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industrial power conditioning 3 phase 480V

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iceworm

Electrical
Jun 19, 2009
215
I have a customer that is getting beatup (power electronics) with what I think are switching transients from Back-to-Back capacitor switching. This is off-grid self generation. The transients are their own making.

The customer is interested in powerline conditioners. Nominal spec:
480V
impedance grounded Y
3 phase
25kva output

The question:
Does anyone have recomendations for known high reliability brands?

ice
 
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for surge protection. AusLee's suggestion is a good one too. If your transients are very high-energy, consider downstream protection as close as possible to the equipment you're protecting as well.

Also, if you want to really go overboard cleaning it up, a sine wave filter downstream of the surge protection would do the trick. ABB, Danfoss, and a bunch of others make them in a wide range of sizes. 25 kVA is no problem.

Best to you,

Goober Dave

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Another alternative that would probably be more expensive but would likely solve all your power issues is to invest in a UPS (uninterruptible power supply). Many manufacturer's offer solutions in the 30 to 50 kVA range. I would install a surge arrestor on the input to the UPS. I have used the Emerson/Liebert products such as the ACV series see web site The key to good surge suppression is to have the lead lengh as short as possible between the surge arrestor and where it is connected to the circuit. For example if you were to place a disconnect on the line side of the UPS you would want to mount the surge arresor right on the disconnect with as short as possible wire leads into the disconnect connectiong to the lugs. Most of these surge arrestors are installed in parallel with your circuit and the MOVs clamp the surge voltage to a minimal value. As for the UPS make sure you get a true double conversion UPS. You probably don't want much battery as this adds expense every three years when the batteries should be replaced. I have had good success with he Mitsubishi UPS and the Liebert/Emerson UPS lines.

Hope this helps.
 
Thanks. I appreciate the responses. They will narrow down the research.

ice
 
They might also consider putting reactors ahead of those capacitors. Slows down the rise time of the transients.

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