How do I find out how much heat is generated by a spot welder?

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How do I determine how much heat is generated by a spot welder. Specifically a Teledyne Peer 50 KVA and 75 KVA. I am trying to determine the heat load in order to calculate the amount of air conditioning need to cool a manufacturing plant.

-- Chris Ganshert (chris_ganshert@tciltd.com), September 28, 2000

Answers

Response to how do I find out how much heat is generated by a spot welder

Chris , The heat radiated from a resistance welder will be relative to the heat generated inside the unit and allowed to remain there. Your most efficient cooling , regarding the machine , will be the chiller that is serving the welder itself ( keeping it cool internally ). To determine the amount of cooling necessary to cool the welder internally use this formula. Measure the temperature of the water going into the welder. Measure the temperature of the water going out of the welder. Measure the amount of water flowing through the welder (gal. per min.) Armed with that information you can now determine the amuont of BTU's necessary to cool the welder , by using the formula. Multiply 500 (which is a constant)by the gallons per minute (that you measured earlier). Then multiply that answer by the temperature differential that you measured (between inlet and outlet water). Example: inlet water temp.= 60 degrees outlet water temp.= 72 degrees gallons per minute = 10 gal. 500 x 10 = 5000 5000 x 12 = 60,000 60,000BTU's / 12,000BTU's (one ton of cooling) equals 5 tons of cooling. To be less precise , a rule of thumb is one ton of cooling for each 100 KVA of welder rating. Now this is strictly a personal guess and not scientific , however , I would expect that the radiated heat from a welder is about 25% of the internal heat generated within the unit. Next , you need to consider the heat generated by the parts being welded , because the welded parts will , probably , radiate more heat than the welder. Aluminum parts will generate less radiated heat , of course , than steel parts. It's not uncommon to be able to pick up a welded part immediately as it comes out of the welder , but a minute later you can't stand to touch it. It is my opinion that the heat , from the parts , must be considered by noncontact measurement of the heat being produced by the process in realtime. I hope this was of some benefit , good luck.

-- Bill Lucas (welders@tjsnow.com), September 29, 2000.

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