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I want to use a use a rectifier (Eltek Aeon SMPS 4000 Rectifier, used in telecom) as a stand alone DC power supply (puts out 24v/125a). The unit was designed for 3 phase 220v AC input. I have only single phase. Is the unit likely to function on single phase? If so, would there be any performance loss on single phase vs 3 phase input?

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The answer is.... Maybe.

It depends on the input topology of the power supply.

Their calling it a "Rectifier" is very confusing. What you have is really just a big DC power supply.

Generally, (ignoring the power-factor-correction electronics), the input of a switch-mode power supply is simply rectified to high-voltage DC, which is then converted to the desired output voltage using a DC-DC switching converter (hence the "switch mode" in the description).

If you're lucky, the power-factor correction electronics won't cause an issue with only a single phase, and you simply need to de-rate to 66%, as Spoon said.

You have to derate as you're only using part of the input rectification. Normally there are six input diodes forming a three-phase bridge rectifier. Since you would be only using two of the three power connections, you would only use four of the six diodes, hence the derating.


Really, the only way we can say anything definite about how the power supply will work would be to get a copy of the schematic, or trace out the PCB.

It will probably work, but there can be non-obvious side-issues, like reduced lifetime, etc... If this is just for your own experimentation, you're probably OK.

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If I'm reading this correctly each "rectifier" is a single phase unit; 3 phase installations use banks of six of them, possibly 2 on each phase for failover. See waveform on slide 6, functional diagram on slide 10.

In which case it would work fine. It comes from a country where 230V AC single phase is the normal domestic supply.

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  • \$\begingroup\$ Link is broken - can you copy & paste the relevant content? \$\endgroup\$
    – John U
    Jul 22, 2013 at 12:33
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Short answer is No, unless you know something specific about your power supply. Even if it does work, you have to derate to 1/3 the normal output at the very least as others have said.

There are two likely AC input topologies: brute force rectification and individual rectification with PFC (Power Factor Correction).

Brute force rectification means that the rectifiers are arranged to take the max of the abs of the three power signals. This effectively switches between the phases to pick off only the peaks. One important feature of this is that the result is always actively driven to some minimum voltage. The circuitry making use of that voltage may very well rely on that. With a single phase you are not only supplying 1/3 of the possible input power, but the DC voltage after rectification goes to zero twice per line cycle. This can cause more problems than just not having as much power available. The supply may be unable to hold up the DC output during parts of the AC line cycle, whether you derate according to the lower input power or not.

The best scenario is you have separate PFC front ends on each phase without special circuitry that checks for a phase dropout. The supply then draws current from each phase separately as a function of its voltage. This will allow making use of a single phase, but again keep in mind that the input power goes to 0 twice per line cycle, which never happens when all three phases are available. The available output power may be considerably less than 1/3 of the 3 phase case.

You are basically asking if you can use a carefully designed piece of equipment out of spec. The answer is always "no", unless you know something more than just the specs. You can't count on how exactly the designers made use of the promise that all three phases would always be present. It might work, but you should not assume so, and you can't complain when it doesn't.

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Short answer is Yes.

However you have to de-rate the rectifier to 67% of its current rating.... that's from memory.

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  • \$\begingroup\$ Your answer reads as if you didn't actually look a the component the OP asked about. Note that while it's called a "rectifier", it is far more than a simple diode bridge. \$\endgroup\$
    – HikeOnPast
    Feb 18, 2013 at 20:00
  • \$\begingroup\$ I haven't had a chance to dig out a Drive manual but they let you do it... a Drive is a rectifier input stage and an inverter output stage. However there are good answers already so I'll leave it to them.... \$\endgroup\$
    – Spoon
    Feb 18, 2013 at 20:22
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Of course it it possible. I work with these equipments and i have no doubt about that.

Regardless the AC Fase R S ou T. the output é DC (continuous current) So the potencial ate the exit of each rectifier module is the same.

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    \$\begingroup\$ I don't see how this answer contributes to the other answers. Also it has been stated it it not really "of course possible" but may depend on several factors. \$\endgroup\$
    – Rev
    Jul 22, 2013 at 11:44

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