Invertec v-205 ac-dc capacitors

[Nederlands]

Hello,

I posted this in,

M

Thread 'Repair Lincoln V205T AC\DC Main IGBT Inverter Board'

Mar 9, 2020

Hi, after long time later, just start again try to repair my roasted main pcb ( called by Lincoln Main IGBT Inverter Board ) of Lincoln İnvertec V205T AC/DC welding machine. I want to try to share my knowledge and experience. First off all i need to circuit diagram roasted section of pcb which is called UPFR section. Many times searched to internet and can not find any information of correct version of this machine. And decide to draw scematic diagram of this section. I hope that if somebody need it and help out this circuit diagram. Also hoping that more people contribute and develop...

• Mustafz
• Replies: 67
• forum: Miller, Lincoln, Hobart

• 

Already
hoping someone can tell me more

Found multible capaciters that are burnded
They are yellow en i didnt see the discolering the first dozen times

C58 was in this topic (1uf 1000v)
Can anyone tell me what the others are?
So i can order these.

Numbers are
C58
C68
C69
C42
C29
C32 there are 2 together but cant read the number
C184
C128

Look at the picture fore there position

• 

 

[Nederlands]

They all look like this one

 

[Seadog]

They don't look damaged. Maybe it's just dust on them.
Usually. that type will go pop and it'll be pretty obvious that they've failed.

 

[Nederlands]

Thanks Seadog,


Its not dust
Tryed te clean them and it wont come off
And cant read the print

But what do i know ( i'm onley a mechanic)

I tested one of them and it was broken(c58)
And seen one with a crack at the bottem

Maybe have to test all of them?

But dont know wat they are exact.

 

[Seadog]

If there's any sign of cracking then they're duff.
They look to me like ceramic capacitors. They're not usually of a very high value and are used for decoupling ( reduction of noise in the circuit).

 

[Nederlands]

The one if found here (c58)
Is 1nf 1000v

Here are some other picters
Of 2capacitors

Trying to read these now
The numbers on these 2 seem the same

But the lack off knowledge makes me search alot.

 

[Seadog]

The likelihood is that they're all of the same value.
A search for "1nf 1000v ceramic" will bring up dozens of hits.

 

[voipio]

The cracks in the capacitors visible in posting #6 are in the encapsulating material, which is quite brittle, and it's not unusual for the encapsulation over the legs to crack. It's not a sign of damage to the capacitor itself.

 

[Nederlands]

Seadog thanx
These 2 in the picture are 022 and below letter L i think

Voipio thanx
i did not know that.

Would it be possible if one or 2 are defective
That it would cause a short circuit?

Welder wont go on at this time
Trips the breaker of te house immediatley

I did replace 6 igbt's

And 3diodes that were defective

And checked the relais

But stil shorts

 

[Seadog]

It's unlikely that they're the cause of the tripping.
However, the only sure way is to test/replace every one. They're not expensive.

 

[6ply]

Thanks Seadog,


Its not dust
Tryed te clean them and it wont come off
And cant read the print

But what do i know ( i'm onley a mechanic)

I tested one of them and it was broken(c58)
And seen one with a crack at the bottem

Maybe have to test all of them?

But dont know wat they are exact.

How are you testing them? Are you removing at least one lead from the circuit and using a capacitance meter?

 

[eddie49]

As others have said, it is very unlikely that these tiny decoupling capacitors are causing a short circuit in a part of the welder that is drawing enough current to trip the supply circuit breaker. If that level of current reached one of these capacitors it would blow it apart.
I have updated the original Lincoln V205T thread about short-circuits.

 

[Nederlands]

Seadog thanx,

6ply
Yes the one i tested ,
Removed first and with my multiemeter tested capacitance
Got around 1800 uf (should be 1nf 1000v)

Eddie49 thanx

 

[Nederlands]

Thanx for the help everyone,

This is way harder than my knowledge allows
And would need extra tools to,
that i'm not able to handle correct.

So i decided to scrap it
And buy a new tig welder

Anyone interested in parts of this invertec?