Hello All
I have a 10 kw Northern Lights generator with a "Automatic Voltage Regulator: DST-100-2FAK".
I have the rpm set, the voltage set and the Hz set.
My lights, led's, flicker while charging not intolerable just annoying, also my hardwired fire/smoke alarms go off once every few generator run cycles at random times during charging.
There are 4 dial type adjusters in the AVR.
VR1: Voltage adjuster
VR2: Stabilizer adjuster (differential) Fixation (Gain)
VR3: Stabilizer adjuster
VR4: Volts/Hertz
I have played with #1 and #4 but not the others.
Could the Stabilizer adjusters cause my flicker and alarms?
I can get access to a scope if that is needed for adjustment, however me playing with a scope is a bit like a monkey reading a road map!
Thanks for any ideas
Wade
What are you using for inverters? And how loaded is the generator is it running real close to the 10KW or?
Ryan
The inverters are 2 Outback VFX3648's, so no I am not taxing the generator with them. After my rpm and Hz/voltage tweeks I believe I'm pulling around 4800 watts total for charging, I wish I could get more out of them.
I run some form of resistance for additional load, most of the time heaters, but presently the load is the wife's Christmas lights, yes she has way too many!
The flicker happens with or without resistance all the way up to 10Kw.
Thanks
Wade
It is the outbacks. They do some really weird stuff to the wave form on generators with electronic voltage regulation. boB can explain it better than I can but if you back the charge current down some it will help a lot.
Thanks Ryan
A buddy has a pair of well exercised Xantrex SW5548's that I may buy to separate functions and reduce run time. Unless you guys are going to get an inverter out soon???
I just thought if a tweek helped I'd give it a try.
Wade
Sorry to bump my own old thread but the project mentioned in my thread "fun and games off grid" has brought up a new question about this thread. Also I have searched and posted, on the Outback forum, about the flicker thing in the past and haven't found anything, so if this works it might help somebody else.
I put a Hevi-Duty shielded general purpose transformer model #S5H15S in between the gen and the new to me SW5548's for leg balancing, works great. What would that do if I put it in between the gen and the Outbacks?
Ryan said "It is the outbacks. They do some really weird stuff to the wave form on generators with electronic voltage regulation. boB can explain it better than I can but if you back the charge current down some it will help a lot."
Would the transformer do away with the "weird stuff" from the Outback/gen interaction?
Also I tried backing off on the charge rate by a few amps per inverter with no real change. Turning off the smoke alarms during charging was easier on me than backing way off and listening to the gen run longer.
Thanks
Wade
And I thought only 650 RPM listers with harmonic excited heads made flicker. But my XW syncs right up to it.
Hm those darn XWs have one heck of a battery charger. The wifey doesnt like it when my lister clone is running the lights go up and down :o
I've wanted a Lister for a long time. Used to play with hit-or-miss back in the day and a 1920 Stanley, that was real fun, the Tesla of the time.
I tried running the Outbacks through the transformer as I'm doing with the SW5548's and nothing good happened, but nothing real bad either, it didn't like it though. The flicker went right through and it pulled the input voltage down bad.
On the SW5548's I took off the synch cable and the master still backed off some. I then tried just the master and it seemed to put out almost as much as the slave but neither put out what I have them set at.
In the SW manual, on page 97, it says:
The most significant problem with multiple inverters charging the same battery is the voltage ripple caused
on the battery. This causes the chargers to not reach their full output - two battery chargers on the same
battery may not provide twice the charging rate to fill the battery in half the time. The higher the charger
rate and/or the smaller the battery, the more pronounced this problem would be. The only way to reduce
the problem is to individually cable each inverter and to connect them at opposite “corners†of the battery
bank.
Can anybody explain how I would cable 2 inverters to opposite corners of the same battery? Art work is always good!
Thanks
Wade
Hi Wade,
A number of folks seem to complain about flicker with OB Inverters -- have no experience with them, though.
Fluorescent lights are quite prone flicker, at least the long-tube varieties. VFLs seem pretty immune to flicker.
You do have a stout battery. Doubt that there is much voltage ripple during heavy charging in Bulk. In Absorb, and even EQ, the battery impedance is higher, so voltage ripple might be higher, although then, the charge current is lower, as well.
Run SW+ 5548, stacked, here. Can run more than 175 A charge rates in Bulk. When Vabs is reached, current sharing is less equal, especially as Absorb progresses. While these units do stack, stacking seems to only sync the sine wave of each, but each charger seems to be independent, especially when regulating voltage -- as in Absorb and EQ. This asynchronous current drawn from the 240 VAC input can really disturb some voltage regulators on gensets, especially in Absorb.
When in Absorb, have read that these venerable Trace/Xantrex SW/SW+ inverter-chargers will dump some battery energy back into the AC input source (like your genset), as a voltage/current regulation method or artifact of being bidirectional. My Honda EU6500isa is unable to tolerate this when the SW+es are in Absorb -- this energy dump drags one side of the AV line input from the genset out of regulation, and is dropped by that one SW+, and will cycle like that until I stop the charge, or back off the charge current to some uselessly small amount. This may not apply to your particular situation.
This situation can cause flicker, although would think that with the SWs running as chargers only (ie AC power not passed through from the genset) that there would be less flicker than when using only inverter/chargers alone.
And, it is quite possible that hardwired smoke detectors may well have very cheezy power supplies, that may not behave well with Alt energy power under all conditions -- just guessing.
Just a stream of unconsciousness. You appear to have a very POWERWUL system! FWIW, Vic
Thanks Vic
A powerful system with a weak operator is pretty weak!
I have no flicker or other issues using the SW's as chargers and letting the Outbacks invert only.
I just can't get the Sw's to charge hard enough. I tried them in charger only mode and thought I had it working, both taking 30A on the AC input for about 2-3 minutes, both in bulk with the batteries pretty low, 53V while charging.
Then the master cuts way back, still around 53-54V, slave taking 28A average and the master taking an average of 3A.
So, I try each SW separately and both take 28-30A with no problems. Which is what made me look at the voltage ripple thing. I just can't figure out what Xantrex means by "opposite corners" of the battery.
Wade
Quote from: toothy on February 10, 2015, 05:32:05 PM
....
Can anybody explain how I would cable 2 inverters to opposite corners of the same battery? Art work is always good!
It's to a battery BANK. You need parallel batteries.
Connect inverter A to Bank 1+
Connect inverter A to Bank 2-
Connect inverter B to Bank 2+
Connect inverter B to Bank 1-
Yea, Mike - Wade has a single string of Surrette 4KS25s.
Wade, do you run separate 4/0 cable runs from the battery for EACH SW 5548? This is the basic spec for 5548s, as you know. It would be nice if those runs are 5 - 6 feet in length or less. Realize that you might not be able to keep the length that short with four inverter/chargers.
I have no problem with 5548 current sharing in Bulk, just in Absorb, especially in the later part of Absorb.
Thinking about this ... Good Luck, Vic
And Wade,
Do you have fairly large AC loads on the inverters, that the gensset must carry, when you have this poor charge current sharing?
I manually ramp up the Charger AC current setting from 33 to about 39 Amps (think that the Max is 39 A on SW+es) when the diesel genset is reasonably warmed-up.
EDIT: And do you have the Menu 13 Generator (Input) AC Amps set to Max, 30 A (IIRC) ??
FWIW, Thanks, Vic
Hello Mike,
Here is the whole section on charging with multiple inverters.
BATTERY CHARGING WITH MULTIPLE INVERTERS
The inverters can operate in parallel as battery chargers from the same AC source connected to the same
battery. The AC input terminals and DC terminals would all be in parallel. The inverters will synchronize
individually to the AC source and then connect.
When multiple inverters are connected to the same battery and operated as in battery charger mode, the
settings of the inverters are best set to the same settings. Only when a system is being operated in
automatic generator control mode should staggered settings be used.
The most significant problem with multiple inverters charging the same battery is the voltage ripple caused
on the battery. This causes the chargers to not reach their full output - two battery chargers on the same
battery may not provide twice the charging rate to fill the battery in half the time. The higher the charger
rate and/or the smaller the battery, the more pronounced this problem would be. The only way to reduce
the problem is to individually cable each inverter and to connect them at opposite “corners†of the battery
bank. Keeping the cable size as short as possible also helps.
Since the inverters will all be charging the same battery, one inverter may taper off first and finish the bulk
stage before the others. When a single inverter has reached the float stage, it is best to turn off the
generator at this time. It may take a longer period of time for the remaining inverters to reach the float
stage. Running the generator to only power an inverter that is float charging is very inefficient and should
be avoided.
If multiple Battery Temperature Sensors are installed, ensure they are all connected to the same location
(battery). This will also help prevent one inverter from tapering off first.
I didn't see anything about parallel batteries it even mentions the same battery in the begining. I just figured whoever wrote the manual had an idea I had not grasped.
Thanks
Wade
Vic,
I am under 6 feet of 4/0 from both inverters.
I have no AC loads on the gen or the SW inverters. All house loads are being supplied by the Outbacks.
I am using the SW's as glorified battery chargers with out any bypass from the gen.
I did buy them used so who knows, but my buddy runs the Fox Island resort out in the bay where they have been since new and he never had any known issues. They were charging the same exact bank.
Speaking about fluorescent flicker did you know you can adjust gen rpm with a fluorescent light bulb?
http://www.sailnet.com/forums/gear-maintenance/38029-diesel-rpm.html
I didn't try that method I bought a pretty good meter.
Thanks for your ideas
Wade
Well, I can't seem to get them to charge together and hard. Master still dropping to next to nothing early in bulk.
I think I'm going to try an EQ starting at 48-50V and see what that does. Unless somebody thinks it a bad idea?
If that doesn't make it charge hard it may be Craigslist time and live with the Outback flicker until the crew around here gets the be all end all going.
Wade
So the SWs are purely battery chargers right?
So how I would do it is wire them each up to a Leg of the genny:
SW1 to L1
SW2 to L2
and NO stacking cable. Now they have no idea each other is there and should charge up to there limit or the capability of the genny. If one is backing off I can only assume a few things:
1- it thinks the battery is full (Check the voltage at the studs on the XW when its charging hard maybe there is a voltage drop issue)
2- some how its being back fed and not liking it
3- There is an issue witht he actual SW (Is it always the same one that backs off?)
Thanks Ryan,
Yes chargers only.
I had them wired SW1 to L1 and SW2 to L2 and didn't like the L1 to L2 imbalance but the SW's acted the same as now. I installed a transformer to balance the lines and it seems to work great.
I removed the stacking cable and the results are the same.
I'll do some more checking and report back.
Thanks
Wade
It works!!
I had a spare blue Midnite temp sensor plugged into the master Xantrex and that was throwing things off.
Probably too much information for that old white box to handle.
I had my input "A" set to 35A and it was only putting out around 30, so I hope when I raise the input limit to 39A I'll be able to get a bit more out of it.
This should take care of my Outback flicker and up my charge rate.
Thanks for all your ideas and help.
Wade
Yes the TRACE SWs use a different ohmage.
Hi Wade,
First, from an old post on the previously-great wind-sun forum here is what boB mentioned about the older Trace/Xantrex SW Inverter/Charger BTSes:
"Re: Resistance Values of RTS/BTSs ?
The old Trace/Xantrex BTS's were 100K at 25 degrees C and are NTC. i.e. resistance goes down with temperature.
OB is also NTC and is 10K Ohms nominal at 25 C.
boB"
The NTC small Thermistor should not be more than about $0.75 (or so) from DigiKey or Mouser.
Have not looked. Then one just needs some cable that CAN be somehow connected to a four-pin Phone connector. Will have to look to see which of the four pins that the Thermistor uses - would guess that it is the center two.
Will try to look around at several Solar Resellers to see if any have old-stock T/X BTSes.
EDIT: Poked around a bit, looking for old-stock T/X BTSes, and found none.
DIgiKey does show a disc-type Thermistor for about $0.79 at quantity one. The main question is what current is flowing through this thermistor, or, really, what SHOULD be the power rating of this part:
http://www.digikey.com/product-search/en?pv867=17&pv976=45&FV=fff4001e%2Cfff80044%2C1140209%2Cd880006&k=thermistor&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25
I have no financial interest in DigiKey or Mouser Electronics, or TDK for that matter ...
All FWIW ... forgot to mention this in the PM exchange. Good Luck! Vic
Thanks Vic
I have the 100k thermistors on a watch list on fleabay or amazon, but haven't gotten around to buying them yet. The sun has been shining and the wind blowing so the boss says she wants flooring more than BTS's, sometime I just don't get their priorities!
I'm pretty sure your correct about it being the center 2 wires, I believe boB said that somewhere.
Thanks for the thought
Wade
OK Wade,
Temperature compensation is important. But, with Inverter-Chargers it may not be as important as it would be from the CC. And you should be coming out of the Winter doldrums, so hope that you will need less generator run time, and much more PV charging ... seems to me.
Good Luck, Vic