Good.... I have a machine Esab dta200ac/dc and one of the Tiristores has been shorted... Esab no longer has spare.No what tiristor is.... The reference is GT1726/TH8550, I don’t know if it’s phase angle? -Fast?. It carries four of the same and are the same as dtb200 and dtb250
hi
try google the numbers youwill find a equvent as long volts and current are same or higher you should be ok check the drive is ok to thease divices if it wlii not work
Hola !
The manual for the machine, inc. circuit diagrams, can be downloaded here: https://elektrotanya.com/esab_dta_200_dtb_200_dtb_250.pdf/download.html
The part number on your component looks like IR ( International Rectifier ) G1726/TH. The "85 50" could be a date code - e.g. week 50 of 1985...? Maybe the TH means thyristor. I haven't found any matches for G1726, it may be a vendor-specific number.
The ESAB internal part number is 349 054-001, but as you have said, they don't stock them.
Maybe try: https://www.westermans.com
From the physical size, I would guess it is a component that can handle currents in the 50 to 80 Amp range.
It looks like there are 4 SCRs/thyristors wired as a pulse-controlled bridge rectifier, across the secondary of the main transformer. The trigger pulses driving the thyristor gates are synchronised to the 50Hz frequency of the incoming AC mains, so yes, you could call it a Phase Angle Control circuit. I think that the secondary voltage is 135v.
This component might do the job: https://www.ebay.es/itm/Tiristor-de-control-de-Fase-de-Perno-SCR-100A-1600V-KP100A-E6Q2/183625954437
The ST230C04 is a very large thyristor, 400V and 410 Amps, in the "puck" flat-case style. One of these thyristors is used in the machine. It is used in DC mode, with 2 of the smaller stud-type thyristors. In AC mode, only the 4 stud-type are used, as a controlled bridge.
I'm not sure why you are mentioning this "puck" device, I thought that you had already identified the fault as a short-circuit in one stud-type thyristor?
Hello, the tiristor is ST200C04C.... this tiristor works well. is wrong one of the other four.... my question was whether you are sure that the other four are phase angle?thankyou
Basically, a thyristor is a thyristor. It's the same part, regardless of what you use it for ( although some devices may be particularly suitable for a certain circuit or application ).
In this welder, the four G1726/TH thyristors are wired in a 4-diode bridge, like a normal rectifier, across the AC output of the secondary of the main transformer. The thyristors will only conduct when their gates are triggered on, and they will stop conducting when the sinusoidal AC waveform crosses zero volts, for both the positive-going and the negative halves of the sine wave. The effective power passed to the load will therefore depend on how far from the start of each half-cycle of the AC waveform the trigger pulse is applied. This is known as the phase angle. To stay in-phase, the pulse driver circuits are synchronised to the 50Hz AC mains.
Since Forum member Bobbes has identified the thyristor as a 230 Amp device, I have obviously underestimated the physical size of the part. The part that I suggested from eBay.es is too small - it's only 100A, the correct part has to have a much higher rating.
On the original thyristors, are the studs ( nuts ) really 3/4"-16 UNF - - about M20 ?? That's impressive!
hello are so.... much bigger than the ones that had...twice as much, I’ll look at the relays to see something weird flash...capacitor?,The cards checked and were fine
The fith thyristor on the top, that round model, has the problem that after many years they need more trigger current then the PC board can give. In that case you have to change the big thyristor on the top.
5 tyristores new.....it doesn't
in the absence of putting the capacitors
it does the same, I test it with an electrode and it sizzles in mma and in tig ...... in ac and in dc.The high frequency starts to work without pressing the button of the tig hose,
If I disconnect the disk thyristor sizzles only in DC .....
[QUOTE = "eddie49, post: 1311722, miembro: 5926"] ¿Se comporta la máquina de la misma manera (corriente demasiado baja) en AC así como en DC? [/ QUOTE]
Yes...un ac and dc....in tig and mma.
OKé that is a clear problem. The relais of the 4 takt stroke is activated. Follow this instructions very precisly. The knopes pre- and posttime on zero. The knopes Up- and downslope to. Switch off the machine. The switch 4 stroke 2 stroke in the position 4 stroke. Switch on the machine. Activate the torch button just one time. Switch now the machine in the position 2 stroke and if everything is oke the machine works fine. If not the relais 4 / 2 stroke is broken. The relais is mounted on the inside of the frontpanel somewere on the top.