Power distribution
- Thread starter sharan
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Need more info...!!!
First, are you really wanting to backfeed it? ...or are you just changing the supply configuration?
The first thing will be to verify 240V equipment will operate on 208V as currently implemented. This will also include verifying properly sized OCPD and conductors, as the current levels will be different.
The 120V equipment should not present any problem, but you will have to verify there are no reduced-in-size neutral conductors for any L-N-L loads.
If changeover presents a fair amount of problems, you may want to consider using a transformer.
First, are you really wanting to backfeed it? ...or are you just changing the supply configuration?
The first thing will be to verify 240V equipment will operate on 208V as currently implemented. This will also include verifying properly sized OCPD and conductors, as the current levels will be different.
The 120V equipment should not present any problem, but you will have to verify there are no reduced-in-size neutral conductors for any L-N-L loads.
If changeover presents a fair amount of problems, you may want to consider using a transformer.
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Okay. To me that's not backfeeding it, but rather resupplying it as a subpanel (or separately derived system if using a transformer).
Optimally, use a 208V delta to 240/120 delta transformer... but it may not be a commonly stocked item. Minimum rating will depend on calculated load and connected equipment. For full 400A rating your looking at 167kVA minimum.
NOTE: Resupplied as a subpanel, you will have to isolate equipment ground, grounded neutral conductor, and GES. Resupplied as a separately derived system, isolation of the preceding will not be necessary.
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When you say separately derived system, you mean feeding it thru the transformer?
Okay. To me that's not backfeeding it, but rather resupplying it as a subpanel (or separately derived system if using a transformer).
Optimally, use a 208V delta to 240/120 delta transformer... but it may not be a commonly stocked item. Minimum rating will depend on calculated load and connected equipment. For full 400A rating your looking at 167kVA minimum.
NOTE: Resupplied as a subpanel, you will have to isolate equipment ground, grounded neutral conductor, and GES. Resupplied as a separately derived system, isolation of the preceding will not be necessary.[/QUOTE]
Okay. To me that's not backfeeding it, but rather resupplying it as a subpanel (or separately derived system if using a transformer).
Optimally, use a 208V delta to 240/120 delta transformer... but it may not be a commonly stocked item. Minimum rating will depend on calculated load and connected equipment. For full 400A rating your looking at 167kVA minimum.
NOTE: Resupplied as a subpanel, you will have to isolate equipment ground, grounded neutral conductor, and GES. Resupplied as a separately derived system, isolation of the preceding will not be necessary.[/QUOTE]
Yes.
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