Setting up Gen Auto Start on series connected Trace SW4048's

Darkman · October 2012

Hello All!

Thanks for looking at this post.

I have an off-grid solar system comprised of 2 - Trace SW4048 inverters connected in series. I have recently installed a 14KW Kohler propane backup generator and connected it to my inverter system. I am attempting to have the inverters automatically control the generator through the Gen Auto Start feature on the inverters. At this point, everything is hooked up and I can manually start the generator from either of the inverters control panels. That in itself is a great blessing, since I will no longer have to dress up and hump outside in the dark and cold to turn the generator on and off. Also I have switched from gasoline to propane...much easier on the pocket book.

I have the full manual for the inverters and have gone through all of the relevant settings from battery charging to generator setup.

My first question is....Is there anybody out there with a similar setup that is actually working with the gen auto start on their own system? I have looked over all of the forums here and have seen a couple of people posting questions similar to mine, but nobody seemed to provide a helpful response to figure out what the problem might be.

The issue is this. As mentioned earlier, I can manually start the generator from either of the inverters. I have set the auto start parameters to numbers that seemed to make sense to me, based on all the reading I have done. Currently one of my inverters is not connected to solar panels, so the generator is the sole source of power to the second inverter. At this time I'm not putting any load to speak of on that inverter, but the inverter itself is slowly drawing down the battery bank. I am hoping that I can have the auto gen start keep the batteries in condition on that inverter until I get the solar panels up for it, but so far I have not seen the system auto start the generator from either of the inverters.

I allowed the second inverter to run the batteries down below the threshold levels I set, and the only response I got from the inverter was a generator sync error, but I don't believe that the system actually ever tried to start the gen. The first inverter hasn't discharged near any of the parameters set to trip the generator, so it hasn't tried to start the gen as far as I can tell.

Does anyone know of a reliable way to set up the inverter so that the auto gen feature can be tested beyond the manual ON switch? Are there any special parameters or ways of configuring the inverters that I may be missing? Any help or advice is greatly appreciated. I will do my best to answer any technical questions that need to be asked.

Thanks...

Cariboocoot · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Welcome to the forum.

There are people here who still run the venerable Trace SW inverters. Hopefully some of them have autogen start functions.

I do have a question which might help provide the over-all answer: you have one generator's AC output connected to two inverters' AC input?
If so, this may cause the sync error. Try it with the gen connected to one inverter only (for AC and start control). Once you get it working off one then maybe it can be set to work off both. (There is something familiar about this scenario which makes me ask.)

Darkman · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Cariboocoot wrote: »

Welcome to the forum.

There are people here who still run the venerable Trace SW inverters. Hopefully some of them have autogen start functions.

I do have a question which might help provide the over-all answer: you have one generator's AC output connected to two inverters' AC input?
If so, this may cause the sync error. Try it with the gen connected to one inverter only (for AC and start control). Once you get it working off one then maybe it can be set to work off both. (There is something familiar about this scenario which makes me ask.)

Thanks for the response.

The generator inputs on both inverters accept 120VAC. The Kohler gen outputs 240VAC, so I have one side of the hot line from the generator (120VAC) going to each inverter separately. The trigger wire that tells the generator to turn on is parallel connected to both inverters, so either inverter can start the generator...that has been tested and is working as long as I manually turn the generator on from the inverter/s.

I may go ahead and try your idea anyway...just to see if one of the inverters alone will do what I expect.

Ralph Day · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

I think you have to master/slave the two inverters...one controls when the gen comes on. Is the neutral from the generator output connected to the neutral of both inverters?

Your setup sounds strange for 2 inverters in series. Your inverter output is 240ac, correct? They really should be master/slave configured to avoid conflicts.

Solar panels are not "connected" to your inverter, or shouldn't be at least. Both inverters should be getting 48vdc from your battery bank and charging it too through that connection.

I only have one sw4048, and it's enough to configure and work with. Never used auto gen start, only initiated by me.

Ralph

Vic · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Hi Dm,

First, I do not meet your qualification screen.

BUT, I do not understand your system configuration. It is quite customary for a pair of inverters to be Stacked, by using a Stacking Cable. That is the case for the SW+ Xantrex successors to your inverters. And, it is also customary for these two inverters to share the SAME battery bank, and in such cases, the PV input is connected to a Charge Controller, which charges the BATTERY, and does not really run the inverter. The way you stated the setup you have, it almost seems that the second inverter has its own separate battery bank.

I would think that you could set the genstart voltage to some fairly high value like 50 or 51 volts for testing purposes.

I do not want to pick at your setup, but am just a bit uncertain about the setup, in general. I will be no help on the details of the AGS functions. These inverters may have a load sharing function that starts the genset for heavy loads, but if so, that will have its own set of parameters which may take a while to figure out.

Am fairly certain that someone here runs AGS on Trace SW inverters. Vic

bwoltz · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

The generator sync error means that you either have a frequency or voltage issue with the Genset.. I don't have the dual setup but have been running a 120V single SW4024 for the last 15 years.. I've had sync errors usually caused the the generator frequency. Genset is an old Onan NHD that has a mechanical only governor..

Anyway I don't suspect that you have my problem.. Not sure what it could be in you case but there are some places I'd look.. You say the the generator doesn't even start.. This sound to me like AC is getting into the feed side of the generator and when the inverter thinks it sees voltage in the input, it thinks it don't need to start the Genset since it's already running.. It then fails to measure the correct frequency to connect possibly because of noise or phase issues.. One place to look is that the Neutrals on both inverters are solidly connected to the neutral on the Genset. Make sure it's wired per the documents. Even if you think it's correct. Double check. I'd also check the configuration that allows to 2 SW4048s to communicate with each other.. There is an cable that goes between them.. Make sure it's is connected up right.. The manual I have says almost nothing about the dual setups.

If the Genset does start then it may be and issue with the way the phases of the generator are wired to individual inverters or the frequency / voltage of the Genset.. I have a small cooling fan that pushed air out of the generator room.. Helps to load the Genset a little and stabilizes the output voltage..

On issue I had early on was that I run a 4 wire start stop instead of 2.. One thing that would happen is that the genset would connect the start wires then disconnect them as soon as it sensed voltage from the genset.. This became a start issue with me as the start wires would open before the Onan had enough oil pressure to keep running (has and oil pressure shutdown).. The inverter would try to start the Genset and after 3 tries it gave up.. Generator Start Error Definitely not your problem..

I ended up add a delay relay that held the wires connected for about 3-4 more seconds..

Cariboocoot's idea of isolating them is probably good...

Good Luck..

Bruce

Darkman · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Thanks very much for your response. According to the manual for the SW4048, there are several possible configurations that I can play with on these units. The first is a series connection that uses a control cable between the two inverters. This allows each inverter to run separately as a 120VAC power source, but they are synced out of phase from one another so that you can wire them together for 240VAC. This is the configuration I am using.

You can also wire them in parallel as a master/slave system utilizing the same battery bank. It will double 120VAC current, but will not run as a 240VAC system.

Yeah, but this is how the manual instructed me to set it up. Yes, I have 240VAC when combining the output of the two inverters.

I apologize for any confusion with my descriptions. The solar panels go to a charge controller first, then to the inverter. The second inverter is not receiving any power input outside of the generator at this time.

I am attempting to automate the system as much as possible, it will free up my time to do other things...thanks.

Darkman · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Vic wrote: »

Hi Dm,

First, I do not meet your qualification screen.

BUT, I do not understand your system configuration. It is quite customary for a pair of inverters to be Stacked, by using a Stacking Cable. That is the case for the SW+ Xantrex successors to your inverters. And, it is also customary for these two inverters to share the SAME battery bank, and in such cases, the PV input is connected to a Charge Controller, which charges the BATTERY, and does not really run the inverter. The way you stated the setup you have, it almost seems that the second inverter has its own separate battery bank.

I would think that you could set the genstart voltage to some fairly high value like 50 or 51 volts for testing purposes.

I do not want to pick at your setup, but am just a bit uncertain about the setup, in general. I will be no help on the details of the AGS functions. These inverters may have a load sharing function that starts the genset for heavy loads, but if so, that will have its own set of parameters which may take a while to figure out.

Am fairly certain that someone here runs AGS on Trace SW inverters. Vic

Thanks for your reply.
I'll try to clarify things. Essentially I have two independent power systems. Each SW4048 has its own battery bank and will generate 120VAC. They are connected in what the manual describes as a series-stacked configuration. A cable connects the two inverters and shifts their 120VAC outputs out of phase with each other in order to facilitate wiring them for 240VAC output. PV panels are connected to charge controllers and then to the inverter.

There are 4 levels of trigger points that are configurable to auto start the gen. 24hr, 2 hr, 15 min, and LVD. You can set trigger point voltages for each of these time periods in order to auto start a generator.

I will try some higher voltage settings and see if that does the trick. Thanks for your advice.

Cariboocoot · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Not absolutely certain about the SW, but normally series-stacked inverters have to run as one unit not two separate devices. As such they still have a master and slave, and the master controls the functions including gen start.

It is possible to supply two inverters (stacked either series or parallel) from two separate battery banks; there is no requirement to couple the DC for operation. Usually, however, a series stacked configuration will use one battery bank as it functions as one 240 Volt inverter.

Charge controllers' output connects to the battery bank, not to the inverter.

You appear to have two banks with only one connected to the charge controller; the other receiving charge only from the generator.

The curious thing here is that you get the "sync error" message before the generator even tries to start. This would indicate that somehow AC OUT from the other inverter is appearing on the AC IN causing the error. One thing I would suspect is a ground loop problem of the nature of having two neutral-ground bonds in the system; one on the inverter output (at the distribution panel) and the other on the generator output.

Darkman · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

bwoltz wrote: »

The generator sync error means that you either have a frequency or voltage issue with the Genset.. I don't have the dual setup but have been running a 120V single SW4024 for the last 15 years.. I've had sync errors usually caused the the generator frequency. Genset is an old Onan NHD that has a mechanical only governor..

Anyway I don't suspect that you have my problem.. Not sure what it could be in you case but there are some places I'd look.. You say the the generator doesn't even start.. This sound to me like AC is getting into the feed side of the generator and when the inverter thinks it sees voltage in the input, it thinks it don't need to start the Genset since it's already running.. It then fails to measure the correct frequency to connect possibly because of noise or phase issues.. One place to look is that the Neutrals on both inverters are solidly connected to the neutral on the Genset. Make sure it's wired per the documents. Even if you think it's correct. Double check. I'd also check the configuration that allows to 2 SW4048s to communicate with each other.. There is an cable that goes between them.. Make sure it's is connected up right.. The manual I have says almost nothing about the dual setups.

If the Genset does start then it may be and issue with the way the phases of the generator are wired to individual inverters or the frequency / voltage of the Genset.. I have a small cooling fan that pushed air out of the generator room.. Helps to load the Genset a little and stabilizes the output voltage..

On issue I had early on was that I run a 4 wire start stop instead of 2.. One thing that would happen is that the genset would connect the start wires then disconnect them as soon as it sensed voltage from the genset.. This became a start issue with me as the start wires would open before the Onan had enough oil pressure to keep running (has and oil pressure shutdown).. The inverter would try to start the Genset and after 3 tries it gave up.. Generator Start Error Definitely not your problem..

I ended up add a delay relay that held the wires connected for about 3-4 more seconds..

Cariboocoot's idea of isolating them is probably good...

Good Luck..

Bruce

Thanks for responding Bruce.
I agree with you on your assumption about what a generator sync error means. I have seen it with other generators that I have run on this system that were not as stable as the Kohler I just installed. If the gen was running and I got that error, I would be able to check a few items on the meter panel and get a clue about what the problem was. But, since the inverter never started the generator, I have to assume that the error generated was for something else?

As I mentioned in the first post, I can start the generator from either of the inverters right now, as long as I do it manually. That is, go to the generator menu, set it to ON at the inverter control panel, watch the little green light blink a half dozen times and the generator fires right up. Now I just want the inverter to do the same thing without my direct intervention.

Since I am completely off-grid, there is no outside source of AC coming into my inverters until the generator is running.

All neutrals are connected together properly and the entire system is grounded at a single location. The cable between the inverters is brand new and similar to a parallel port connector on an older PC. You can't put it in wrong. I can generate a good 240V signal from the system, so everything is working properly on the power output side of things.

My Kohler generator has a 2 wire start/stop and my inverters are capable of 2 wire for gas/propane, or 4 wire start/stops for diesel gens. Mine is propane.

Thanks for your ideas...

Darkman · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Cariboocoot wrote: »

Not absolutely certain about the SW, but normally series-stacked inverters have to run as one unit not two separate devices. As such they still have a master and slave, and the master controls the functions including gen start.

It is possible to supply two inverters (stacked either series or parallel) from two separate battery banks; there is no requirement to couple the DC for operation. Usually, however, a series stacked configuration will use one battery bank as it functions as one 240 Volt inverter.

Charge controllers' output connects to the battery bank, not to the inverter.

You appear to have two banks with only one connected to the charge controller; the other receiving charge only from the generator.

The curious thing here is that you get the "sync error" message before the generator even tries to start. This would indicate that somehow AC OUT from the other inverter is appearing on the AC IN causing the error. One thing I would suspect is a ground loop problem of the nature of having two neutral-ground bonds in the system; one on the inverter output (at the distribution panel) and the other on the generator output.

Hi,

The configuration I have, as strange as it sounds, is right out of the SW manual for these inverters. Here is a quote from the manual,

"When series stacked, you get twice the power of a single inverter available for operating 240VAC loads, but only one inverter's power is available for operating a single large 120VAC load....A special stacking interface cable is required to connect the series stacking ports of the inverter to ensure the output voltage waveforms of the two inverters are phase synchronized and locked 180 degrees from each other. This allows connection to 120/240VAC generators and utility grids. The 120 VAC loads are split and connected to either inverter. Both of the inverters operate completely independently-except their frequency is locked. They do not operate as a master-slave device as previous inverters have. One inverter can be in battery charger mode while the other is inverting to power an AC load. This independent operation allows many new possible applications and abilities that were previously not possible."

Hopefully that will give some of you a better idea about how this system operates.

I will consider a grounding problem and look into it, but I don't think this is the problem, since I can start the gen from either inverter through the control panels. It just isn't doing it by itself yet...

Thanks...

ChrisOlson · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Darkman wrote: »

Thanks for your reply.
I'll try to clarify things. Essentially I have two independent power systems. Each SW4048 has its own battery bank and will generate 120VAC.
There are 4 levels of trigger points that are configurable to auto start the gen. 24hr, 2 hr, 15 min, and LVD. You can set trigger point voltages for each of these time periods in order to auto start a generator.

You got the same setup I have - assuming you have this gen controller:

Attachment not found.

Your system is not set up right. When you stack two SW-series inverters for split-phase power one is the master, the other is slave. The master is designated as the L1 inverter and it controls the generator. They are NOT two independent power systems. Each one powers one leg of the split phase service, but they both share the same neutral. There are two different stacking kits - one is a parallel kit that syncs the sine waves of both inverters, the other is a ISC-S (Inverter Stacking Control - Series) cable that puts the slave inverter 180 degrees out of phase with the master.

Second point - you can NOT have two separate battery banks for stacked SW inverters. They must both be connected to the same bank.

Get this stuff fixed first - then I'll tell you how to set up the master to auto-start the generator, and what the proper settings are for charging your battery bank. Attempting to get one of those inverters to auto-start that generator right now is only going to cause smoke someplace because you got it majorly messed up being able to control the GRM with two inverters.

Edit:
DC Wiring:
When you wire up stacked SW-series inverters, they must be wired a specific way. The power studs on the two inverters are tied together, positive to positive and negative to negative on the two units. The negative from the bank goes to the L1 (master) inverter. The positive from the bank goes to the L2 (slave) inverter and the DC disconnect goes inline on the positive to the L2 inverter. Failure to wire it up this way will result in a burned out transformer in the L2 inverter if you try to charge the battery bank with it.

AC Wiring:
Make sure each leg of the generator goes to the AC2 input on each inverter. Do not use AC1. Some generators have a bonded neutral (neutral connected to generator frame). This will not work for stacked inverters. The generator must have a floating neutral and the neutral-ground bond is made at the service panel. You can drive a separate ground rod at the generator if you want.

The wording in the manual for stacking two inverters is confusing because they are still master/slave. The only difference from other types is that you can use a 120 volt generator with stacked inverters by supplying 120 volt power from the generator to the L1 (master) inverter. This will allow only the master to charge the battery bank while the slave stays in invert mode.
--
Chris

Vic · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Chris,

You DO know that Dm is using the Trace SW series inverters(?). As you (may) know, the SWs had the AGS function built into the Inverter, and may also differs in additional ways from the SW+.

The two separate batt banks makes me think that possibly the inverters and battery banks are in different locations. May be in error.

Vic

ChrisOlson · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

My bad - but still what is in the Trace GSM for the SW+ is the same thing that was in the SW Series II inside the case. You can't control one generator with two different inverters, nor can you have two battery banks with stacked units. I will quote the relevant part of the manual:

When using inverters in a stacked configuration, the same battery bank must be used for both inverters (on pg 5).

When multiple inverters are used with a generator, only one inverter can be connected to the generator via the GRM and is designated as the "master" or L1 inverter (on pg 16).

Yes, there are some other differences between the Series II and the SW+ - the SW+ has
-double the surge capacity of the old Series II for 5 seconds on the SW+ 4024, can operate at 3x rated load for 11 seconds, 2x rated load for 5 minutes, 1.2x rated load for 30 minutes
-there is no difference in surge capacity between the SW+ 4024 and SW+ 4048/5548 -the 48 volt models can operate at 2x rated load for 11 seconds, 1.5x rated load for 5 minutes, 1.2x rated load for 20 minutes.
-non-volatile memory
-field upgradable flash memory
-no temperature de-rating for rated power output up to 104°F ambient
-totally different three-level menu
-the battery temp sensor plug is on the DC side
-GSM and ALM modules optional instead of being included in the inverter

Magnum Energy will be coming out with a new inverter called the MSH4024RE with dual AC inputs @ 60 amps each, and generator load support, which currently only Xantrex has ever had. The new MSH4024RE is Magnum's version of the venerable Trace SW+ series, as it will also have separate generator start, remote, etc.. The first ones that go into production will be 120 volt only, and are non-stackable.
--
Chris

Vic · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

OK, Chris,

Yea, believe that the GSM function twix the two are quite similar. Very few users of Trace/Xantrex SW/SW+ family inverters around here use GSM. I have the provision here, but just do not like to let this stuff run unattended. If we had the severe weather that some folks have, am sure that we would try running Auto-Start.

Nice summary of the SW+ benefits vs the SWs.

Thanks for the info on the Magnum. Seems that they are on a good track. I am quite satisfied with the SW+ 5548s here. Just will be very disappointed when one croaks. Hope MidNite will get around to some inverters.

ChrisOlson · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

I believe it is Robin Gudgel's son (his wife Mary's son, anyway) that was one of the founders of Magnum Energy. This is a brief history of how some of the best off-grid equipment in the world got designed and built:
http://www.hardysolar.com/inverter/inverter-history.html

Yes, Magnum has some really nice units. I'm pretty excited about their new load sharing inverters, and when they build one that's 120/240 split phase I will probably pull out my Xantrex SW+ 4024's and replace them with a new Magnum setup. In the mean time, short of a lightning strike, or doing some stupid, I don't know of anybody who can destroy or break a SW/SW+ inverter. They remain to this day the standard by which all others are judged.
--
Chris

Darkman · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Hello Chris and thank you for your detailed response.

I guess the first thing is that I don't have an external gen controller, at all. My SW manual suggests that it is all internal on these units, so is it possible that my system doesn't need this?

After reading through your post, I went back to the manual and re-studied the schematic for setting up dual 4048's and it does appear that both inverters share the same battery bank. This was an obvious oversight on my part, but I have been making changes to the system for the past year and remembered that I originally had all the batteries in a single bank, but found out that I didn't have enough generator to effectively charge the system.

Now that I have a big generator, re-connecting all the batteries into a single bank will work from that aspect.

I have the serial cable for setting up the series-stacked configuration and it is tested and working.

I have also made the wiring changes you suggested and everything is up and running again. I am currently manually running a conditioning cycle with the generator to re-balance all the batteries.

I have set up the battery charging parameters on both inverters based on values I got for these batteries from the Trojan website...so that part should be OK, unless there is more that you know that I haven't learned yet.

Otherwise, I have made some tentative settings for the trigger points pending your input to tell me how best to configure the inverters.

My generator inputs have always been connected to AC2, per the manual.

That should do for now. Looking forward to your next level of advice.

Thank you....

Hawk

ChrisOlson wrote: »

You got the same setup I have - assuming you have this gen controller:

Attachment not found.

Your system is not set up right. When you stack two SW-series inverters for split-phase power one is the master, the other is slave. The master is designated as the L1 inverter and it controls the generator. They are NOT two independent power systems. Each one powers one leg of the split phase service, but they both share the same neutral. There are two different stacking kits - one is a parallel kit that syncs the sine waves of both inverters, the other is a ISC-S (Inverter Stacking Control - Series) cable that puts the slave inverter 180 degrees out of phase with the master.

Second point - you can NOT have two separate battery banks for stacked SW inverters. They must both be connected to the same bank.

Get this stuff fixed first - then I'll tell you how to set up the master to auto-start the generator, and what the proper settings are for charging your battery bank. Attempting to get one of those inverters to auto-start that generator right now is only going to cause smoke someplace because you got it majorly messed up being able to control the GRM with two inverters.

Edit:
DC Wiring:
When you wire up stacked SW-series inverters, they must be wired a specific way. The power studs on the two inverters are tied together, positive to positive and negative to negative on the two units. The negative from the bank goes to the L1 (master) inverter. The positive from the bank goes to the L2 (slave) inverter and the DC disconnect goes inline on the positive to the L2 inverter. Failure to wire it up this way will result in a burned out transformer in the L2 inverter if you try to charge the battery bank with it.

AC Wiring:
Make sure each leg of the generator goes to the AC2 input on each inverter. Do not use AC1. Some generators have a bonded neutral (neutral connected to generator frame). This will not work for stacked inverters. The generator must have a floating neutral and the neutral-ground bond is made at the service panel. You can drive a separate ground rod at the generator if you want.

The wording in the manual for stacking two inverters is confusing because they are still master/slave. The only difference from other types is that you can use a 120 volt generator with stacked inverters by supplying 120 volt power from the generator to the L1 (master) inverter. This will allow only the master to charge the battery bank while the slave stays in invert mode.
--
Chris

ChrisOlson · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Ok, as long as we're on one battery bank and you disconnected the wires from the generator control to one of the inverters, you can designate the "gen controlling" inverter as the "master" or L1 inverter. The other is L2 or "slave".

To test the auto-gen start, first go to the Gen menu and set the cursor on On on the L1 inverter. The generator should start. Move the cursor to Off and shut the generator down. This verifies that the L1 inverter will actually start and stop the generator. Set the cursor to Auto.

Go to your Gen Timers menu and set the warmup time to a reasonable time - 2 minutes is good for most things. If you need generator load support, then you'll set the warmup timer to a shorter interval like 15 seconds (and this assumes you're using a pre-heated generator, or a unit capable of going to full rated load with only a 15 second warmup).

Now scroll thru to the inverter setup menu and go to the LBCO (Low Battery Cutout) menu item and raise the LBCO a few tenths of a volt above your current bank voltage. And set the LBCO timer to a reasonably long time time like at least 15 minutes so the inverter doesn't shut down. The inverter should attempt to start the generator within 30 seconds of bank voltage being below the LBCO setting.

If you get a successful auto-start observe what it does - the AC2 input light on BOTH inverters should be blinking and the Status light should be on. After the warmup time has expired you should hear the internal relays in both inverters click and transfer the loads to the generator. At this point the AC2 light on both inverters should be glowing constant and the inverters should start bulk charging the bank.

If you don't get a successful auto-start, or a successful sync and transfer, then we're going to have to look at what other settings you might have set wrong that is causing the problem.
--
Chris

Darkman · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Thanks again Chris!

You have pretty much confirmed what I thought needed to be done. I am currently running an equalization on the bank to get all the batteries on the same page. I probably won't get to run a real test for a day or so, but tomorrow is supposed to be completely overcast with rain/snow, so I should get the opportunity to run some auto-start tests then. I am running the generator from the inverter control panel and have the trigger wires connected to L1. All is good right now!

I'll post again after I've played with it some....

Hawk

ChrisOlson wrote: »

Ok, as long as we're on one battery bank and you disconnected the wires from the generator control to one of the inverters, you can designate the "gen controlling" inverter as the "master" or L1 inverter. The other is L2 or "slave".

To test the auto-gen start, first go to the Gen menu and set the cursor on On on the L1 inverter. The generator should start. Move the cursor to Off and shut the generator down. This verifies that the L1 inverter will actually start and stop the generator. Set the cursor to Auto.

Go to your Gen Timers menu and set the warmup time to a reasonable time - 2 minutes is good for most things. If you need generator load support, then you'll set the warmup timer to a shorter interval like 15 seconds (and this assumes you're using a pre-heated generator, or a unit capable of going to full rated load with only a 15 second warmup).

Now scroll thru to the inverter setup menu and go to the LBCO (Low Battery Cutout) menu item and raise the LBCO a few tenths of a volt above your current bank voltage. And set the LBCO timer to a reasonably long time time like at least 15 minutes so the inverter doesn't shut down. The inverter should attempt to start the generator within 30 seconds of bank voltage being below the LBCO setting.

If you get a successful auto-start observe what it does - the AC2 input light on BOTH inverters should be blinking and the Status light should be on. After the warmup time has expired you should hear the internal relays in both inverters click and transfer the loads to the generator. At this point the AC2 light on both inverters should be glowing constant and the inverters should start bulk charging the bank.

If you don't get a successful auto-start, or a successful sync and transfer, then we're going to have to look at what other settings you might have set wrong that is causing the problem.
--
Chris

ChrisOlson · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Sounds good - let me know what happens. With a split phase generator and stacked inverters, there's no reason for them BOTH not to sync with the generator unless there's a ground feedback someplace, or a problem with the generator. As far as each inverter is concerned it's just hooked to a normal everyday 120 volt generator. But the L1 inverter that starts the generator is still the "master" because it sends the proper control to the slave thru the ISC-S cable to get it's 180 degree out-of-phase output in sync with the other leg of the generator.

The inverters put out perfect 180° out-of-phase legs. Generators never do. I've seen some generators be up to 5 degrees off. If you have a sync problem initially, the first thing I'd try is to turn off the Main (or inverter disconnect to the loads), disconnect the stacking cable, fire up the gen and see if they both sync then when they are truly separate units. If they do, then you have a problem with the generator.
--
Chris

Darkman · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

ChrisOlson wrote: »

Sounds good - let me know what happens. With a split phase generator and stacked inverters, there's no reason for them BOTH not to sync with the generator unless there's a ground feedback someplace, or a problem with the generator. As far as each inverter is concerned it's just hooked to a normal everyday 120 volt generator. But the L1 inverter that starts the generator is still the "master" because it sends the proper control to the slave thru the ISC-S cable to get it's 180 degree out-of-phase output in sync with the other leg of the generator.

The inverters put out perfect 180° out-of-phase legs. Generators never do. I've seen some generators be up to 5 degrees off. If you have a sync problem initially, the first thing I'd try is to turn off the Main (or inverter disconnect to the loads), disconnect the stacking cable, fire up the gen and see if they both sync then when they are truly separate units. If they do, then you have a problem with the generator.
--
Chris

Hi Chris!

Last night my system discharged enough for me to try the auto start test and it passed with flying colors. Everything worked exactly as it was supposed to! I was able to pump the generator input up to 30 amps and it didn't miss a beat! I am now automated.

I wish to thank you again for your assistance and advice. I think I can take it from here and figure out what my trigger points are going to be.

Take care up in the wilds of Northern Wisc... and stay warm. We moved to So. Col. about 4 years ago from Duluth, MN...so I have a real feel for what you deal with every winter. We are up here at about 7500ft elevation at the base of a mountain, so the weather can get pretty familiar from time to time. We have seen -20F up here several times, but nothing like the months of below zero weather you guys can get. Sorry, I don't miss it much.

Best wishes....

Hawk Phoenix

ChrisOlson · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Hawk - cool!

I don't know how long you've had your system set up, but one thing you may need to look at is a T240 (or similar) to balance the inverters. We use one that's hooked to a two-pole breaker in the Main - it works in reverse and supplies our 120 volt loads. Without it the leg balancing would be horrible and one inverter would spend a lot of its time at 2 kW load while the other one would idle with virtually no load on it (just because of the way our Main is wired and most of the 120 volt loads are in the kitchen and my turbine shop).

The venerable SW runs quite inefficient at really low loads and they run at their peak efficiency at around 500-1,500 watts output (~95-96%). If you have one inverter that's "idling" all the time below 500 watts output, it's not good because the inverter efficiency is probably only 75-80%, and the balancing transformer can help remedy that. Your 240 volt loads are always leg-balanced. It's the 120 volt loads that present the problem in most cases with a split phase system.

Regards,
--
Chris

TheBackRoads · October 2012

Re: Setting up Gen Auto Start on series connected Trace SW4048's

Darkman wrote: »

Take care up in the wilds of Northern Wisc... and stay warm. We moved to So. Col. about 4 years ago from Duluth, MN...so I have a real feel for what you deal with every winter. We are up here at about 7500ft elevation at the base of a mountain, so the weather can get pretty familiar from time to time. We have seen -20F up here several times, but nothing like the months of below zero weather you guys can get. Sorry, I don't miss it much.
Hawk Phoenix

Sorry to see ya leave 'The Land of 10,000 Lakes' (mosquitoes) haha

MiltonAdams · September 2022

Hi Chris,

I have two Trace 5548 in parallel and am now trying to add a 120v generator.

I can successfully manually start the generator. AC2 In Good will blink for ~ 10 seconds and then go unto bulk charging. All is good.
I can successfully use the Gen Menu on the master inverter to turn "On" and "Off" the 2-wire generator. AC2 will blink for ~ 10 seconds. Gen starts. Then it blinks for ~40 seconds and goes into bulk charging. All is good.

But when the Gen Menu is in Auto mode, and I raise my LBCO above my current battery level, (per your description above) here is what happens:

- AC2 blinks for ~ 10 seconds

- Gen starts

- AC2 blinks for ~ 40 seconds and turns off Gen. I would have thought it would go into bulk charging.

- About 30 seconds later, the cycle repeats this loop until I manually put the Gen Menu in Off mode.

Any idea why the Auto Gen mode will not go into bulk charging mode?

Thanks.

BB. · September 2022

Welcome to the forum MiltonAdams,

Chris Olson has not been around for ~8 years now... And I don't know of any contact information for him.

At this point, I would suggest starting a new thread/discussion with your questions and go from there. This a 10 year old discussion and it is best to start over with your Q&A for your system.

Sincerely,
-Bill "moderator" B.

Setting up Gen Auto Start on series connected Trace SW4048's

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