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satnat.2008
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Join Date: Oct 2011
Posts: 34

230V AC Supply Has Got Mixed With 220V DC Supply

05/15/2012 2:47 AM

in one of my power plant project . we have a battery charger with inbuilt DCDB. the rating of battery is 400Ah .

After commissioning the battery charger we found that 220V DC supply output found good and the system is running fine.

Suddenly one day we found that 230VAC supply is getting mixed up with DC output bus . after checking we found that AC supply is back feeded from a panel due to wrong wiring .

now my douts are as follows :

1) can AC supply mix up with DC Supply ?

2) whether it will affect my DC equipments like relay , solenoid coil , trip coil etc ,.?

3) one of my solenoid coil has got De-energised and now my client is saying that this has happened due to this the AC supply mix up with DC Supply . Is it due to that ?
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PWSlack
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#1

Re: 230V AC Supply has got mixed with 220V DC SUPPLY

05/15/2012 3:22 AM

Why did the overcurrent protection device not operate?

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PWSlack
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#2

Re: 230V AC Supply has got mixed with 220V DC SUPPLY

05/15/2012 3:41 AM

A1) yes.

A2) yes.

A3) yes.

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Andy Germany
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#9
In reply to #2

Re: 230V AC Supply has got mixed with 220V DC SUPPLY

05/16/2012 8:04 AM

GA. Short and accurate!!

LOL !!!

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kvsubramanyam
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#3

Re: 230V AC Supply Has Got Mixed With 220V DC Supply

05/15/2012 8:32 AM

very confusing. how can dc mix up with ac? ac and dc (currents) can flow in same conductor. if you pass dc through ac solenoid it will burn. if pass ac through dc solenoid it will not burn.

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jack of all trades
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#4

Re: 230V AC Supply Has Got Mixed With 220V DC Supply

05/15/2012 3:17 PM

Are you sure there is a physical circuit wiring problem and not just an AC signal being inductively coupled onto the DC bus?

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leveles
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#5

Re: 230V AC Supply Has Got Mixed With 220V DC Supply

05/15/2012 11:29 PM

Are you sure, that one of the rectifier / regulator is not internally defective? A shorted rectifier or DC regulator component can put AC hum onto its DC output. If in doubt, simply measure the current components.
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pnaban
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#6

Re: 230V AC Supply Has Got Mixed With 220V DC Supply

05/16/2012 12:59 AM

In the wire where both ac & dc got mixed connect a data logger/power analyser and record the waveform.

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Haajee
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#7

Re: 230V AC Supply Has Got Mixed With 220V DC Supply

05/16/2012 7:49 AM

Regards.

Please have a 2nd look into your system and clarify what the DC power is doing here?

Are you using the UPS or Inverter for your system?

Or .... ?
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corbinstein
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#8

Re: 230V AC Supply Has Got Mixed With 220V DC Supply

05/16/2012 8:01 AM

If no changes were made to the system to cause this, I'd seriously suspect a rectifier...
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Users who posted comments:

Andy Germany (1); corbinstein (1); Haajee (1); jack of all trades (1); kvsubramanyam (1); leveles (1); pnaban (1); PWSlack (2)

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