Using excess solar on xw inverter/charger ac1 output? Off grid to opportunity load

Snowyverdure

Was looking at upgrading my off solar system to xw or sw. Cool ags gen support components and heavy duty... But tough to use excess energy. Aux port can't be set to float etc... The xw inverter charger ac1 grid sell feature seems interesting using enhanced interactive mode so battery charges and sells all the excess. Could I rig this port to heater/fans, etc. as a opportunity load. It looks like may have to feed a couple watts to aux1 port from inverter with one way diode, and fuse so it thinks there's power to sync with so it feed the heater load? Or is there a better way to use the excess with the conext system? Only have a scp scc at moment

Snowyverdure

Or a better way to divert all the excess and still maintain the best battery charge rates. I know outback and midnite have waste not. And can buy pwm diversion charge controllers...

Vic

Hi Snowy .. Welcome to the Forum,

The Context SW Inverter/Chargers seem to have had a number of teething issues. Some folks seem very unhappy, and others not so unhappy. These inverters seem to have a lot of bang for the buck. If the Idle loss (Tare loss when the inverter is unloaded, but essentially always there when the inverter is running), the SW line seem to have very high Max Idle power specs -- about 1 kwh per day.

The Context XW inverters seem to have a number of frustrating BUGs when they are Grid-Interactive. There has been an "Upgrade" to XW Plus (or similar), but one report was that this was just an exterior paint color-change.

Schneider seems to want to essentially NEVER improve the Firmware in their products, regardless the number and magnitude of the BUGs ... and they seem to also never do any firmware updates of their inventory. It seems quite common for very old product to be shipped to customers when they buy "new" Schneider units.

Updating the FW in the field may have become less tedious, with the advent of their ComBox, which may be able to do updates ...

Am not a great fan of Schneider products. Please consider your purchase very carefully, and ask questions here about all of the many subtle details that you may encounter with Schneider products.

EDIT: BTW, if you have not seen this discussion about some ins and outs of the ComBox:
http://forum.solar-electric.com/forum/solar-news-reviews-product-announcements/solar-information-links-sources-event-announcements/20413-conext-combox-firmware-update-released

FWIW, Good Luck, Vic

SkiDoo55

You would need a "Stable voltage and frequency" on AC1 input to get it to sync. The AUX outputs can only take about 250 milliamperes, basically enough to drive a relay at 12 vdc. Not any vac hooked to it you will burn stuff up. Those AUX outputs can be set at various logic levels, High/Low battery voltage, exit of bulk, exit of absorb, etc. should be able to set those with SCP. Could figure out what works and control VAC loads thru relay on the AC output/Load side.
I am on grid so a different situation, but with the XW set to grid suport/Sell and ZanBus connected to the XW MPPT 60-150, I get a full battery charge cycle and it supports loads on the output and sells back to grid any surplus power. I does suport AC coupling with my 2 grid inverter but have not had the opportunity to try that function out. I am happy with all of my Xantrex/Schneider equipment, that I have, all inverters and charger operate as advertised, yes took awhile to get firware on ComBox fixed to show combination of XW and GT/TX grid to display correctly but it was working and talking/controlling all device connected. I am aware of others that have problem with there equipment so may not be correct for everyone.

Vic

One issue that I've had with the Schneider XW line of products, is that the Aux functions are profoundly stunted. Just checked, once again, the XW Inverter and the SCC Charge Controller (CC Manuals), and, there STILL appears to be no ability of the CC or inverter to signal that it is in Float, and therefore, excess power is probably available for Opportunity Loads.

The venerable MX-60 CC does have this function ... it was designed about 15 years ago, the OB FM CCs do have this function, the MidNite CCs do have this function. Schneider does not care at all, whatsoever, about those who need this function ... could not care less.

The Outback MX-60, and FM CCs as well as the MidNite CCs all have a PWM output on the Aux terminals which will help meter the excess PV (and perhaps Wind power) to a Dump load, like a Water Heater, etc. Schneider appears to have no interest in users who want these functions.

The XW SCC-150 appears to be a uninspired, dated, marginally-functional CC, IMO ... I bought the SCC in 2010, and it came with very BUGGY Firmware ... Schneider would not do anything to update the old, dated, stale, BUGGY firmware ... it sits on the shelf, as a reminder of just how poor is Schneider's customer "service/support" Hope the old Xantrex SW 5548 inverters, here, keep on trucking, as would hate to have to be 'forced" to buy any other Schneider products FWIW YMMV, so on, Vic

Snowyverdure

Thank you for the replies. It does seem like ob and midnite have nice charge controllers for excess power thru pwm aux port then put in a ssr relay then to load. All the companies seem a little buggy? Having the xw inverter ac1 port dump all the extra power to loads at ~115 or 220volts, that's not used for charging seems nice. But can it be done off grid? Ssr Relays on pwm aux on midnite don't dump all the extra like xw ac1 port may be able to supply opportunity loads. The xw scc charge control manual says you can't use absorb and float to turn on relay? The screen on the scc doesn't list it as well? Lots of cool features with charge controllers and equipment these years! Vic i see you use 48 volt bank. Is there a good tutorial on special cautions, grounding negative on battery bank, gfi for 48 volt. Been using 12 volt which grounding bat. isn't required but would like to go with 48v.

Snowyverdure

Please ignore me saying a pwm aux port can run a ssr. Oops

Vic

Snowy..,

There are a number of ways to harvest PV or Wind power that is not need for recharging batteries. For off-grid systems, normally the Charge Controller can manage this, if it is not a Schneider SCC, unless major changes have been made in the past couple of years in the Schneider product line.

So, guess the "AC1 port" you have mentioned is probably selling excess power to the Grid, when the XW inverter is Grid Interactive?

It appears that the XW inverters perform better in an off-grid environments verses being grid-interactive -- I have never had one.

Most products have some bugs. Some manufacturers actually listen to their customers, and strive to fix bugs and improve products with Firmware revisions. Schneider seems to not be very good at doing this.

But, again, the Context XW is probably a stout inverter/charger, and will probably disappoint less ... I mean will probably be happier (as will the customer, probably) in an off-grid system.

No product is perfect ... FWIW, Vic

Graham Parkinson

Hi Vic

Is the " uninspired, dated, marginally-functional" Schneider XW SCC-150 charge controller that you bought in 2010 the same as the "new" Schneider MPPT 60 150? (Part number 865-1030-1).

I've been thinking of purchasing a Schneider XW system for off grid use and am surprised to realize from your post that their charge controller has no Aux outputs that can control a dump load.

I wonder if their fancy (and pricy) battery monitor has an aux output that signals when excess power is available, based on battery state of charge?

I may do the same as you and marry an XW system with a Midnite Classic!

- Graham

Snowyverdure

From what I understand it does have one aux port to control relays. But have to set voltage, temp, etc. to trigger it unless you get creative. Such as using an xw ags to trigger starting a relay at float. Or have the float charge volts set at same volts as absorb volts which sounds risky if dump load quotes working. Then have aux set to trigger on just above this setting. When it switches from absorb to float I guess the volts jump briefly. The battery monitor doesn't. Don't we all need junk sitting on the self for good laughs or reminders! Thanks. I just sold a used smaller charge controller on ebay. First time ever selling on there. It sold well.

Vic

Graham Parkinson wrote: »

Hi Vic
Is the " uninspired, dated, marginally-functional" Schneider XW SCC-150 charge controller that you bought in 2010 the same as the "new" Schneider MPPT 60 150? (Part number 865-1030-1).
- Graham

Hi Graham,

I do not recall the Part number for the SCC that I bought in 2010. Believe that it was called a Build Three, but this is probably just a production Lot number. Believe that Schneider builds (in China) fairly large numbers of units per production lot. This is probably what leads to them having a lot of product in inventory that is "stale". And, for me, since there are NO other XW components in my system, the added cost of buying additional doo-dads to allow updating the old, stale, buggy Firmware that was shipped in my XW SCC makes no sense. And, unfortunately, at the time of purchase, the SCC manual did not state that additional, extra-cost hardware was needed to update the FW.

Snowy..,
First, forgot to comment on Grounding the negative side of the 48 V battery banks ...

Grounding is very specific to the exact installation, and also to the guidelines set by Inspectors of the system. For systems here, the AC side of the inverters are bonded to the ground rods, and there is a separate largish # 4 AWG cable that connects the ground rods to the battery negative in a DC Conduit box for the system. We do NOT use any GFIs on the DC side of these systems.

The SCC's Aux output can be set to trigger on Battery voltage, some temperatures, and PV voltage, IIRC. according to the Manual for the SCC, that I downloaded yesterday. But it still appears that the SCC lacks any function that indicates that the CC has transitioned to Float. There could be work-arounds for this. BUT, this important function for off-gridders really should be in the CC, It would be profoundly simple to implement in the SVV firmware, and amazingly simple to explain in any documentation. But Schneider appears to care nothing about this segment of their potential customer base.

The main reason for the above WHINE is really just a FYI. Schneider can make good products, but if one is expecting updates to the function of their systems, even to fix glaring omissions and/or to fix bugs, the wait may seem to be eternal.

Opinions, YMMV, and so on. FWIW - Vic

Doug Amidon

For the Xantrex XW-60 why not set the AUX on voltage to 29.6 with 0 delay and the off voltage to 29.4 again with 0 delay? Near the end of the bulk charge cycle the dump load begins rapid cycling keeping the voltage in the absorb range while harvesting all available power. A good solid state relay switch would be necessary of course. Has anyone tried this or does anyone see any potential problems? Is the AUX not capable of these rapid on off cycles?

new2PV

Why not use the SOC feature in the xw inverter to trigger what you want to trigger, however you will need the new conext battery monitor for this to work.

MarkP

I have an SW4048 and an MPPT 60 150.  I just hooked up a 119 gallon electric resistance water heater as an opportunity load.  I bought a 12vdc/120vac DPDT relay to turn the heater on and off with.  I use the 12 vdc/200ma from the aux terminals in the MPPT to control the relay.  I am running the heater on 120 vac instead of 240vac because at 120 volts the heater draws only about 1000 watts rather than the 4500 watts it would draw at 240 volts.

I programmed the aux settings to turn on at 55.0 volts (float) and off at 54.0 volts with a 5 minute delay when turning off, so that the battery voltage must remain below 54 volts for  the 5 minute delay time before the load is disconnected.  When there is sun there is sufficient power to run the heater AND charge the batteries.  With less PV power coming in the heater will come on and the battery voltage will get dragged below 54 volts for 5 minutes.  It then takes another few minutes to come back up to get back up to 55 volts.  This is sort of a crude PWM style of control in a way.  I just turned the heater on late yesterday and had a couple of hours to work out bugs before sundown.  Today was partly cloudy with long sunny periods so I got to see the system operate in all situations.  On mostly cloudy days the average battery voltage would be less than the float voltage because it would get dragged down each time it did reach the float voltage but on sunny days like today the heater would come on prior to even reaching absorption voltage and would slow everything down but absorption would still take place normally, reaching float later in the day, exactly like I want.

Elsewhere on these pages there are discussions about how you don't need to reach float every day.  I'm not saying it would be good to never reach float but given a mix of sunny and less sunny days with the heater shutting off below 54 volts it seems like you would be OK with a couple of good sunny days a week.  Remember that on those particularly cloudy days the heater will never come on.

Forgot to say that I calculated 14.5 kwh required to heat 120 gallons from 75 degrees F to 125 degrees.  I figure I got a couple kwh yesterday and another 10 or so today so the tank should shut off tomorrow morning on its own.  I have not actually used any hot water from it yet but during the summer I hope it will provide for all my hot water needs.  How many kwh per day it will draw remains to be seen.  My point is that the last couple of days is a rare situation in that the water heater has run every minute that the battery voltage was above 55.0 and then some.  Most days it will only run a couple of hours a day.

t00ls

I have had a xw system since 2008...never had any problems when I used it for grid tie on ac1
power comes in...power goes out

the 60-150 cc works well with the inverter....and yes vic, it does tell you when it is in float.....but it will always be in bulk if you are selling back to the grid

the aux ilary ports on both the inverter and the CC will do multiple task if you know how to hook them up correctly and if everything hits their trigger points

I also have an AGS that I use quite often now ...since I'm offgrid since 2010....the AGS works flawlessly the way I have it hooked up...you can see the discussion here
http://forum.solar-electric.com/discussion/351285/schneider-ags-i-only-have-this-to-say#latest

Dave Angelini

Ditto 2006 Tools. Nearing 100 applications with the XW system.

new2PV

A little bit off topic, but the AUX contact will not work with the time of day trigger, in the XW.  Schneider said it was an oversite.