Hello, I am posting for the first time. With the help of a friend, I set out to repair a Lincoln Invertec v250-s MMA machine. The problem was created by a welding machine maintenance center
When the station is turned on, it blows the lead regardless of the value of the circuit breaker (16, 20 or 36A), I'm in Belgium. It does this twice and on the third attempt the station turns on. When it is on, it welds. We understood that this was coming from the capacitor pre-charge circuit. One of the relays was welded inside (I put a photo).
We replaced it with a relay of the same value and we also replaced the two resistors of the precharge circuit (20ohm 10W). I am posting an image of the electronic schematic with the part of the pre-charge circuit circled in blue. Following this repair, the station was switched on once without any problem. On the other hand the second time, the problem reappeared, the station blew the electrical circuit breaker of the room twice before starting normally. We reopened the machine and took measures and it turns out that the two resistors are dead. Is it possible to replace these resistors with resistors of greater value even if this is not what was originally there? Or does this failure mean that there is a faulty component upstream or downstream? If so, where to look? Thank you all for your advice and advice!
When the station is turned on, it blows the lead regardless of the value of the circuit breaker (16, 20 or 36A), I'm in Belgium. It does this twice and on the third attempt the station turns on. When it is on, it welds. We understood that this was coming from the capacitor pre-charge circuit. One of the relays was welded inside (I put a photo).
We replaced it with a relay of the same value and we also replaced the two resistors of the precharge circuit (20ohm 10W). I am posting an image of the electronic schematic with the part of the pre-charge circuit circled in blue. Following this repair, the station was switched on once without any problem. On the other hand the second time, the problem reappeared, the station blew the electrical circuit breaker of the room twice before starting normally. We reopened the machine and took measures and it turns out that the two resistors are dead. Is it possible to replace these resistors with resistors of greater value even if this is not what was originally there? Or does this failure mean that there is a faulty component upstream or downstream? If so, where to look? Thank you all for your advice and advice!