EMI from forklift charger

[Bob_3]

Hello,

We have a benchtop engraving machine that was stalling and was erratic sometimes. We narrowed it down to EMI from a forklift charger on the other side of the cement block wall. This unit is supposed to run on 120V single phase, and this is a 60+ year old building that's running 123V that likely has bad/oxidized grounds throughout.

We plugged the unit into a Furman SS6B power conditioner from Amazon to isolate the line, and that helped greatly for a couple years, but now the problem is back.

Can anyone recommend a more robust line conditioner that might better suited for this application?

Thanks...

 

[IRstuff]

You could try running it from a UPS

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[3DDave]

If the wiring is that bad a fire will eventually take care of the problem. It's also possible the charger needs to be repaired.

 

[sunnysky]

Any decent line filter or a microwave oven metalized film 4 to 10 uF cap for engraving machine input. Changes are also great there are some worn-out electrolytic caps.

This will attenuate the impulse noise that is conducted. To reduce radiated noise, reduce the wire loop area of the charge cables with twists and change orientation on both sides to right angles of each other.

 

[Bob_3]

Hi All,

Thanks for the feedback, and I thought I'd give an update. First we just tried to schedule the forklift charging to off times from the engraving, but a better filter was needed too. The UPS helped a little, but but was really needed was a filter with more attenuation. The Furman unit we had only had 25dB, and we got a Schneider unit with up to 50 dB, and so far so good.

Short of the place burning down, we seem to have gotten this under control.

Thanks again...