DC Battery Bank charger outputting too much AC

[LHammermeister]

Hello all, I have a NIFE Powertronic DC Battery bank charger that my company uses as a DC source for the commissioning of Load centers/ a DC source to cheat in power. It was recently tagged out saying that there was to much of an AC component on the output and it may lead to damaging energized equipment. Initially all a plugged the device in and measured the DC which was around 137 VDC then the AC which was 104 VAC!!! Right away i thought that this was the result of a faulty SCR. In our shop we have a second charger of a different model and I measured 2 VAC on the output further leading me to believe that the SCR was the issue. After changing the SCR the output still contains the 104 VAC component and I was wondering if anyone could give me any ideas on what may be causing this. I have attached pictures of the charger, nameplate, SCR we replaced and a rough sketch of what the wave looks like can be seen drawn on a piece of paper on the front of the device.

Any information would be AWESOME!
Thank you for your time.

[SecondGen]

First thing that comes to mind is bad rectifiers. You seem to be on the right track. If you had a schematic I might be able to narrow it down to a few components.

[LHammermeister]

First thing that comes to mind is bad rectifiers. You seem to be on the right track. If you had a schematic I might be able to narrow it down to a few components.

It sure makes it tough when the company the origianlly manufactured the device has been purchased and sold a couple of times, I haven't been able to find anything online. It still puzzles me why after changing the SCR out it didn't have any effect on the waveform output. Now looking for new ideas, would the voltage at the gate or lack there of cause an issue like this? Any thoughts would be greatly appreciated!

Thanks!

[Ore905]

It sure makes it tough when the company the origianlly manufactured the device has been purchased and sold a couple of times, I haven't been able to find anything online. It still puzzles me why after changing the SCR out it didn't have any effect on the waveform output. Now looking for new ideas, would the voltage at the gate or lack there of cause an issue like this? Any thoughts would be greatly appreciated!

Thanks!

Hi first post here. You should look into your filtering capacitors and be careful with the loads connected to the charger/rectifier. Electronic protections with electronic power supplies will cause ac ripple in an older charger without it's batteries connected. Our vendor installed filtering capacitors for this scenario.