Termal Arc Predator TA-10/270 H Low Output Voltage

[duaneb55]

Had the above machine come in last week with a low auxiliary output voltage complaint. Engine speed/frequency was an acceptable +/-62HZ but VAC at the 120V receptacles was +/-87V. The Predator 3-phase generator is a brushless, capacitor regulated design so its bank of 3 tri-capacitors was suspect. This suspicion was supported by a bulge in the upper visible unit and once the bank was finally pulled from the chassis it was confirmed. 2 of the 3 cooked with their bottoms blown out.




Best price I found for new ones made in Italy was at Airgas for $139 each x3 plus tax and shipping. Even though 1 checked out OK they all got replaced as is my normal practice.




Once coupled together with 3 buss bars and the covers installed they get stuffed down in this hole which is a little tricky but definitely doable.






Thanks for looking.

[duaneb55]

Actually, the unit is a "Power Plus" but the manual is listed as "Predator".

Same model TA-10/270 H.

[MinnesotaDave]

That's pretty interesting.

[duaneb55]

Seen a couple around but this was the first Thermal Arc engine drive I've had to work on. This one is Honda powered but Kohler was used as well.

Weld Fine V/A control is simply by throttle adjustment with wide open for auxiliary power output for proper frequency of course.


Forgot to add that following the capacitor replacement auxiliary power output was still +/- 62Hz but now +/-120VAC with CC weld OCV at 98VDC (spec is 100V).

[mla2ofus]

Any thought about what caused the failure?
Mike

[duaneb55]

Just tired capacitors. See it all the time with capacitor regulated generators. As with batteries, capacitors have a finite life. Some a little shorter/longer than others.

[12V71]

I had one of those early Predators bought in '99 or'00, it was an ok machine for a mechanics truck. Later bought one of the last of the DC weld only Models and it wasn't a bad machine. I never really got the arc force control on the later one figured out. I got the first one for the 480 3 phase output to move center pivot irrigation machines before the power was connected.