Is there such thing as 4kW, 115VAC , single phase equipment?

[treezleef]

Hi,
We are being asked to make a power supply for a Bass amplifier......its 4kW, from 100-265VAC.
Does that sound right?
Woudlnt 4kW from 115VAC always be done with three phase?
(this kit is for mulitple different countries)

 

[pc1966]

If you want something to be easy to use in most place is will be single phase. It is uncommon outside of industrial units to have a 3-phase socket, having said that, it is also uncommon to see sockets above 32A as well.

4kW at 100V is at least 40A (assuming PF=1) so it is hardly a trivial load, and you also have to consider switch-on surge and as probably an electronic load, correction to ensure the current drawn is nearly sinusoidal. Look for an off the shelf PSU unit that meets most of the requirements and then consider anything else.

This is probably one for @Lucien Nunes

 

[Lucien Nunes]

In 120V territories e.g. USA there is often 240V split-phase available, with the two 120V hots either side of neutral. Loads of 4kW would normally be run at 240V, e.g in a domestic setting the tumble dryer would usually be 240V. There are 30A and 50A outlets but they will often be 240V too e,g. NEMA 14-30 and 14-50 and legacy 10-30 and 10-50 without neutral. There are 120V outlets, 5-30 and 5-50, but I think you're more likely to find 6-20 i.e. 20A 240V. Three-phase can be either 240V line-line (edge-grounded delta from 120-0-120) or 208V (from 120 star) on the NEMA 15- and 18- series receptacles.

Interested to know the nature of the project - is this a design for a product or a one-off? Is it really 4kW as in a really real 4kW? Even in the realm of high power PA amplifiers, that is a big amplifier. What is the PSU - twin rail, multirail, switching only, tracking post-reg or what? Just curious.

E2A Japan is 100V nominal and can be as low as 90 at peak load. 3-phase is 200V edge-grounded delta with 100-0-100 derived as per USA.

 

[treezleef]

Yes its really 4kW of real power. PSU is a 4 stage interleaved Boost PFC into two 2kW LLC converters. It is a design for a product.
Since Music is naturally pulsating, i am thinking that 4kW is either the peak load or average load...i am not sure which.......we were just asked to come up with a 4kW PSU, that could do 4kW constantly, from 100VAC to 265VAC.

 

[pc1966]

It might be your best option to discuss with the final client, as from Lucian's feedback it would seem that USA/Japan could have a 200-240V split supply that would result in more sane operating current levels.

If you have a current-limited arrangement then if it is below ~180V input you might have to look at winding back the output power to around the 2kW sort of region. That might be a tolerable compromise for occasions when a suitable socket is simply unavailable.

Having said all of the above, if this is likely to be used only at big events where total power is in the 100kVA or more region then having 230/400V or 120/208V three-phase sockets might well be the norm.

 

[DPG]

Yes its really 4kW of real power. PSU is a 4 stage interleaved Boost PFC into two 2kW LLC converters. It is a design for a product.
Since Music is naturally pulsating, i am thinking that 4kW is either the peak load or average load...i am not sure which.......we were just asked to come up with a 4kW PSU, that could do 4kW constantly, from 100VAC to 265VAC.

You definitely need to get a better spec from the requester. You can't really design and cost for such a big power supply without knowing what the exact requirements are. Guessing if they need 4kW peak or RMS could lead to a costly mistake or a disappointed customer.

As Lucien says, 4kW is a very hefty amount of power.

 

[DPG]

Does your company have an official procedure for agreeing specs, delivering prototypes, etc?