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  1. dtlxii

    120VAC for two panels with one transformer

    Thanks guys. Maybe I'm looking at this wrong. Neutral should be 0 volts because it's bonded to ground at the transformer, so there should not be an issue then. I got confused because I read somewhere that if you share a neutral, and you switch off one of the circuits, all circuits using that...
  2. dtlxii

    120VAC for two panels with one transformer

    If I use a 4-pole contactor instead of the 3-pole shown in the drawing so I can switch the neutral as well as the hot legs, would that work? Would it violate any NEC codes? Thanks for your help.
  3. dtlxii

    120VAC for two panels with one transformer

    My bad!! I apologize for the confusion and insulting everybody's intelligence. By trying to make a simpler version of the circuit in MSPaint I got things confused. Please see the new drawing. So, here is how it works: Panel 1 would be on all the time. It contains a 3-phase, 480 to 208 VAC, 30KVA...
  4. dtlxii

    120VAC for two panels with one transformer

    Panel 1 provides 480 VAC to Panels 2 and 3, but these two panels don't do anything until their own switch is turned on. If you look at the drawing, when panel 2 (in the next compartment) is turned on, it feeds a small 480/24 VAC control transformer in that panel. It is this 24VAC that then...
  5. dtlxii

    120VAC for two panels with one transformer

    I want to use a control panel enclosure with three compartments to house the main power in one, and two independent panels that get their power from the main compartment but have their own disconnect switch. They will power VFDs but also provide 120 VAC for other controls along the machines.The...
  6. dtlxii

    Equipment nameplate

    The motor is indeed inverter supplied from 208 VAC from a control panel. Everything else is 110 VAC. The DC supplies are for FETs driving 24VDC solenoids and some seven-segmnent displays. I'm confused as to what would be the AMPS and the FULL-LOAD AMPS. I'll try to get a clamp to measure but I...
  7. dtlxii

    Equipment nameplate

    Hello. I need to come up with a nameplate for equipment we built and it has to state amps and full-load amps. It's a 3-phase, 208 VAC machine that has a 1/2 hp motor (1.8 Amps as per motor nameplate) and a few DC power supplies. How do I go about calculating these values? Do I add the 1.8 amps...
  8. dtlxii

    Step down transformer for Asia

    Thank you. Yes, I think that would work too. Just one more question. This transformer has a Delta input and Y output. Does it matter if the customer has a Delta or Y? I would think that it doesn't matter as they would not connect the neutral to the transformer if it was a Y, but I'm not sure...
  9. dtlxii

    Step down transformer for Asia

    Waross is right, but I think if I buy a 3-phase, 480/240, 15 KVA, 50 Hz transformer, I can use it in Singapore to hookup 415 VAC and get around 208 VAC, 50 Hz. Is this correct? My equipment (208 VAC, 30 A) has components rated at 50/60 Hz so frequency is no a problem, but I was a bit confused...
  10. dtlxii

    Step down transformer for Asia

    Ok. What about using a 480/240 transformer, 50 Hz.? Would a 415 VAC input produce a 208 VAC output with no problems? Thanks for your help.
  11. dtlxii

    Step down transformer for Asia

    Thank you. I know. Our machine can handle the 50 Hz. But I can't find anything for 415 VAC input. We need 208, Y-connection. I don't know if the customer has Delta o Y.
  12. dtlxii

    Step down transformer for Asia

    I need a transformer for a machine being sent to Singapore. The machine uses 3-phase, 208 VAC, 30 Amps, 60 Hz. The plant supplies 3-phase, 415 VAC, 50 Hz. I know it should be around 15KVA rating but I'm not sure what transformer to get. Any help/suggestion is greatly appreciated.

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