1000VA UPS

[Delta Prime]

(And . . . . . LOOK MOM ! . . . . . . . no Snubber resistors or capacitors are even being involved.)

Yeah the capacitor was collateral damage.
But what I find interesting is I've never seen a fuse obliterated like that is was generating some heat ;I mean the solder pads blew off the board.
The board itself carbonized!
I bet when he replaced the output mosfet and install that resistor he turned the unit back on. But that was after the fact.
MOM couldn't see it; she was too busy admiring my snubber.
Even got a MOV.
If I were you I would fill in the component values on the schematic you can probably make some money. I love the component layout architecture on this board.

 

[kellys_eye]

But what I find interesting is I've never seen a fuse obliterated like that

It wasn't a fuse. It was a resistor.

I love the component layout architecture on this board.

C5 is correctly labelled as is R3 - R3 being a ceramic high power device.

 

[Delta Prime]

WHAT ! I see being done, is there was being a production change and the initial F7 fuse being changed to this value of FR1 FUSIBLE resistor.

COME GO WITH ME . . . . . . . AND LETS GO WITH THE FLOW . . . . .

Have you ever seen an fusible resistor FR1 fry like that?

If you lead.... I may not follow.....
If I lead you may not go.....
But I think it is best if we get lost together.....

 

[am.steen]

In fact burned resistor and capacitor related to charging and not affecting normal inverter section of ups.
Today I try ups on 24v and it produces about 150v for 2 sec then stops, and some time there is no output until check output with multimeter then the output comes
please check this video

Any suggestions??

 

[Delta Prime]

In fact burned resistor and capacitor related to charging and not affecting normal inverter section of ups

Yes of course thank you for that fact and thank you for the information. Never stop learning!

 

[73's de Edd]

O.K. we saw the subtle 60 -100 or so watt incandescent lamp load, and your meters probe leads plugged into an AC outlet.
Now pull the meters probe leads and set meter ing to ~50vdc . . .UNLESS AUTO RANGING . . . . . or set the scale manually to > 25 VDC, so that no display blanking will interfere in maintaining a constant meter reading. Interested in initial DC voltage at the battery terminals and then what it drops to, to see if that is then being related to the short run time and the low AC output voltage.
In hearing the background noise . . . are you running a motor generator for AC power, or using wired local power line AC ?