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Business: Industrial



Case Study: Industrial Parts Service Inc., Woodstock, Ontario, Canada

Industrial Parts Service Inc. of Woodstock, Ontario, is saving $1,757 a year in energy costs because it bought energy-efficient arc welding machines.

The company

Industrial Parts Service is a 20 employee shop that fabricates assemblies for original equipment manufacturers in the logging, agricultural and construction industries.

The problem

In welding, power is wasted when the welding power source is left running even though the operator is not welding. The operating factor, or number of hours the machine is actually used in a day, is much less than one would expect. Most welding processes will consume 10 to 15 lb. of welding wire per hour if operated continuously. Yet in the average shop, usage is generally less than 2 to 3 lb. per operator, for an overall duty cycle of about 20 percent. The welding power source is idling 80 percent of the time. When looking at power efficiencies in welding, the idle current draw is more important than the draw when welding.

The solution

Lately, many companies have been purchasing inverter-type power sources because of their energy efficiency when idling. Often the inverter brings additional features that may be of value, such as smaller size or improved arc characteristics. On the downside, inverters usually cost more up front.

Industrial Parts Service found a solution that fit its requirements without costing more. The company chose the Panasonic KF-350 arc welding power supply because it has excellent arc characteristics and is energy efficient. The unit goes into hibernation six minutes after the last weld is completed, and it springs back to life the moment the welder touches the gun trigger switch. When idling, the unit consumes about 100 watts, compared with 1500 to 2000 watts for other machines.

The savings

When idling with “energy savings” turned on, the KF-350 consumes 100 VA. A competitive 450-amp machine with similar SCR (Silicon-Controlled Rectifier) technology consumes 1930 VA when idling.

For Industrial Parts Service, electricity costs 10¢/kWh, including service charges. Based on a single shift (2000 hours/year) at a 20 percent duty cycle, the machine is idling for 1600 hours/year. For a welding machine that consumes 100 VA when idling rather than 1930 VA, the annual saving per machine is 2928 kWh, or $292.80. Industrial Parts Service has six Panasonic KF 350 machines in its shop, so the energy-saving hibernation feature saves about $1,757per year.

It's satisfying to be able to save money without really doing anything other than making sure you buy energy-efficient equipment at the outset. When adding new or replacing existing equipment, energy usage should be one of the chief considerations.


Al Atherton, General Manager
Industrial Parts Service
1401 Dundas St., PO Box 20057
Woodstock, Ontario  N4S 8X8
Tel.: 519-537-8095, ext. 230

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