Spot welding going wrong (again)

RikH

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Joined
Nov 22, 2018
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87
Hello all,

Cause of some videos on YT I'm now way over enthusiastic about this DIY powerwall thing. It has costed me tons of time to watch them all. Besides that I'm afraid I got infected with this battery virus thing. I don't want to mention the guilty for this all but there names start with H, D and A and they end with HBPowerwall, DIYtechandrepair and Average Joe.

SoI bought a spotwelder on Ali to start practicing my skills but it doesn't work as it should. It makes a few (4 to 6 or so) welds and then the next one gives a big bang with spark and all and the fuse trips. When I try immediately after resetting the fuse it will trip again but when I try next day I can do a few welds again before fuse trips. What can this be?

This is the welder I purchased:

Spot welder

I asked the supplier and he just answered to put a 40A fuse which is easier said than done cause the main fuses in my house are only 25A and the subsequent is 16A. Here in the Netherlands, we have 230V mains so the man is telling me I should fuse for a burst of 40 x 230 = 9.3 kW which sounds ridiculous to me.

What are your thoughts on this?

Rik
 
It looks like you bought a cheap welder that doesn't even have a brand name. I would return it and buy either a Sunkko 709AD (220 version) or a Kweld. It is normal for the welder to draw a high instantaneous current, but there's no way it should require a 40A breaker... I have 15A fuses on my Sunkko and have done tens of thousands of welds without ever blowing a fuse.
 
I agree with mike. It shouldn't be popping the breaker/fuse like that. Something is wrong with it. I wonder if the transformer is wound properly with the correct winding count.

At that price range, I think you can get the same type of welder Peter/Joe use. But the Kweld is also a good option and it'll run off of your DC power supply (whether thats solar generated battery stored, or power supply)
 
Hi Mike,

Tnx for your response. I was afraid for this answer already, I should'n have bought it. I was already looking at the 709AD but there is also a 709AD+ version. Would that one be better?

Rik


Korishan tnx for your advice. Can the Kweld be bought complete or do you have to make it yourself? I prefer an out of the box working solution. Do you have a link to the Kweld?

Regards, Rik
 
RikH said:
I asked the supplier and he just answered to put a 40A fuse which is easier said than done cause the main fuses in my house are only 25A and the subsequent is 16A. Here in the Netherlands we have 230V mains so the man is telling me I should fuse for a burst of 40 x 230 = 9.3 kW which sounds ridiculous to me.

What are your thoughts on this?

The supplier is correct, the power requirement is one of the few specifications listed in that link you posted.

Can you confirm that your property is limited to a total instantaneous demand of 25A or is that simply the fusing on the circuit the welder is connected to ?

25A for an entire house is very low.
 
Hi Sean,

Yes the average household connection over here 3 x 25A. After this fuses comes the meter, all sealed. AFter this you have your own fuse for several groups in the house wich are fused 16A. 16 x 230 = 3,6 kW. When you need more you need 3 phase equipment but thats not what this welder is. But you're right it is stated clear that it is 10 kVA.

So if anyone can use this thing give me a pm.

Ciao, Rik
 
3x 25A sounds more useful - but not for 1ph spot welders :-(

If you've got a good quality 25m mains extension cable (or longer) you might have some joy plugging your welder into that.
 
RikH said:
Hi Sean,

Yes the average household connection over here 3 x 25A. After this fuses comes the meter, all sealed. AFter this you have your own fuse for several groups in the house wich are fused 16A. 16 x 230 = 3,6 kW. When you need more you need 3 phase equipment but thats not what this welder is. But you're right it is stated clear that it is 10 kVA.

So if anyone can use this thing give me a pm.

Ciao, Rik

hello rik.

i find it hard to believe that you need that kind of power.
i think for now you have two options

1 ) check your automatic breaker , is it a 16A B then you can change it for a 16A C , the C breaker can withstand a higher inrush current , mostly used when you use heavy equipment like grinders , welders etc..

2 ) when you are good in electronics you could check how the welder is build up and maybe you could change the active element by a solid state relais , the most have a zero crossing function , this is a much better switching and can prevent the tripping of the breaker.
i have build myself a spotwelder and a 1000 Watt microwave transformer in conjunction with a ssr and i have no troubles what so ever

also the tip from sean : If you've got a good quality 25m mains extension cable (or longer) you might have some joy plugging your welder into that , it works like a gigant inductor and so this could be the solution
that would work for you
 
Before you buy another welder, replace those probe cables, they look like copper clad audio wire. You need to get 6 gauge pure copper welding cable (you can get about 3 feetblack/red cable on ebay for less then 20 dollars.

With pure copper you can reduce the power setting on your welder. If the setting is too high you be blowing fuses and the cheap copper clad cable will be getting hot. I would try that before spending 200 dollars on another welder, which might keep blowing fuses.

My advice since you might have problems with your house current is to buy a battery powered welder, the malectrics cost 100 dollars and is rock solid, you can run it off a 12 volt car battery or even a 3s lipo battery pack. I build many packs with one of them.

I got the first version they sold, below is a picture of their version 3 which is a big improvement but the old version worked great also. This welder fits in the palm of your hand but is comparable in power to any of the plug in models.I weld in power setting 3and it goes all the way to 9.

image_icatds.jpg
 
Ok, I decided to go this way: try a long extension cable and if that doesn't work I'll buy the welder jonyjoe505 pointed me to:

Malelectrics

Leipi35 tnx for your kind advice in changing fuses, cables etc but I don't want to to to much time and effort in this. Tnx to all so far, I'll let you know if the test with the extension cable will solve it.
 
Myself is using 16A slow breaker C rated and it works fine here. Its on the edge to burn off doing many welds in row on max settings but it works

Its alot of difference between C style and B style as said.
 
So after a while, we bought a new house, I went on with the spotwelding. There is a Malectrics now and it seems to do quit well but sometimes the positive probe sticks to the nickel and it won't weld to the battery and that becomes worse all the time.



image_wnakzg.jpg


image_lvzbsp.jpg


First I've changed the welding wires for the thick copper cables that I took of the shitty chinese welder.


image_jwnfis.jpg


image_hiohhl.jpg


Also tried to fiddle with the settings but it doesn't seem to make a difference if I choose 5 or 15 ms. And yes it is set to manual.


image_ffjrmv.jpg


A lot of welds are going well:


image_pqawmj.jpg


What am I doing wrong??

Any help appreciated!


While I wait for some advice I'll try to weld some fuses and post the results here later. Details of the pack build will follow in another thread.
 
Sound more like the welder is doing something bad internally on weld #5 or #6 when you get the big spark.
Probably this welders control circuit is shorting/staying ON not just doing the normal short burst.

You usually spend one or the other! time or money & sometimes both ;-)
 
I built a spot welder out of a 12V battery, car solenoid, welding cables and chinese timer. It works but was not elegant and I wanted more control over the current for the spot weld. I recently bought a Kweld and so far so good at this point with just some minor use. I can report more later after I embark on a bigger powerwall project with it.
 
Is there also the possibility that the car battery is to strong? The battery 680 CCA and was brand new nut not fully charged when I started. While welding it was on a charger and became worse and worse. I tried to weld 2 fuses but that gave a spark like lightning. Great balls of fire!!


image_kknlpp.jpg


image_dpxssg.jpg


Will try another battery and post results.
 
clean the cells and nickelstripes before you spotweld them with isopropanole

and please charge the battery full before you use it
 
Like said above, that spark is from bad contact with the material you're welding.
You have to press down firmly & have clean surfaces (both nickel & cell).
Use the better (black) leads with the heavier tips, they will make better contact & not heat so much themselves.

Are you welding fuses to the cell +ve in the pic with the flash? Maybe you should position the +ve busbar first, otherwise the possibility for sort circuits is high!
 
PAF: Ok, I'll try to get my hands on some.

Redpacket: Yes I weld the fuse direct to the + side on the battery. On the - side is a nickelstrip for balancing purposes. I'll put the original black cables back because of the better tip.

This is the answer I got from Malectrics:

Hi,
Its hard to tell what could cause your problem.
Maybe a problem with the welding cables giving bad contact.
The problem could also be welding the fuse wire to the nickel strip / battery. If this has only little contact to the nickel strips it can produce very big sparks.
You could try to use a smaller car battery to get less current and increase the weld time.
Maybe welding the fuse wire works better with lower current and longer weld times.

I'm gonna try all this and report back. Thanks guys!
 
And now it works like a charm! Look at this:


image_zhzjyc.jpg


Isn't that a good weld?

Changed battery for a 440 CCA and increased the time to 30 ms. Cleaned everything with contact sparay, put the original wires back on and there we go. I'm happy now.

Thanks for all your answers gentlemen!
 
RikH said:
And now it works like a charm! Look at this:


image_zhzjyc.jpg


Isn't that a good weld?

Changed battery for a 440 CCA and increased the time to 30 ms. Cleaned everything with contact sparay, put the original wires back on and there we go. I'm happy now.

Thanks for all your answers gentlemen!

I am a little confused about the picture.
The cells on the right have only the nickle strip while the ones on the left are fused?
 
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