Demonstration of Generator Support

90cummins

Re: Demonstration of Generator Support

Thanks mike95 I thought that was the case but I had to ask.
Would be nice if it could also accept 120v only input when configured for 120/240.
Looks like I need to find a 24v charger I can run with my EU2000 for extended operation to minimize fuel consumption IF a prolonged outage happens.
I like options!
90cummins

mike95490

Re: Demonstration of Generator Support

90cummins wrote: »

Thanks mike95 I thought that was the case but I had to ask.
Would be nice if it could also accept 120v only input when configured for 120/240....

I hunted on ebay for a couple months to find a transformer to upconvert 120V from a small inverter generator, to 240v so I could charge.

Blackcherry04

Re: Demonstration of Generator Support

mike95490 wrote: »

I hunted on ebay for a couple months to find a transformer to upconvert 120V from a small inverter generator, to 240v so I could charge.

What size did you finally settle on ?? I saw where Cris Olsen couldn't get a Outback FW-X240 ( 4 kw ?? ) to magnetize on a Honda EU2000.

mike95490

Re: Demonstration of Generator Support

Blackcherry04 wrote: »

What size did you finally settle on ?? I saw where Cris Olsen couldn't get a Outback FW-X240 ( 4 kw ?? ) to magnetize on a Honda EU2000.

It's a 3 or 4 KVA, 480V step down/up transformer. Weighs about 90#, and came with free shipping !! I'm using it for a 2Kw inverter genset (honeywell) and it works fine. Look for a while, and every now and then, the largest tear out vendors have something small with reasonable shipping rates.

jpind

Hi. New here. I'm off grid, and trying to figure out the setup for my standby / backup genny support. The main issue I'm having logistically (also because I'm fairly new at this) is the AGS / UPS system. I currently run a 48v battery bank (8 x Trojan T105s), a 3000W inverter (basic, not an Outback or similar), and a Midnite Solar classic 200. Do I have to purchase a completely new inverter with AGS capability, or is there a way to add a module to the system (magnum?) that would sense low battery level and trip a two wire remote generator start through a transfer switch? Then, is there a way to feed this AC power back in through my midnight solar 200 to charge my batteries, since it's capable of handling high voltages?
Seems like this should work in theory, but I haven't found anyone who's done it, and most of the support teams for the above mentioned items are fairly useless. They just want to sell the $3000 package... Any thoughts or advice would be highly appreciated. Thanks!  

jpind

Sorry, I just realized as I posted this that the MS charge controller obviously only handles DC, so feeding an AC current into it isn't a go. Any thoughts or suggestions, or do I have to bite the bullet and spend another 2K on a new inverter / charger like an outback with a MATE? Thanks!

Blackcherry04

A integrated system is easier to work with because of the variables you can program into it.  You didn't say if you have a Inverter / Charger or just a plain Inverter. You could use a VCS ( voltage controlled switch ) It's a relay that you could set a low volt level and a high volt level and control the start and shut down on a generator with a stand alone charger. A charger and the PV controller can both be on the batteries at the same time.

Here is one from the sponsor, you can find them with google also.

http://www.solar-electric.com/catalogsearch/result/?q=VCS-1AL&cat=0

ELYNN4

Hoping to learn more about generator support function, even though this is an old thread.  I have an XW+6848 inverter.  I have a 2200 amp/hr battery bank that I charge with a 9kw generator.  I would like to use the generator support function, but the literature states it is to be used for 5kw generators or smaller.  When I am charging the battery bank at 90amps the generator cannot carry large loads such as a microwave and gets “disqualified “, then is allowed to try again after a few minutes.  Is the generator support function the best way to get the charger to back down the charging rate or is there a better setting on the XW to use?  I would hate to lower the charging rate full time in order to accommodate the occasional high household demands.  I tried the video link above, but the video is no longer available.  Thanks in advance for any guidance folks might have.

mike95490

Read your manual  !!
 You will be adjusting the settings for AC2 which is the generator input.   Calculate about 70% of your generators "running" or "continuous" load, and that is what you use to calculate the AC2 breaker setting in the XW. 
(don't base this on your generators "peak" load - that will quickly kill your generator..)

ELYNN4

I have AC2 programmed to 65% so that the (9kw) generator output is +/- 6,000 watts.  When I apply a 2400 watt load the generator output drops just enough that the XW takes it off line for a few minutes.  My question is would enabling generator support help in this instance or is it better to limit the load on the generator even more.  The manual states that you should not use generator support on generators larger than 5kw because it may start “recycling “ the current.  Trying to understand why this would happen on generators over 5kw and not on generators under 5kw.

mike95490

please check the generator operation.  No way should a 2500w load, cause a 9kw genset to be disqualified by the XW
Either it's more load than you think,  all on one leg - causing the generator to be imbalanced or your governor is not able to function to keep the RPM's at 3600RPM
 And what are the AC2 input settings for voltage & freq ?
 The XW matches sync to the generator and the transfer switch changes when the 2 are synched, so there are no glitches

ELYNN4

Thanks - here is a screen shot of my settings:

The problem occurs when the generator has a load of +/- 6,000 watts charging the batteries.  The household load is typically +/- 400 watts although it can get up to 800 watts.  Overall the system is very evenly balanced, running within an amp or two between the legs.  The voltage runs around 125v on each leg and frequency is 59.9.  The problem occurs when we use the microwave, which is a 120v load - then the load is significantly lop sided and we are getting close to the max output of the generator, which is an 1800 rpm diesel (Northernlights).  The 1800 watt toaster causes the same issue.

I noticed that there is a Generator Support Plus feature, which can help balance uneven loads like these.

Thoughts on using the Generator Support function on this sized generator?

mike95490

Your AC2 breaker size, is really huge, I'd look at that first.  6kw of load is nowhere near 50A
I'd take the AC2 low voltage down to 95V also.

ELYNN4

Thanks, I’ve dropped the breaker size to 35 amps and the AC2 low voltage to 95.  I raised the maximum charge rate to 70%.  We’ll see how it performs on the next charge cycle.  Thanks again.

mike95490

>  I raised the maximum charge rate to 70%
 If you are overloading the genset, why increase the charge rate, you should be lowering it.
Get the AC2 breaker size dialed in, and then start increasing the the charge rate.

  This is a conventional generator, not a inverter generator - right ?  When it's all working, when charging if the toaster comes on, the charger will throttle back till the toast is done

ELYNN4

My bad, I thought the % was tied to the breaker size - I’ve set it back to 65%.  Yes, this is a conventional generator, not an inverter style.  We’ll see if the charger dials back before the generator gets kicked off line - hopefully the 95v setting will buy the charger a little more time so that it can make the adjustment.  

Thanks again for the suggestions/guidance.

ELYNN4

Curious - the only mention of the charger load throttling back when the generator is overloaded is in the Generator Support section.  Does this mean that Generator Support must be enabled before this function will work?

mike95490

ELYNN4 said:

Curious - the only mention of the charger load throttling back when the generator is overloaded is in the Generator Support section.  Does this mean that Generator Support must be enabled before this function will work?

That's something you must try, I have it enabled and it works

Dave Angelini

I missed if the breaker size was programmed to a normal value. I would start at 25 A for AC2. Your system should run fine there. Then go up to 30A. If you have #10 wiring to the genset or it's receptacle is a 30A receptacle, that (30A) is the max setting for AC2.
Stay warm up there! Sent the rain Mike!

ELYNN4

The manual states:

“If generator support is used with generators larger than 5 kW, it is possible for current to recirculate. In this case, the efficiency losses would outweigh the benefit of generator support.”

Since my generator is 9kw, any ideas on how to identify whether current is recirculating?

Thanks - Gen should run through a cycle in the next day or so.  Will report back on observations.

BB.

I am not sure what is "recirculate" the current...

My guess--More or less, the Genset is supplying current to both AC loads and the inverter-charger charging the battery bank... It may be that the concern is that the genset will be supplying "charging" current to the battery bank, while the AC inverter is trying to "support" at AC loads (helping the generator)... So you have the AC inverter-charger both taking energy to run the battery bank, and taking energy from the battery bank supporting the AC output of the genset+inverter.

You would see (for example) the charging block outputting 20 amps into the battery bank and the inverter taking 20 amps from battery to its AC output.

-Bill "my guess" B.

ELYNN4

Thanks - this is a head scratcher and trying to figure out how I might recognize and measure the inefficiency makes my head hurt.

Update on the system:  

I enabled Gen Supp and Gen Supp Plus.  The generator is running now and it is handling the battery charging as well as additional intermittent loads like the toaster and microwave flawlessly.  What is confusing is when I run the microwave or toaster their loads are not reflected on any of the Gateway screens - strange!

It is curious that the output of the generator doesn’t match what’s going to the house and the battery bank.  This is not new, it was doing this before the most recent changes - my guess is that it reflects the inefficiency of the system.

The battery current that’s reflected on the Battery Monitor screen is different than what’s reflected by the Inverter screen

The SCP has yet a different interpretation.

The generator is wired with #6 wire.  I started with the breaker at 35amps and max charge rate at 65%.  I had the Gen Supp set at 25amps.  This setting had the generator throttled back too much.  I changed the max charge rate to 70%, then 75%, but it still had the generator throttled back.  Then I upped the Gen Supp to 27 amps and got the charge rate up where I want it.

It is curious/ frustrating that the changes I make with the SCP aren’t reflected on my Gateway screens.

All in all I’m a happy camper, things are operating very smoothly now.  Thanks Mike, Dave and Bill for your guidance!

mike95490

After you change the SCP setting, reload the gateway interface, when you log back on, it should reflect the new settings.

ELYNN4

Not all of the changes that I made are reflected in the Gateway after reloading it.  I’ll have to check them and add them manually I guess.

I think that the “inefficiency” that they are referring to is the continual “hunting” that the system is doing now when it is charging at the maximum rate that I have set.  With Gen Supp enabled and the max charge rate set for 27 amps the DC current is swinging continuously from 75 amps to 92 amps.  As soon as the batteries hit 95% SOC and the charge rate started to drop the DC amps smoothed out.  I’m going to try raising the Gen Supp amps and lower the Max Charge Rate to see if it smooths out.  I may need to increase the breaker size before it will let me increase the Gen Supp amps.  I’ve attached a screen shot that shows the “fuzzy” current.

Note how the current smoothed out as the charge rate dropped.

Any other thoughts on how to decrease the “hunting” that the system is doing?

Thanks again.

Dave Angelini

Looks to me like it is the genset being stressed at the higher charge rate, or your loads are pulling it down. The bat mon has calibration set-points, are they correct?

 Lower the charge rate some more. What does your AC meters screen AC2 look like?  Stable frequency and voltage?

I would do what Schneider says about Gen support. If you use the larger genset, do not use gen support. 
They are telling you this because it may hurt efficiency, cause the hash you see at high DC amps and not be useful.

ELYNN4

Thanks Dave.

 I don’t think that the generator is struggling as it was carrying the same load just fine before I enabled the Gen Support.  I enabled the Gen Support because the generator could not charge the batteries AND run the microwave.

My current theory is that the Reactive Power window is set too low and it’s not big enough.  It appears that the Gen Supp Amps are limited by the AC2 breaker size - 80%?  With the AC2 breaker set at 35amps the maximum Gen Support Amps is 28.

I’m going to increase the AC2 breaker size setting, limit the max charge rate to 65% as I had before, and increase the Gen Supp Amps to 30 and see if it smooths things out.

I’ll report back on the results.

Thanks again for the suggestions!

Dave Angelini

A 50 amp breaker size on XW AC2 could cause a 9KW genset to trip it's breaker. What size is the gens breaker? I would guess between 30 and 40 amps? Probably 30. Your programmed setting should be equal or less than the gen breaker!

If it works for you great!  Just keep in mind the number one thing not to do is have XW disconnecting its AC2 relay under load.

You can only do that a finite number of times. It is logged for warranty. If they see a smokey colored clear plastic relay cover,
 your warranty is over. Just an FYI. 

Are they smoking Salmon down in Anchorage? I have buddy up near you that says he can smell it sometimes. 

ELYNN4

Dave, I realized that I didn’t answer your questions- sorry.

The voltage was very steady at 123 - 125 volts on both L1 and L2.  The frequency was also steady at 59.9 and 60.

I believe that I have the Battery Monitor set points input correctly- are there any in particular that I should double check?

Thanks again.  We are staying warm- it’s a balmy 5 above and severe clear.  A couple more months and generator season will wind down!

ELYNN4

Update:

Dave called it right - I raised the Supp Amps to the max (28 amps) and reduced the Max Charge Rate to 65%.  End result is amperage flowing in to the batteries is steady and at the same rate as before Gen Support was enabled.  I am now able to run the microwave and toaster without throwing the generator off line.  I have left Gen Supp Plus enabled as well.

Thanks for everyone’s input.