Generator input xw6048

adam1984 · May 2011

So i have a Honda EU3000i, and the XW6048. I would like to use the EU as the Gen. Input, however the output is 120 and the XW's only accept 240V. It seems a simple step up transformer would work, but is there any other solution? Also, should it be a 3kVA Transformer or oversized, such as 4kVA? I made a mistake and thought the EU's had 240 out. Any sources for good transformers?
Thanks,
Adam

BB. · May 2011

Re: Generator input xw6048

An Autowound type transformer may work OK... But there is no isolation so you will have to watch the neutral and earth grounding.

Another option--You can reconfigure new (all?) XW hybrid inverters to pure 120 VAC operation--Basically rewire the internal 120/240 VAC split phase pair of outputs into a pair of parallel connected 120 VAC transformers for full rated power at 120 VAC only. (I believe you need to install new firmware too).

Yea--that 240 VAC generator input catches a few people. It would have been nice if they accepted (at limited rating) 120 VAC too without rewiring the XW.

Actually-there is one more option--and unless you plan on running the eu3000i genset a lot (i.e., you do not have solar panels, or not very many of them)--I would instead look at getting a simple AC battery charger to connect the 120 VAC generator directly to the battery bank through the AC battery charger.

It is not as efficient--but if you don't use the generator that much--it will still nicely meet your needs. I am a big believer in "smallish" and fuel efficient gensets running at 50%+ load rather than larger 7.5-10kW gensets running 1-2kW of battery charging.

-Bill

RCinFLA · May 2011

Re: Generator input xw6048

I have a Yamaha EF3000sei, close equivalent to the Honda EU3000.

I use step up isolation transformer to feed 240 vac to inverter.

You can use a 2kVA transformer wired as autotransformer to give 4kVA capability. I used two 2kVA transformers with 120/240v primary and 120v/240v secondary winding which gives many connection options for step up/step down/isolation, or can be wired as autotransformer.

The less then 3kVA inverter/generators really should not have their neutral grounded so I used two transformers wired in total isolation configuration.

The transformers are 53 lbs each. When I bought them eight years ago they were $160 each. Now I think they are up to about $260 each.

Make sure you set the max AC2in amps (via "breaker size") on inverter to about 10 to 11 amps to avoid overloading generator.

mike95490 · May 2011

Re: Generator input xw6048

RCinFLA wrote: »

....sformers wired in total isolation configuration.

The transformers are 53 lbs each. When I bought them eight years ago they were $160 each. Now I think they are up to about $260 each.......

Do you have a Mfg/part # for them ?

RCinFLA · May 2011

Re: Generator input xw6048

Ouch!

Just looked them up. Now $650 each! Maybe I paid about $260 each eight years ago.

Thordarson 23V608

http://www.alliedelec.com/search/productdetail.aspx?SKU=7040057

niel · May 2011

Re: Generator input xw6048

RCinFLA wrote: »

Ouch!

Just looked them up. Now $650 each! Maybe I paid about $260 each eight years ago.

Thordarson 23V608

http://www.alliedelec.com/search/productdetail.aspx?SKU=7040057

unfortunately we get just as much of a shock from the price of the copper as we do from the power flowing through it.:grr

mike95490 · May 2011

Re: Generator input xw6048

well, I've found some 5 KVA transformers on flea bay, and want to use them as load balancing for my xw6048 inverter. Maybe it's a bit of overkill, but if something needs a surge, I don't want to saturate the transformer, and have it drop off. Currently, I wonder what happens when my 240V well pump is running, (several hours a day) and a large un balanced load pops up, will the pump windings try to "balance" the load ? Anyone have ideas what happens if I use a small 240 - 120V transformer at the end of a 900' run, (it powers the ozone generator for my water tank) will it try to "balance" loads, and burn up ?

BB. · May 2011

Re: Generator input xw6048

Don't connect the inverter neutral to the transformer, and it should not balance the loads on the inverter.

Check the standby loses on the transformers, they may burn 5% of their rated power (swag).

If they only run part time, you may want to put an ac disconnect before the transformer inputs.

-Bill

Solar Guppy · May 2011

Re: Generator input xw6048

Mike, Don't worry about it

The XW tranformer won't saturate with an imbalanced load, the derating is due to the IR losses, nothing more. For power on surges your concerned about it won't do squat to the transformer.

The XW is rated 1 minute at 2X its rated load, transformer saturation is impossible as the DSP will current limit as needed

Dave Angelini · May 2011

Re: Generator input xw6048

The XW will also load support and draw current from the battery if the unbalance is not too great. The manual lists the amount of in the specs but you really have to test it with your set-up and 120VAC generator.

If you win the lottery there is not really a better match for the XW than a 6500i from Honda.

mike95490 · May 2011

Re: Generator input xw6048

Saturating the core of my .1VA transfromer is what I worry about, not the XW.

It's the imbalance in my loads, shutting down the XW, if I pull too much from 1 leg. And yes, the standby losses on a transformer are much worse than I imagined, 5-8% of rated load, not actual load.

I don't know what happens to the XW if I get too imbalanced, does it just limit, shut off and reset, or does it need manual restart ?

mike95490 · May 2011

Re: Generator input xw6048

BB. wrote: »

Don't connect the inverter neutral to the transformer, and it should not balance the loads on the inverter.

Is there a typo in there ??

Good idea about being able to switch off the transformer.

BB. · May 2011

Re: Generator input xw6048

I don't think so--but my English is a bit condensed (short post from me? Never :roll:).

Basically just connect the Line A / Line B from the Inverter to the input of the 240:240 VAC transformer. Do not connect the neutral lead of the transformer intput (if any) to the inverter.

-Bill

Solar Guppy · May 2011

Re: Generator input xw6048

Mike, the voltage is fixed by the XW transformer, your inventing a problem that doesn't exist.

mike95490 · May 2011

Re: Generator input xw6048

Solar Guppy wrote: »

Mike, the voltage is fixed by the XW transformer, your inventing a problem that doesn't exist.

Voltage is not my concern, it's un-balanced loads between the inverter Phase 1 & Phase 2 leads. In the manual, it states there can only be a 75% difference between them, or the inverter will fault. (doesn't say if it's an auto reset fault, or a manual reset)
Anything in the system that can act like a transformer, (240V motor or small wall wart 240V transformer) will try to perform the balance on it's own, which may not be healthy for any devices. Anyway, I scored a 3KVA transformer off ebay, [MARCUS RES3B2], been looking for a couple weeks, and I'll have it on hand, just in case...

So, if I want to pull 3000W from one circuit, the other leg needs to have close to 900W load also. I don't know how often I could find myself in that condition, but I'm sure my wife will manage it. I'm trying to not have to install 2 inverters, I think our lives can deal with the 6KW limit of a single one.

( and BB - that's the ticket, leaving the center tap float )

So I think I set it up like the Trace T240 manual figure 13

Solar Guppy · May 2011

Re: Generator input xw6048

Mike,

I still don't see the issue. The imbalance is purely and IR thing. The XW is a huge doughnut core that has the winding overlapping the entire core many times, the 75% rule gets into the issue that if your loading only half the winding, you will get into a voltage imbalance in respect to a neutral to hot measurement and the DSP had no means to compensate.

A load will never "balance" anything and your not pulling excess current thru a load transformer in the method your concerned about, if for no other reason that your little load transformer are very high resistance compared to the XW's core

Again, your inventing/over thinking this, or that's my perception in reading your concerns. Have you even see an issue?

mike95490 · May 2011

Re: Generator input xw6048

Nope, have never seen an issue, but I do know in 6 months, when I move in, I'll be loading the system pretty heavily, and maybe asymmetrically.

So, I suppose I'll leave the transformer on standby, and not hook it up yet.

RCinFLA · May 2011

Re: Generator input xw6048

The transformer core has the limit and can supply 6000 VA (with 12000 VA surge). Beyond that the MOSFET/control of the XW will limit the drive to primary side.

As to the secondaries, they are two independent winding. Pulling 6 kVA from a single 120 v winding would only impart excessive wire resistance drop from that winding, not saturate the core. This IR drop is the reason the single sided 120vac load is limited to 41 amps (4.9 kVA).

As to a combination of 240vac and 120 vac loads, it all applies to the max kVA sum and the max current from each of the secondary windings. No more then 6kVA (12kVA surge) total load or limit continuous load of 41 amps through one of the two secondary winding legs.

As to the external transformer to take 120v gen to 240vac, you need to set max ACin2 current level. As I recall, the mutated software on XW calls it input breaker size. The AC current input is limited to 80% of breaker size setting. So if you want to limit 240vac input to 10 amps you have to set breaker size setting to 12 amps. Also have load shaving enabled to allow the inverter to make up any larger load on ACout.

Question to BB on your comment on not connecting neutral.

Does the XW gen input allow just 240 vac applied (just L1,L2 connections) without a generator neutral connection? I can see it qualifying as long as there is not a qualifying check on 120vac between neutral and AC2in L1,L2 before relay closure. I don't think it is a good idea especially if generator has neutral connected to generator housing. There could be a slight voltage potential between ground and generator case due to ACout neutral-ground connection.

I assume there is not a separate neutral relay connection to ACin's neutral so there will be a path on AC1in through neutral-ground point in master breaker box from ACout neutral connecton to a aux box neutral return to master breaker box so it would not be a good idea not connecting neutral for AC1in grid input.

I always wondered about grid tie with XW having a 240vac common transformer with neutral connection. Any grid imbalance will try to be corrected by XW transformer, potentially overloading it. If your neighbor, on the the same pole transformer, ties a 2 HP pump wired for 120 vac that causes IR drop on that leg, the XW transformer will try to balance it back to grid to prop up the sagging L-N leg.

I have two series stacked SW4048's and I can see the DC current push from one unit to the other when L1-N-L2 is slightly imbalanced due to 120vac loads.The two independent units (and transformers) do track the L-N variation on their side but there is some time delay.

mike95490 · December 2012

Re: Generator input xw6048

RCinFLA wrote: »

......Make sure you set the max AC2in amps (via "breaker size") on inverter to about 10 to 11 amps to avoid overloading generator.

So, what are all the settings needed to charge batteries from an off grid genset (AC2) while inverting :
(loads to have priority, charging with surplus power)

ENABLE GENERATOR SUPPORT ?

AC2 BREAKER max amps (11 amps for a 3,000w generator, 2640w cont) ?

Max Charge Rate ( 2640W @ 55V = 48A ) ?

I expect to usually have < 1.5Kw of actual loads (if I'm running my pump) so most of the power will be for bulk recharge while I'm awaiting sunshine.
[ to view advanced settings press ENTER & UP & DOWN at same time ]

Thanks,
Mike (in rain & snow flurries)

Generator input xw6048

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