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I was wondering if a battery charger rated at 240V 60 Hz 3 phase input can be somehow made to work properly if I only have 240V 60 Hz single phase available. I know there are expensive phase converters available on the market but I want to try to avoid those because of cost reasons. So would 240V single phase possibly damage a device designed for 3 phase input?

The requirement on the input side is up to 11A at 240V (3 phase) but the charger is also rated at up to 13A at 208V. I might be able to get a 3 phase feed from my local power company but as of right now, I only have split phase 120V which means I can easily get 240V.

The purpose of this very high output charger is for just that, rapidly charging a large battery bank that can handle it. My existing other chargers are quite slow so I wanted to possibly use this one instead.

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    \$\begingroup\$ Is this charger using a linear or a switching topology? 33A@240V is manageable in the North American split phase system...also, is this charger designed exclusively for a delta or a wye topology, or can it be field wired for either? \$\endgroup\$ – ThreePhaseEel Oct 4 '16 at 1:17
  • \$\begingroup\$ @ThreePhaseEel - I will inquire about this but another option I may have is to request a 3 phase feed to my house from the local utility company. If the cost is reasonable I can get it, otherwise I won't do it. \$\endgroup\$ – David Oct 4 '16 at 10:38
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    \$\begingroup\$ The local utility will probably not even talk to you about getting a 3-phase service for a single-family residence or even a small multi-family residence or commercial building. If they are willing to provide the service, it is highly unlikely that the cost will be less than the cost of buying a charger for the existing service. I think @dave_tweed has provided exactly the answer you need for the existing charger and service. \$\endgroup\$ – Charles Cowie Oct 4 '16 at 16:33
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A simple (e.g., no power factor correction) 3-phase charger or power supply generally has a 6-diode bridge as the first item (perhaps after some filtering components) on the input side to create an internal DC bus. You'll want to verify this before proceeding.

If you connect a single-phase source (of the appropriate phase-to-phase voltage) to two of the input terminals, you will be using just 4 of the diodes. This should work just fine, as long as you keep the load to 2/3 of the 3-phase rating, so as not to exceed the capabilities of the diodes.

If the charger is a modern one with power factor correction, the input circuit will have 6 MOSFETs (or maybe IGBTs) instead of the diodes. In this case, you'll have to ask the manufacturer about single-phase operation. Depending on how they sense the currents and voltages for the PFC function, it may or may not be possible.

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It is extraordinarily unlikely that you could get enough CURRENT (Amps) out of a single phase to properly supply a circuit that was designed for 3-phase input. You did not mention any current specifications, either for the mains supply, or for the rated output of the charger, or for what you need for your proposed use.

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    \$\begingroup\$ Thanks for pointing that out. I have updated my question with the additional info. \$\endgroup\$ – David Oct 4 '16 at 0:45
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    \$\begingroup\$ It is remotely possible that you could get away with feeding it only two phases (two 120V phases = 240V total). But you would have to significantly de-rate the charger to perhaps only half (or less) the otuput that it was designed to provide. But I wouldn't bet on it. \$\endgroup\$ – Richard Crowley Oct 4 '16 at 0:49
  • \$\begingroup\$ That would actually be fine because the maximum output of the charger is more than I really need so would a 120 + 120V split phase setup be considered 1 phase or 2 phase? To me it seems it would still be 1 phase since the pair of 120V mains are phase locked 180 degrees out of phase with each other. \$\endgroup\$ – David Oct 4 '16 at 0:52
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    \$\begingroup\$ You really need to examine the schematic diagram of the charger to determine if it was even feasible. Absent proper information I would bet that this was NOT possible, practical, or even safe. It would be a dangerous kludge at best. \$\endgroup\$ – Richard Crowley Oct 4 '16 at 0:54

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