A reversing switch is also known as ‘Polarity reversing switch’ has four terminals that can be connected in pairs in two different directions to reverse the direction of the flow of current. There are different types of polarity reversing switches that are used for different applications.
One of the most common applications of this switch is seen in electric trains where the voltage is reversed that causes a change in the direction of the train to move in the opposite direction. It is made using a double pole double throw switch. Let us take an example where we take two wires.
So, when the electrode is connected to the positive terminal while the workpiece is connected to the negative terminal, then it is termed as ‘Reverse Polarity’ or ‘Direct Current Electrode Positive’ (DCEP).
Generally, when there is damage in a massive power plant boiler, repairing it can last for months or even years and this can be maintained by using a strict timeline and follow guidelines. Let us now talk about an incident that took place at NAES Power Contractors in Cranberry, Pennsylvania.
They had an issue and had to run repairs on the inner tubing of the plant. This caused a replacement of 50 to 100 people who work on contracts in the boiler plant wall panels. These workers had two shifts for 6 days a week.
It is based on the size and difficulty to reach each boiler part in the plant that makes the job tedious and time-consuming. The welders had to first climb a 24 x 24 hole and then crawl further into the pipeline area for them to be repaired.
No matter how hard it is to reach and work at a particular place in the boiler plant, the finishing and repair works must be on-point and of high-quality standards. This company generally deals with and repairs a lot of SA213 T11 material, which is a 1 ¼ chrome-built boiler tube that could have thicknesses to about 1 ½ inch.
They perform ‘Gas Tungsten Arc Welding’ (GTAW) which requires an arc electrode and a lot of shielding gas to facilitate the welding process. They also use ‘Shielding Metal Arc Welding’ (SMAW) in some cases.
Nowadays with the improvement in the variety and functionality of reverse polarity switches like the ‘XMT350 Field Pro’ that was manufactured by the ‘Miller Electrical Mfg. LLC’ which saves a ton of time for this welder as it has a single switch that can easily reverse the polarity.
This is the image of the Miller ‘XMT 350 Field Pro’ polarity reversing switch unit.
Sean Coby is a welder par excellence and well respected among the welding community in Woodbridge, VA. He prides himself to be the fabricator and mechanic in the automotive/ diesel industry for the past more than eight years now. As the chief editor of his https://weldinginfocenter.com, he shares his experience to be safe during welding and to take proactive steps for becoming a successful welder like him.