larger utility bill and limits the number of power sources you can hook up to your building’s existing power/breakers.
Inverter-based power sources, however, offer a lower power draw and give users more flexibility into the number of units that can be run on existing power.
By way of example: A 350-amp conventional TIG power source draws 128 amps of input power under a rated load on 230-volt single-phase power.
Under the same circumstances, a comparable TIG inverter only draws 32 amps. This gives companies the flexibility to add more machines and workstations on existing power without having to expand or build in more power.
As many companies are land-locked by their current buildings, being able to produce more in the same amount of space is an excellent way to expand.
SIZE SPACE AND PORTABILITY
Another advantage of inverters over transformer-based power sources is space savings. Using the similar comparison of a 350-amp TIG power source, a transformer-based machine weighs about 500 lb, while a comparable inverter weighs only 135 lb.
It’s also considerably smaller both in height and width, making it much easier to fit into weld cells and move around.
Similar to how the lower power draw allows for more units to be added to existing breakers, smaller units also give you more flexibility to expand by allowing for more arcs in your existing square footage/footprint.
The overall size and weight of welding power sources can be extremely important in the mobility of the power source if it’s required to work around a cell or shop.
Small TIG/Stick inverters can weigh as little as 13 lb, and new portable multiprocess welding power sources weigh as little as 29 lb and provide Stick, TIG and MIG/Flux Cored-capabilities.
While these power sources are suitable for MRO and repair applications, they do not offer the same output capabilities as larger welding power sources.
ADVANCED PROCESSES/CAPABILITIES
As welding power sources have gotten smaller, they have also gotten smarter. Inverter-based power sources, for instance, offer new settings, functions and operating ranges that provide a number of benefits, including increased travel speeds, better arc control, reduced heat input and distortion, reduced pre- and post-weld cleanup, establishing the weld puddle faster, more easily managing the weld puddle and providing extensive memory functions.
Many power sources have significantly simplified pulsing and other variations on traditional processes that help improve weld quality and productivity.
Many power sources are now coming standard with simplified interfaces and built-in programs that shorten the learning curve and get welders up to speed much faster.
A good example is the PipeWorx Welding System where welders ultimately select the process type, wire type and diameter, and shielding gas, and the machine does the rest.
It also simplifies process changeover to the push of a button and eliminates errors associated with switching polarity, cables and hoses that may lead to an undesirable weld or lost time setting up for each process.
A variety of remote control capabilities also now give welders more control over weld settings and parameters at the arc, making it easier than ever to tailor the welding arc to each specific application.
WELDING INTELLIGENCE
The next step of the evolution with welding power sources leads into “welding intelligence.” Weld data monitoring technologies built into welding power sources help to monitor quality and productivity, and provide an interface to the welder (in the weld cell) that arms them with every bit of information they need to properly make a weld, from parameters to sequencing of welds on the part.
It also provides obvious insights into the performance of each weld cell, allowing companies to track such factors as the total number of welds made and total parts welded, percentage of downtime compared to arc-on time, and deposition rates.
Inefficiencies in certain cells are made obvious when each weld cell is compared. This information empowers the welding supervisor to take a closer look at specific cells or stations to determine what the underlying problem may be.
These technologies also help improve quality. A good welding information system helps identify the root causes for a number of quality-related issues, and gives the user indications of where to go to solve the problem.
This helps reduce rework (a drag on productivity), and the cost of a missed weld or defect rises exponentially the further it gets away from the weld cell without being noticed.
The earlier a potential problem is identified, the less it costs to fix. This includes identifying such things as missed welds, under- and over-welding and weld defects.
So whether you’re looking for a more traditional welding power source that you only need to perform one task, day in and day out, or you’re looking for a powerful multiprocess welding system that you can implement to grow with your business, there are many variables to choose from (more than we can cover in this discussion).
Do the research, work with your local distributors and manufacturer representatives, and you’ll be sure to make the best choice for your business.