Trailblazer 250G

[Rjb71]

Hi, i have this trailblazer ser # KG087836 that keeps burning the Exciter fuse F1 in manual. This unit has done this since new, if you have on more than 50 ft of leads. 50ft ground plus 50ft positive cable.Have only every used this to stick weld and the unit currently has 350 hours on it. I have used other units identical to this with way longer leads with no issues. I have tried heavier cable with no success. I figured i would ask before I break down and take it in an pay someone to look at it again. Thanks in advance for any help you can provide.

[cruizer]

Nothing really to do with cable length, F1 guards damage to the exciter windings should there be a problem with SR1 bridge rectifier. And that is where your problem likely is. When a machine comes in with a blown F1 fuse, I always replace the little control bridge

[weldbay]

Nothing really to do with cable length, F1 guards damage to the exciter windings should there be a problem with SR1 bridge rectifier. And that is where your problem likely is. When a machine comes in with a blown F1 fuse, I always replace the little control bridge

Just wondering SR1 is part number 145396 3ph 300A

My schematic shows SR3 in the exciter circiut and it is part number
035704 40A 800V

Is my shcematic wrong for KG087836 or what or is SR1 still causing the problem wiht an overload?

[cruizer]

Nope, wrong again, SR1 is a 25 amp 250 volt bridge.

Again where do you come up with this stuff??

[Rjb71]

Thanks. According to my schematic which I downloaded from this site SR1 145 396 Rectifier Si 3ph 300a. Is this a misprint? SR2 #097 353 is a diode SCR Bridge perhaps this is the one you mean? I would hate to get the wrong part.

[Rjb71]

I see you are in Edmonton, I am in Stony Plain. Where would be the best place to pick up this part?

[weldbay]

Thanks. According to my schematic which I downloaded from this site SR1 145 396 Rectifier Si 3ph 300a. Is this a misprint? Would hate to get the wrong part.

Better contact Cruizer, apparently he knows that the Miller schematic was a misprint by the way Miller recommended that if you were having this problem to contact an autorized service shop.

[duaneb55]

Nope, wrong again, SR1 is a 25 amp 250 volt bridge.

Again where do you come up with this stuff??

Recheck your information Jeff. SR1 is always the main output rectifier designation and the tech manual confirms F1 is teamed up with SR3 on this machine.


Rjb71 - what size fuse you using? Should be 10A and DON'T put a bigger one in unless you want to find the next weaker link.

You're correct on the PN and rating for SR3 but I would be looking at all the connections in the exciter circuit taking a close look at the connections at the rotor brushes. A poor connection causes an increase in current to get the same job done and could be the reason for your blown F1.

[cruizer]

Need a bigger screen, this 43 is cutting it anymore, yes bridge SR3

and yes I have lot of them in stock

[Rjb71]

Recheck your information Jeff. SR1 is always the main output rectifier designation and the tech manual confirms F1 is teamed up with SR3 on this machine.


Rjb71 - what size fuse you using? Should be 10A and DON'T put a bigger one in unless you want to find the next weaker link.

You're correct on the PN and rating for SR3 but I would be looking at all the connections in the exciter circuit taking a close look at the connections at the rotor brushes. A poor connection causes an increase in current to get the same job done and could be the reason for your blown F1.

10 amp 250 v same as what it calls for. Thanks