Generator for temporary charge

FROZEN · November 2014

Hello,
I have a question involving the connecting of a 3000w Honda generator to my Trace SW4024 Inverter. Days are short right now and I need to assist my panels in the charging of a 24V battery bank.

I know that ideally I want to get the auto start set up to take control as needed, but for now I would like to monitor the levels and just run the generator manually. I don't know if i can simply connect the generator to a separate breaker/ fuse and then on to the inverter where I would have adjusted it for generator battery charging with the appropriate values? Is there more to it? How does the external Charge/Load controller handle the power coming through this way? Any diagrams of the proper connection to give me a visual would be great?

System was purchased used a few years back, I'm guessing the batteries are on there way out. I measured ~27.32VDC volts at noon today at the disconnect and ~29.3VDC at the array.

8 75W panels
16 6V trojans: Deff more battery then panel right now.
Trace 4024 Inverter
Trace C60 Controller

Any experienced help is much appreciated, let me know if I can be more descriptive.

Thanks

scrubjaysnest · November 2014

Re: Generator for temporary charge

As a newbie you have me confused...an inverter converts DC to AC power; where as a converter does the opposite coverts AC to DC. Now I am also not familiar with the Trace SW4024 either but normally you just connect a charger to the battery bank, plug it in to the generator and turn the charger on and if you can set it to the desired bulk, absorb, and float voltages. From what info I can find the trace is strickly a DC input 24volt) and AC output so it can't charge your batteries unless I missed something.

BB. · November 2014

Re: Generator for temporary charge

Many of the off grid AC inverters we see around here are actually Inverter+Charger units (combined function). So they can take AC power in from utility/genset and use it to power the AC loads and charge the battery bank at the same time. For the old Trace SW 4024:

Designed to provide homes with a completely independent power supply, the SW 4024 offers sinewave, utility grade output power, high capacity battery charger, high surge current ability, and easy installation. The SW 4024 inverter/charger can be configured as a stand-alone unit, work in conjunction with your generator to handle loads too large for the generator alone. With the use of the GTI option, it can act as utility interactive inverter, sending excess power back into the grid. When the utility fails, the SW 4024 instantly supplies AC power to critical loads. When the utility power returns, it can automatically recharge your batteries in preparation for the next power interruption

-Bill

Mountain Don · November 2014

Re: Generator for temporary charge

Trace SW inverter/charger user manual link

FROZEN · November 2014

Re: Generator for temporary charge

Thanks for the reply's. I have gone through the manual and read on what the settings are needing to be and what not, my questions were not entirely answered though, unless I missed something. I was unable to discover what the procedure is for connecting to the panel; AC HOT IN 2 from the source (generator), but i am not confident on the start procedure when in a manual start config. Was hoping someone else has needed to temporarily connect to their SW2024.

Aslo, I am planning on connecting to the 20A 120VAC outlet and need a proper method for connecting to the inverter. I know this system was operated with a generator previously and the owner used a disconnect panel in between, but I am not sure of his method, nor can I ask him for input, and his installer was not worth while either.

So what is recommended for the hookup, the generator has its own 20 breaker on the outlets, but i am not sure what to do at the inverter for a disconnect and how to size the breaker/ fuse properly?
I can simply directly connect the generator to a power strip with the essentials plugged in and maintain temporarily but would like to charge the battery bank at the same time. The Honda eu3000is has plenty to go around for my simple cabin.

Thanks!

westbranch · November 2014

Re: Generator for temporary charge

I always start my generators without a load, until warmed up for a minute or so in summer longer in winter, depending on ambient temp, get it running smoooooothly then connect the loads, so you will need some sort of disconnect be it a male plug in or a real switch...

hth

Blackcherry04 · November 2014

Re: Generator for temporary charge

Sometimes I set these and use a double breaker and break the hot and neutral from the generator. You can run a power cord from the generator to the box and then on to the inverter's AC2 input.

http://shop.pkys.com/Blue-Sea-Systems-3131-Surface-Mount-Enclosure-for-two-Circuit-Breakers-_p_2727.html

As far as the procedure to connect the generator to the inverter goes, start the generator and flip the breaker on and the inverter qualifies the power and makes the transfer ( after 10-15 seconds ). You need to set the input amps breaker size on the inverter to match the output of the generator. When you want to stop the Generator, cut the breaker and stop the generator.

Most people have some kind of a sub panel for the inverter output with breakers for the circuits. I guess you could rig up some kind of a box with plugs.

Added : without two cocktails

The Trace uses a " Power Share " scheme on the Generator input. Once you set the incoming breaker limit to say 20 amps it will try to balance the amount of power it allows the charger to take. At about 18 amps it will cut the charger back to keep the over-all draw below 20 amps charger and pass through to loads. You also have the option of turning the charger on and off. You can limit the charger amp draw manually with the Max charge amps.

The Inverter also has "Generator Support " on the AC2 input, nice to have.
.

Vic · November 2014

Re: Generator for temporary charge

FROZEN,

The Honda generator should be connected to the AC2 input of the 4024. If the Honda 3000 is an Inverter generator -- EU3000is, or similar, it could also be connected to AC1, the Grid Power input. You may not absolutely need a breaker at the inverter, as, the generator has its own breaker (as you noted).

If the Honda is not an EU model (which is 120 VAC only output - if you are in North America), it MIGHT have 240 VAC output (unlikely for a 3 K genset), connect only one hot, and the Neutral of the output to the 4024. There are connection schematic diagrams in the 4024 manual. Most small portable generators will not have their own ground rods at the genset. You probably should connect the inverter's ground to the genset via the same power cable that connects the genset power to the 4024.

Start the generator manually, and the inverter will automatically Qualify the genset output, and connect to it after about 30 seconds, if the generator output is within spec. You can adjust the charge current manually, at any time, as well as the charge voltage, time, and a current that will terminate the Absorption stage, etc The Absorption voltage is called Bulk voltage, on these venerable SW Inverter/Chargers, I believe. FWIW. Please let us know how you are doing. Vic

FROZEN · November 2014

Re: Generator for temporary charge

Thanks for the help everyone, makes me feel a little less alone in my endeavor.
The EU3000is has a been powering the loads directly until I have some time this weekend to do a little wiring.

I'll make a dummy plug at the generator side in order to connect to its chassis ground connection and then bond it to my inverter. I'll probably put in some sort of disconnect with a 20A breaker between gen and inverter. I have most of the settings for the inverters charging figured out, just need to double check.

If I had more time to research I probably would have found a more auto start friendly generator, have only found a wireless remote controller so far. Which looks pretty capable, but getting the programmable relays to interface with a remote is above my current knowledge; maybe i can find a way to use a micro controller like Arduino to do some of the control…
So it seems that I don't need to worry about the external trace C60 charge/ load controller having any problems with the incoming power? I don't think there is much to setting out besides the charge values.

Hope this works, hate to run this generator for too long with out benefiting from the ability to charge the battery bank while running AC loads to the cabin.

Thanks again,
Adam

westbranch · November 2014

Re: Generator for temporary charge

you should get a full day of running on a tank at mid load... at least I do.

Vic · November 2014

Re: Generator for temporary charge

FROZEN,

Yes, the C60 and the inverter's charger should share the charge current during the Bulk charge stage. When either is in a voltage-regulating stage, like Absorption, the sharing of current becomes less predictable.

Sometimes, it is good to let the generator do a Bulk in the morning, and try to let the PV CC finish charging, but in "Upper Midwest", there may be little contribution from the PVs on many days.

The Honda EU3000 is my favorite smallish genset. It is frugal on fuel, quiet, and, has a relatively large fuel tank ... what's to dislike !??

Getting any manual-choke genset to auto-start, especially in cold climates, may be a bit of a challenge, or, at least a small project. Good Luck, Vic

techntrek · November 2014

Re: Generator for temporary charge

I have the EU3000is too, and agree it is a great genset. It will last almost a day with an average load at home, I take it on the road for my camper, too. However, it has 120 volt output so if the Trace is expecting 240 on AC1 and AC2, it won't work.

Alaska Man · November 2014

Re: Generator for temporary charge

my experience is that AC2 input is just passed thru to the loads. Chargers charge with 120V not 240 for most of what I've seen or read on RE systems. I know mine does. Don't bother with the Auto Start if your unit is Manual Choke like Vic said. Mine never worked, neither did the remote start in cold weather. Other than that the inverter/generators are the shiz-bit. IMO.

Vic · November 2014

Re: Generator for temporary charge

These venerable Trace and Xantrex inverters are 120 VAC models, at least for NA markets. To get 240 VAC in and out, they are Series Stacked, as Alaska Man noted. Good Luck, Vic

Generator for temporary charge

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