i mail them last week but they didnt respont,i just bought the machine broken last week & until it get repaired i want to lern how it works
if someone has an advice for repair or the service manual ,will be nice to help
the rectifier was sorted & after i change it 1 of the igbt's died also,the machine was half repaired again (igbt problem) without the original component
For one reason or another Weco are not a brand that we see much in the UK. Maybe that explains the lack of responses.
Service manuals and cct diagrams for inverters are not things that the makers seem to hand out freely. Maybe it's because repairing inverters is potentially fatal and they don't encourage everyone to have a go.
When you get a service manual, the best give a block diagram and circuit description as well as the circuit diagrams and scope traces of the signals driving the IGBTs. They leave a lot of the detailed fault finding to the person reading the manual and the assumption seems to be that most people will be happy to do a board swap, not repair to component level.
Modern inverters are microprocessor controlled and if there's a problem with that, it's another level of complexity.
The Weco website has a reserved area which you can apply for a user name and password for. Maybe the service manuals are there. See the top right hand corner of their home page.
Generally if you are thinking about buying something faulty with a view to repairing it, it's best to make sure you can get the service manual before you part with the money, or it has to be so cheap that you don't care.
i dont think that i need the service manual( nice to have it) but the owner manual that should be free (in my opinion)at weco site.we live in 2012 i think that thinks like that cost nothing for the company & give bonus & sales from nothing
Maybe they should put the owner's manual on their website, but in my experience owner's manuals are all much the same and of little or no use in repairing an inverter. If they go into any sort of technical deatail, it's at the level of mains lead, switch, PCB, overheat LED, welding output terminals. There may be a diagram of the internals which doesn't tell you much more and nothing which isn't fairly obvious; capacitors, heatsinks, IGBTs, output diodes, choke, main transformer.
You could as well take an owner's manual for a similar machine from a different maker. The specification is in their catalogue and marked on the machine.
Hi all!
They have it at their website. You only have to regist your self. I mean, the only have the owner manual. I already saw it and it has a simple block diagram of the 150TP model.
Mine, doesn't start. Only turns on but power relay doesn't energises! Any idea?!
The way inverters work is to rectify the mains to charge up several big (usually three 470µf) capacitors to 340V or so. The charge on the capacitors is then switched about 25,000 times second by electronics into a step down transformer to produce the welding current. There's a feedback loop to keep the output current to what you set on the dial.
They need a low voltage supply (about 12V) to power the electronics and the fan. This is usually produced fron the charge on the main capacitors by a chip which switches the charge through a small transformer the output of which is regulated to produce 12 volts.
There's another problem. if you connect the capacitors through a rectifier to the mains, you will have a current surge of 100s of amps for a fraction of a second. A current surge like that could throw a trip or cause problems for components in the inverter. What's usually done is to charge the capacitors fairly slowly (about a second) through a resistor or thermistor. When the electronics detect they are fully charged, it activates the relay to short out the resistor or thermistor and you can start welding.
Usually you switch on the supply to the inverter and can hear the relay click on very shortly afterwards. When you switch it off the fan keeps going for a few seconds from the charge on the capacitors, then you hear the relay click off.
In this case;
the slow start resistor or thermistor could be burnt out
there could be a dry solder joint
the rectifier could be faulty
the chip or other parts producing the 12V to power the electronics and power the relay could have failed. Does the fan work? I assume it's a 12V fan and not powered direct from the mains
the relay could be faulty, either the coil burnt out or a mechanical fault
The electronics might be acting up because of a short caused by metal dust
It's hard to say without seeing the inverter and having a circuit diagram, but you might be able to fix it by checking some of these things.
Be very careful working on this. Under fault conditions, the big capacitors can hold enough charge to kill for a long time.
if the display works 12v is probably fine,if you have a multimeter check the rectifier, if its faulty its not just the rectifier probably some of the igbt's are faulty too before try to change ALL OF THEM if faulty measure the driver circuit too zeners & tranjistors may be dead too