SIP Mig mate fuse blowing when trigger pressed.

[skotl]

I'm not familiar with this model, specifically, but you may also come across a bridge rectifier, which is a single (normally square, black) package containing four diodes.

It has two x ~AC inputs, and a +ve and -ve DC output (in other words, four pins).
Here's a pic;

So, it may be worth looking to see whether your welder has one of these.

 

[JuniorMIG]

Im gonna get my dad to take a look tomorrow as he knows about electronics on a whole new level compared to me but I will look out for this

 

[skotl]

P.S. (and this is not meant to be condascending!) well done on getting into electronics and welding at such a young age.
I was very much into electronics from around age 13 but I only got into welding two years ago, when I was 46!

I work in IT and whether you want to work in electronics, manufacturing, software, fabrication, banking, painting or interior design I think it's great to have a whole bunch of practical skills that you can employ, either professionally or at home.

Good luck with your learning!

 

[JuniorMIG]

Thanks very much, when I was about 13 I wanted to study to become a software developer or PCB designer but after stripping down my first engine last year I realised I love working with my hands

 

[shenion]

I'm not familiar with this model, specifically, but you may also come across a bridge rectifier, which is a single (normally square, black) package containing four diodes.

It has two x ~AC inputs, and a +ve and -ve DC output (in other words, four pins).
Here's a pic;

So, it may be worth looking to see whether your welder has one of these.

That is not the rectifier bridge in question. It may have one, but that is not the problem. The rectifier bridhe is a set of metal plates with diodes usually pressed into them. Usually look something like this:

 

[JuniorMIG]

so yea my dad left for work early so no help till tonight... But im still confused on what actually is wrong could anyone suggest how i can test what is broken. I think the order of how the mig works is switch is pressed, PCB processes it, The smaller transducer powers the relay, the relay acts as a switch from low current circuit to high current, the relay switches to the motor then the motor is connected to rectifier, the rectifier is connected to the larger transducer which goes back to the trigger? im not to sure about this i guess its all a learning curve

 

[rtbcomp]

I've already suggested you test the rectifier diodes with a meter. There are several possible causes of what's happening, you've got to eliminate them one at a time.

Basically when you pull the trigger a relay starts the motor, opens the gas valve (if fitted) and calls a contactor which supplies power to the welding transformer. A smaller transformer is provided to power the motor and relays.

The motor may drive its power entirely from a small transformer/rectifier or from the welding voltage. In both cases a basic electronic circuit is provided to allow speed control of the motor.

It would be impossible to say exactly how your welder works without a circuit diagram.

 

[BrokenBiker]

as above, things need to be done categorically, firstly you need to eliminate the rectifier that rtb has mentioned, then look at the (usually 24V d.c.) smaller transformer that supplies the relay, motor, gas valve etc, then the relay, then the motor.

as mentioned above, when you pull the trigger a few things happen within milliseconds of each other, the relay will energise sending power to the dc wire feed motor and the gas solenoid valve, the main contactor will pull in and allow current from the main welding transformer to flow to either the torch or the return clamp depending on how your welder is set up, via the rectifier shown in the labelled picture.

basically you get (relatively) high voltage/low current ac into the main transformer, and (relatively) low voltage/high current ac out of it that goes to the rectifier, this then rectifies to dc, and then on to the torch or return.

I am only guessing but I would say that the issue is on the ac side of things, or with the rectifier as mentioned above.

have you checked the voltage switches and wire feed pot? I cant see it being anything to do with those but always good to check everything even if you think its not related. my Suzuki bandit died on me and just would not start, ignition worked but nothing when I hit the started. turned out to be a blown indicator bulb that was stopping it starting. for some reason they run the indicators through the ecu, so as soon as one blows it shuts everything down, so its always good to check everything until you find the fault

 

[rtbcomp]

have you checked the voltage switches

Worth checking - there's a remote possiblity that welded contacts could cause part of the primary of the main transformer to be shorted out.

 

[JuniorMIG]

thanks very much my dads multimeter is made by fluke so apparently its top end and can test the welding transformer at its full amp output thanks very much for explaining everything to me im going to sit down tonight and test everything and il post back when I know what is wrong

 

[mike 109444]

This might help
note the highlighted part is the "change over" leads for Gas to Gasless and may not apply is yours is Gas only

 

[BrokenBiker]

thanks very much my dads multimeter is made by fluke so apparently its top end and can test the welding transformer at its full amp output thanks very much for explaining everything to me im going to sit down tonight and test everything and il post back when I know what is wrong

you're getting way ahead of where you need to be looking.

how do you expect to test the welding output current when you blow a fuse every time you pull the trigger.

i have a van full of electrical test equipment, tools and hardware but unless i use it in the right places i may as well be using a cheese grater for all the good it would do.

there is no point testing the welding current until you have figured out why the fuse is blowing, as the welding current will not show on a meter until you can hold the trigger and get it actually working first

 

[JuniorMIG]

brokenbiker, I posted yesterday explaining that the fuse doesnt blow any more to be honest I have no idea whats wrong now

 

[rtbcomp]

Just to clarify - Has the fuse stopped blowing now it's in bits on your desk, or have you put it back together again?

 

[BrokenBiker]

ok, fair enough, but there is still no point testing the output welding current if you haven't got everything else working, in fact i can see no need to test it at all unless the welds are weak and unstable.

so the wire feed motor doesn't work? First, check the + and - on the motor, you should get resistance. Not a great deal, might even come down to continuity level but if you don't have any reading then the motor windings are burnt out. If the motor tests ok, check the connections it leads to on the relay. This can be done two ways, you can either check continuity, should have none with the trigger out and full continuity with the trigger in, or you can use a voltage test. Should have voltage on the meter with the trigger out and no voltage with the trigger in. If this is all ok then test continuity of wires feeding the motor.

if that all checks out then there a few other things to check but ill leave that until its needed

 

[JuniorMIG]

rtb it has been put back together and the fuse doesnt blow but the motor doesnt work?

 

[JuniorMIG]

brokenbiker thats that clears everything up il get back to you if i have success or not

 

[Sean]

rtb it has been put back together and the fuse doesnt blow but the motor doesnt work?

you have put it all back the way it came out Its pretty simple in there but there a a good few Lucar terminals and all the wire seems to be the same colour - i usually mark the terminal and its location with a sharpie ive ruined too may expensive electric things just tearing them down - .sppose its an age /experience thing

 

[JuniorMIG]

Sean I take photos of all connections and some times put a white label if there is no colour code on connections. I have taken things apart and not been able to put them together

 

[BrokenBiker]

to be honest, when fault finding electronic appliances you should keep it all together unless you absolutely have to take it apart to get access. Electronic components suffer from static and this could cause big issues.

i doubt you have anti static equipment, so i would have left everything as it was and tested from contacts. Even if you cant get at a contact on a component you can probably get at the next contact in the line, which will give exactly the sane reading, for instance instead of trying to take a reading from the output pin of a diode, you can take the same reading from the input of the component it leads to. Very little reason to take things apart while fault finding. and it eliminates any chance of putting it back together wrong and really lowers the chance of static build up. You just have to be careful not to bridge any connections and short something like a transistor or 555 chip