Dual XW6048

MichaelB · May 2010

Im checking if anyone here is running or works on a Dual XW6048 system with regards to AC1.

I currently have a 6Kw 30 panel system connected to 2 Xantrex charge controllers and a single XW6048 Battery backed grid tied inverter.

AC1 normally is used to feed the Inverter and sells back 100% to my main panel all the time feeding anything the home requires. What my home does not need flows back to the grid. I am not using a Inverter sub panel for dedicated circuits.

System works great as is.

My issue is that my home runs on Geothermal A/C and when the compressor kicks in along with the well pump to supply ground water my Xantrex trips the breakers when Im running on solar/battery power and no grid support.

Im considering adding a second XW6048 and connecting with the XBus network so they run parallel and thus cover my surge loads. I will share the same battery bank between XW units. I will share the 2 existing solar feeds from unit 1 and I will most likely program both XW units to share load at 50%.

Im not expecting any issues but just wondered if anyone has or if they suggest something different.

mike95490 · May 2010

Re: Dual XW6048

What breakers trip ? AC DC ? How big are these 2 systems, and what are their loads ? heat pump has at least 2 big fans, and a compressor motor, and what size is the well pump? Can any motors be converted to 230V, it's easy to get unbalanced 120V loads.

MichaelB · May 2010

Re: Dual XW6048

mike90045 wrote: »

What breakers trip ? AC DC ? How big are these 2 systems, and what are their loads ? heat pump has at least 2 big fans, and a compressor motor, and what size is the well pump? Can any motors be converted to 230V, it's easy to get unbalanced 120V loads.

Actually I should have said my xantrex shuts down the heavy load exceeds 6Kw.

My Well pump uses 14amp and the geo unit eats another 40 with the fan & compressor. The breakers never trip..just shutdown..once the load is removed
the xantrex auto powers back up.

If I use 2 xantrex shared then I should have upto 12Kw of available power.

Solar Guppy · May 2010

Re: Dual XW6048

Sounds like a power quality issue as you said the XW has nothing on the load side, it can't be overloaded on the AC1 side as it only sells to that if the UL1741 conditions are valid ( line voltage and frequency ) and only to its progammed maximum which can't overload the unit

So what exactly do you mean by shutdown?

RCinFLA · May 2010

Re: Dual XW6048

The XW can take a surge startup of about 53 amps for 240vac.

When you say 40 amps for your A/C I assume you mean start up surge. 40 amps at 240vac run would be a very massive unit ( about 8-9 ton, 100Kbtu's).

16 amps for a water pump is very large for a run level.

If you are starting both at the same time it would be advisable to delay the pump start by 10-30 seconds.

Is your geo-thermal A/C require the pumped water for condenser cooling? If only for residential water then a priority switch could prevent concurrent operation.

You need to know the start and run currents.

I have a Lennox 3 1/2 ton that compressor take 120 amps @ 240v for 400 msec on startup. Run current is 14 amps @ 240v. I have two series connected SW5048 plus inverter just to start the compressor.

Solar Guppy · May 2010

Re: Dual XW6048

MichaelB wrote: »

AC1 normally is used to feed the Inverter and sells back 100% to my main panel all the time feeding anything the home requires. What my home does not need flows back to the grid. I am not using a Inverter sub panel for dedicated circuits.

RCFLA , From the original post, no loads on the XW-6048

RCinFLA · May 2010

Re: Dual XW6048

Are you running your whole house through the XW or just using XW connected to main grid for solar grid-tie with no battery backup to your house loads?

RCinFLA · May 2010

Re: Dual XW6048

Solar Guppy wrote: »

RCFLA , From the original post, no loads on the XW-6048

Ah, okay ???

Even if done this way with grid feeding loads, XW should regulate its sell capability on its own.

A sudden dip in grid voltage due to startup surges may cause XW to disconnect. This would be an AC1 failure, not an overload failure.

MichaelB · May 2010

Re: Dual XW6048

This should actually be a conf call..lol

Lets see here.

Im cutting OFF the grid service with a 400amp knife switch so Im solo..aka grid down.

Sun is shining so Im getting about 5.5KW solar and 625amps of battery are available.

XW is feeding 100% of its generation available back into 2-60amp breakers on the Main Panel. This allows me to turn on anything in the home I wish as long as I dont overload the XW unit with max draw...6K

Home draws 500watts according to my XW LCD..This is phantom loads..clocks..bs

Geo unit ( waterfurnace 5 Ton ) gets a cooling need so the fan spins up.. XW now shows 800watts draw so my Fan is using about 3amps.

Geo unit after about 30sec cracks open the water loop valve which triggers the well pump to spin up ( 220V 14amp deep well ) XW now shows 2300watts load.

Geo unit 4 seconds after opening water valve spins up compressor.. XW goes to 6100 load for about 1 second then shuts down...

Geo unit has no power now and dies...XW after about 10sec now goes back online with only phantom loads..

I know the Geo Unit and well if timed correctly..fingers crosses and a wave of the magic wand with nothing else in the home running will run on the XW but its at 5500watts load on the display...

So Im guessing the surge of the compressor is just over the XW limit..

I do not have a way to add more dwell time between pump and compressor.

I have a 6000SqFt home so its hard to cut off all phantom power.

Im thinking that by adding a second XW in parallel and connect AC1 back to the main panel on its own set of 60amp breakers then I have plenty of power avail to run pretty much everything within reason.

RCinFLA · May 2010

Re: Dual XW6048

XW should stop selling when you disconnect grid. You must be connecting ACout back to main panel.

MichaelB · May 2010

Re: Dual XW6048

RCinFLA wrote: »

XW should stop selling when you disconnect grid.

It does..Then I kill the breaker to AC1 at the panel..
2nd I turn ON the AC Output breaker at the panel on a second pair of breakers..
XW is in Invert mode all the time and begins to produce power on its own.

Another way to visualize it is..my AC Output which normally goes to a dedicated
set of breakers for say lighting and a frig..actually is wired back to my main panel so it feeds the entire home as needed.

This allows me to use 100% of my solar production daily for anything possible
Anything left over will sell back to grid at the meter.

If the grid fails due to local outage the XW self shuts down as it should.
If Im home.. I have to manually disconnect the 400amp knife switch
Then switch off AC1
Then switch ON AC output.

RCinFLA · May 2010

Re: Dual XW6048

Pretty mutated hook up.

If your statement of 625 amps means 625 amp-AH's of battery you don't really have enough battery capacity to run these loads. Even with your PV, an hour of cloud cover and you have hurt the batteries.

Solar Guppy · May 2010

Re: Dual XW6048

I agree with RC, I have 660ah and it wacks the batterys hard when my 3 ton heat pump turns on. If you want to handle startup loads like that you listed you will need a substantially bigger battery bank. A dual XW-6048 will also help maybe support your loads, but not with the batterys you have installed, you need a MUCH larger battery AH bank

MichaelB · May 2010

Re: Dual XW6048

Solar Guppy wrote: »

I agree with RC, I have 660ah and it wacks the batterys hard when my 3 ton heat pump turns on. If you want to handle startup loads like that you listed you will need a substantially bigger battery bank. A dual XW-6048 will also help maybe support your loads, but not with the batterys you have installed, you need a MUCH larger battery AH bank

Agreed..yes I do but Im building up the system over a couple years..
Last year was the base system and testing to find what I actually need or want to do.

This year now, Im considering doubling up the inverters IF I am to support
one of the two geo units, well, basic lighting and frigs.

Once a second XW is online I can then add more solar panels.. Move from 6K to 9K or 12K of Solar PV over another year. Im guessing with phantom power draw & Geo+Well I would expect to see the two XW unit running about 3.5K each

Adding batteries is what Im doing slowly since they are costly..
I am using 12V Marine 875A 125AH in series/parallel. I have checked with Xantrex and Johnson Battery for my configuration and it was blessed by both.

Currently I have 5 banks of 4 batts. This gives me 625AH now at 48VDC.
I have to add 4 batteries at a time. No biggy. I will probably stop around 1000AH or slightly over. Im considering recharge time if the grid is down for days
plus optional Generator if I go that route.

When the Geo unit is online say heat of summer time..Total run time on that unit is around 7hrs total per day. Usually its on for 15min blocks or less.

Also I will add that during summer months I have a dedicated 4in pvc pipe forcing air conditioned air from the homes basement into the bottom of the inverter and also into the battery box so they dont go over 85'

mike95490 · May 2010

Re: Dual XW6048

MichaelB wrote: »

......

Geo unit after about 30sec cracks open the water loop valve which triggers the well pump to spin up ( 220V 14amp deep well ) XW now shows 2300watts load.

Geo unit 4 seconds after opening water valve spins up compressor.. XW goes to 6100 load for about 1 second then shuts down...

2300W = 48A @48V
6100W = 127A @ 48V from your bank is a killer

Maybe low battery voltage is the problem ?

Any way to get a LARGER pressure tank, to buy you some time before the well pump kicks in ? What size is the current pump, would a smaller one work - maybe this is the generic one the well dude had on the truck, and is overkill.

Modify the well pump to a 3 wire unit, a little less starting surge, or even a 3 phase with a slow (5 min) ramp up to full power

MichaelB · May 2010

Re: Dual XW6048

RCinFLA wrote: »

Pretty mutated hook up.

If your statement of 625 amps means 625 amp-AH's of battery you don't really have enough battery capacity to run these loads. Even with your PV, an hour of cloud cover and you have hurt the batteries.

Actually Im using a midnite solar e-panel..its a very clean setup. Nothing explosed except the battery cable, Nothing like the crazy things I see others connecting.

MichaelB · May 2010

Re: Dual XW6048

mike90045 wrote: »

2300W = 48A @48V
6100W = 127A @ 48V from your bank is a killer

Maybe low battery voltage is the problem ?

Any way to get a LARGER pressure tank, to buy you some time before the well pump kicks in ? What size is the current pump, would a smaller one work - maybe this is the generic one the well dude had on the truck, and is overkill.

Modify the well pump to a 3 wire unit, a little less starting surge, or even a 3 phase with a slow (5 min) ramp up to full power

Batteries show at 53v on the xantrex console and they are less that one year old.
I have not held a meter while on standby to them.
A test I do is to run the basics in the home at night on full battery. XW is putting out 2.5k and will run about 6hrs. This matches what Xantrex battery calculator says.

The well pump is a Goulds 4" 3wire ITT variable speed pump controlled by a Goulds BF30 computer controller to maintain pressure without a tank. Yes a tank might buffer my start up time but I would have to add it. My geo needs 12.5gpm at 30psi and the pump supports that and more if need be.

MichaelB · May 2010

Re: Dual XW6048

Another that that crossed my mind..
The XW Grid support breaker size is set to 27amps which internally regulates
how much the XW will send out in production power.

I would bet if that could be given some grace more like 30...
the XW might make it past the startup surge.

Solar Guppy · May 2010

Re: Dual XW6048

Your XW-6048 via the SCP will give you the fault code, either your overloading the inverter on the output or your going to get a low-voltage cut-out .. The surge is what matters and is hard to capture with a DVM what how the bank is reacting.

Your need to add batterys before you add another inverter, 600ah is about the minimum needed for a XW-6048 if your pushing it to the limits, adding another XW-6048 will just make things worse

Also, adding strings in parrallel is a problem, more than 3 strings and you will get into balancing of the strings ... these systems don't work well scaling up as you have funds

MichaelB · May 2010

Re: Dual XW6048

Solar Guppy wrote: »

Your XW-6048 via the SCP will give you the fault code, either your overloading the inverter on the output or your going to get a low-voltage cut-out .. The surge is what matters and is hard to capture with a DVM what how the bank is reacting.

Your need to add batterys before you add another inverter, 600ah is about the minimum needed for a XW-6048 if your pushing it to the limits, adding another XW-6048 will just make things worse

Also, adding strings in parrallel is a problem, more than 3 strings and you will get into balancing of the strings ... these systems don't work well scaling up as you have funds

I can do another test in the next day or two to see if the scp logs anything.
I browsed back to one of the test dates but nothing was in the scp for that date.

Batteries. I have recently heard of the strings of 3 and was also told to contact
the battery mfr and find out what they recommend for my spec type.
I can also find out tomorrow.

I was also informed by xantrex yesterday that the supplied 2/0 - 10foot battery/inverter cable needs to be changed to a 4/0. Seems either something
was changed after I purchased my system or a part was mis-engineered when the system was put together. This also might be the weak link

MichaelB · May 2010

Re: Dual XW6048

I called xanterx support and gave him my situation.
Apparently the 6048 will surge to 12K for 20sec using the batteries before shutting down. 600Ah is the min..recommend more like 1000 as a min.

Since its crashing around 6k and that I have only 625Ah I need to add more batteries and also upgrade to 4/0 for wire runs longer than 1 foot.

He was not aware of any battery string of 3 being an issue but that might still fall back on the battery mfr.

So I guess tomorrow Ill have a welding shop make up my 4/0 cables and swap
plus add at least 1 to 2 more battery banks.

System2 · May 2010

Re: Dual XW6048

MichaelB,

We have read your comments in regards to your WaterFurnace. We do not have a background in solar energy; however, we would be interested in offering our assistance. Is this a project you are working on with a contractor or on your own? Please provide your model and serial numbers so that we may look into your inquiry further.

WaterFurnace International, Inc.

Dual XW6048

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