SigmaWeld: saving energy, increasing productivity

April 11, 2014 10:59 am

Today more and more states are looking for ways and means to increase their energy availability by saving energyIf India’s per capita (presently 40 kg) steel consumption is at par with Japan (944 kg), China (400 kg) or USA (330 kg), India would consume nearly 4,500 MW (3 per cent of Indian grid) from national grid for arc-welding process.“Chalta hai, chalne do” is a common practice. Unfortunately, it can lead anyone losing his or her money today. The good old rugged welding transformers and rectifiers may have stood the test of time. However, with the rising energy costs, these equipment can be termed as energy guzzlers when compared to today’s inverter-based welding equipment and the advantages it offers.Inverter-based power sources provide many benefits that can help increase deposition rates, decrease training time, and reduce weld defects and rework time. The inverter-based power sources can payback their costs within a year or so based on utility only by virtue of saving through energy and reduced rework.Why does the inverter consume less power than traditional equipment?Traditional welding equipment were based on transformer/rectifier technology which reduces the incoming AC voltage to weldable voltage levels via a transformer. This cannot operate at more than 65 to 70 per cent efficiency. Also, the efficiency varies across different current levels.However, the welding inverter technology converts the incoming AC to DC and then regulates the DC to give excellent welding characteristics along with an efficiency of over 85 per cent. Performance tests by independent consultants consistently confirm that replacing an old power source with an energy-efficient inverter provides a proven return on investment. Quality of power: power factorEfficiency is only part of the savings equation. Equipment’s power factor also affects one’s energy usage. Power factor is defined as the ratio of real (working) power to apparent (total) power. In a purely resistive circuit, voltage and current waveforms are in phase, and the ratio of real power to apparent power is near to, or equal to one. In circuits with inductors and capacitors, the amp and voltage waveforms are out of phase, and not all of the power is available to do useful work; some of it is returned to the source. Although the power company charges for the apparent power, people are only receiving the benefits of the real power.A high (close to unity) power factor will not only decrease energy usage, but increase you system capacity. Today’s leading inverters, such as SigmaWeld Welding power sources, offer power factors of 0.95.Today state electricity boards have bonus clauses for power factors of over 0.92 and penalties for poor power factors (typically below 0.9)So in the same facility where 20 Welding transformers or rectifiers are being used, more than 40 welding inverters can be safely installed without changing the incoming load wiring or applying for additional connected load (power). This helps grow faster at lower costs. When working on project sites mobility of equipment does not require additional facilities like hydra, cranes etc., welding inverters can be easily portable from one location to another. Also on the same genset, more number of welding inverters can be used as compared to transformers or rectifiers.Consistent performance under power fluctuationsTraditional power sources are tied directly to the input power, which means that a spike or dip in the power supply (such as when a large motor starts) can directly affect weld quality. This can lead to costly weld defects, which may need to be reworked, or cause the part to be scrapped costing time and money, which could better be spent elsewhere.Inverters, on the other hand, are much better suited to managing primary power fluctuations and better suited to handling a variety of power input. SigmaWeld welding inverters can keep welding output constant even if input power varies by +/- 15 per cent. This helps ensure that weld output remains consistent, improving weld quality.Better qualitySigmaWeld inverters also provide other advantages. Welders enjoy welding with them. The consistent arc starts, smooth and stable arc and improved puddle control make welding easier and often lead to better bead quality. With micro controlled-based systems, it is easily possible to incorporate better control features which help reduce dependency on skilled manpower. This allows the operator to concentrate on welding technique. With a welder shortage that is only expected to grow in coming years, features such as anti-stick and in-built hot start have shown to make it easier to train non-welders to produce quality welds. Energy audits at worksSigmaWeld has conducted energy audits at various plants across India. It is found that an average of 30-60 per cent energy savings is possible by converting to SigmaWeld welding inverters from traditional thyristors or transformers. As per the trials, it was shown that if the arcing time per day is assumed at 10 hours and 2 hours of idle time, SigmaWeld welding inverters save almost 35 units of energy per machine per day. This results in an average of 300 (working days) x 35 (units saved) = 10,500 units of energy annually. At the current energy cost per unit, this can save up to Rs 73,500 per machine per year. These trials were conducted vis-a-vis the traditional machines at their works. Similar trials done with SigmaWeld SAW 1,000 Amps welding inverter the customer has saved close to Rs 5,00,000 annually, thanks to their continual production needs.SigmaWeld can also arrange for demonstration and energy audits at clients’ works.SigmaWeld welding inverters operate so efficiently that they easily create payback within 1-3 years. They produce high-quality weld beads consistently, reduce rework and are light enough to move around with great ease. Electronics Devices Worldwide Pvt. Ltd. is a leading manufacturer of inverter-based machinery since 1974. The company is a brand leader in induction cap sealing, induction heating machines, die-electric pre-heaters, SigmaWeld welding inverters for arc, TIG, MIG, saw and welding automation solutions.SigmaWeld welding inverters are 100 per cent indigenously designed, developed and manufactured by its own R&D team. Even PCBs are developed, designed and manufactured in-house. This ensures that SigmaWeld is able to provide prompt after-sales service as well as immediate supply of spares including PCBs. In fact, SigmaWeld is able to provide customisation.Continuing with the energy-saving power sources, SigmaWeld is happy to launch its SigmaTherm induction heater for welding preheating and post weld heat treatment with specially designed PLC interface for P91, P22 and other materials. It comes complete with temperature programming, temperature logging and audio/visual alarms.