IF the device has that DC feature.  I am guessing it is just an AC output with heavy duty variable tap transformer and contactor with a timer.

 

Hey ya'll, watch dis!

Not sure what to make of y'all's info. I am pretty ignorant about this subject. 

Also, I notice that the "same" unit has a very different label in the Youtube video previously referenced:

So, 2.5kVA?  What does Sn stand for?

Another reason I'd like to understand this better is so I could compare this unit to this one, for example:

https://www.harborfreight.com/240v-spot-welder-61206.html

So, $160 vs. $649...  And the cheap one has 2.5 kVA in the specs.  Not sure any of the labels are going to be trustworthy?  

Is inverter technology anything to warrant discussing?

 

 

Edited February 6, 20205 yr by inline6

The "inverter technology" means that it's more complicated than a AC output with heavy duty variable tap transformer and contactor with a timer.

The variable tap transformer stuff is heavy and contains a lot of copper. The inverter stuff is light and contains a lot of electronics.

I don't know what "Sn" means, nor do I know how to interpret the goofy numbers on the spec sheets. From what I've heard (from people who supposedly know such things(, welders are one of the prime candidates for "specsmanship". The specs are often convoluted, misleading, and highly dependent on lots of variables and how the unit is used. Fine print and all that.

20 hours ago, Captain Obvious said:

The specs are often convoluted, misleading, and highly dependent on lots of variables and how the unit is used. Fine print and all that.

Yeah... definitely getting that sense at this point.

Edited February 7, 20205 yr by inline6

Since you're not planning to use this in a professional every day heavy use application, my recommendation would be to use reviews instead of specs to compare.

I suspect the big difference between welders is the duty cycle. And you probably won't be taxing the limits.

11 hours ago, Captain Obvious said:

my recommendation would be to use reviews instead of specs to compare.

I'm inclined to agree.  It can be really challenging to translate engineering specs into real-world outcomes. 

However, some of us like playing with numbers, so...

The duty cycle (%) means that the machine can sustain the stated power output for x% of the time.  If the machine is rated as 1.6kVA with a 50% duty cycle, it means that it can produce a stated output of 1.6kVA for, say, 2 seconds, provided that it gets a 2-second dwell time before the next actuation.  Or at least, that's the way you'd interpret it for a MIG welder, where the operation tends to be somewhat sustained (as in running a 1/2"-long bead).  However, for a spot welder it's a little different.  Here, the normal electrical operating mode (selected by the operator, but controlled by the machine) is a continuous and rapid on-off cycling (1 time unit 'ON' followed by 1 time unit 'OFF' = 50% duty cycle).  For reference, notice the 'square wave' icon next to the green indicator light on the machine shown in the video.  

So: the 'n' in 'Sn' means 'normale'.  This is written as 'conventional power' on British-spec welders.  Probably stated as 'regular operating power' or 'regular duty cycle' in North America. 

I do not know what the 'p' in 'Sp' means for your machine, other than the fact that it's probably tied to the 'I2p' current rating.

I do know that 'I2 cc' refers to the machine's closed-circuit (or 'short-circuit') current rating.

I looked at the PDF spec and it too says ~6000 amps... the company seems solid so I wonder how a typo got into two docs?

I don't think it's a typo. I think there's a way to interpret that spec that makes it "correct".

The 2.5 Volt welding voltage is probably the open circuit voltage at the electrodes. Problem with converting that to a simple KVA rating, however, is that as soon as the electrodes are closed, you don't have 2.5 Volts anymore. You'll have something less.

The 6000 Amp max welding current is probably a very short burst of current that occurs for a tiny instant of time when the electrodes are first connected. The "realistic" welding current is probably something much lower than that.

The "rated power" is probably an averaged rating of how much power it draws under "normal circumstances". At 180 spots per hour, you're doing 3 per minute. If it takes ten seconds to position and ten seconds to weld, you've got a 50% duty cycle. My guess is you're drawing an ave of 2.3KW under those conditions.

And something else thing to remember... The electronics inside the device consume power too. It's not all presented at the electrode tips. Some of the power consumed from the line cord goes into powering the device itself. It'll get hot inside and that power came from the same cord. So it may draw 500W quiescent power when just idling between welds. No idea.

According to the label, that spot welder is made by Telwin. They are Italian (we already knew that).

Web page here showing their products (prodotti)  >>  https://www.telwin.com/en/prodotti

That welder is their Modular 230 (or an earlier version of the same), and if you dig down into that model, you can get to a datasheet. Here's some info from the datasheet that may help with the above academic discussion:

 

 

 

Enjoy.

 

Great find.  Thanks for sharing!