hooking up a generator

ron17571

Help me out here,if i wire up my generator to my battery bank,can i hard wire it in so whenever i use it for something else it well feed to the batterys?any suggestions i looked and didnt find any mention of how people have their generators hooked up.i would be running this from a voltage regulated source at 14.0 volts

niel

Re: hooking up a generator

maybe i'm not understanding you, but it is the same as if the charger were plugged into a utility outlet and wired to the batteries. it may do you well to have a fuse and an on/off switch of proper dc ratings between the charger and battery.

BB.

Re: hooking up a generator

There are AC gensets (alternators) that output 120/240/etc... 60 Hz AC... And there are true DC Gensets that output 24 VDC (typically military) or other voltages.

If you have an AC generator, you can get a good quality 120 VAC (or whatever) battery charger to charge your batteries... And you have the option of running our off-grid loads from the AC Generator directly, or by turning on your off-grid inverter and powering the loads (while the generator both charges the batteries and supplies current to run the inverter)...

And--there are Inverters that have internal battery chargers... You connect the DC input of the inverter to a battery. And your load to the inverter's output.

You then connect the AC Generator to the Inverter's GEN or AC input.

Now, when the generator is off-the battery+inverter supply power.

When the AC Genset is running, the transfer switch inside the inverter connects the load directly to the genset, and also charges the battery bank at the same time.

Some Inverter/Chargers are smart enough to share the generator output between the AC load and battery charging... (limits the total AC input to prevent popping the AC Generator's overload breaker).

The inverter/charger can be very nice this way... You can use a smaller (fuel efficient) Genset to both run your AC loads and charge your battery bank because the inverter/charger limits the charging current if there is a heavy AC load at the time "maxing" the Genset's capacity.

-Bill

icarus

Re: hooking up a generator

If the question is as simple as it seems. A simple manual or automatic transfer switch will work fine.http://search.store.yahoo.net/cgi-bin/nsearch?catalog=wind-sun&query=transfer%20switch&searchsubmit=Go&vwcatalog=wind-sun&.autodone=http://store.solar-electric.com/linecard.html

Installed properly will work fine.

There are also double throw manual switches available,

Tony

Cariboocoot

Re: hooking up a generator

Note: some generators, such as the Honda inverter series 1000/200, have both 120 VAC and 12 VDC outputs. You can not use both AC out and DC out at the same time.

dwh

Re: hooking up a generator

Cariboocoot wrote: »

Note: some generators, such as the Honda inverter series 1000/200, have both 120 VAC and 12 VDC outputs. You can not use both AC out and DC out at the same time.

I think this may be incorrect.

I don't have a Honda generator, but from what I've read they are built with separate windings for AC and DC and you *can* use both at the same time.

I've just looked through the manual for the eu2000i and I didn't see anything in there that prohibits using both at once.

http://www.avchicago.com/AVC_PDF/HondaEU2000iManual.pdf

I will note that the 12v output of these generators is specifically to be used for *battery charging only* and is NOT to be used to supply power to 12v devices.

Cariboocoot

Re: hooking up a generator

Quoting my Honda manual, page 16:

"NOTE:
The generator cannot be used for both AC and DC simultaneously."

There aren't separate AC/DC windings on these inverter units; they generate DC and 'invert' to produce AC. Drawing on the DC will seriously deplete the power available to supply AC.

If they've changed this since I bought mine, I'd like to know.

dwh

Re: hooking up a generator

Cariboocoot wrote: »

Quoting my Honda manual, page 16:

"NOTE:
The generator cannot be used for both AC and DC simultaneously."

There aren't separate AC/DC windings on these inverter units; they generate DC and 'invert' to produce AC. Drawing on the DC will seriously deplete the power available to supply AC.

If they've changed this since I bought mine, I'd like to know.

Hrmm. Page 16 of the manual I linked to above does not say that. Looking at the EU2000I Owner's Manual(s) (there are 3 listed) from the Honda web site:

http://www.hondapowerequipment.com/products/manuals/default.aspx

None of them say that. Searching for the word "cannot" gave 3 hits in each document. Searching for the words, "can not" gave no hits.

Is your generator a different model? I went through the EU2000I manuals, but don't really have any desire to search the manuals for every Honda model.


As to the windings, the schematic shows "main winding", "sub winding", "dc winding" and "exciter winding". The schematic shows the output from the "dc winding" going to a "rectifier" and then to the "dc outlet receptacle".

Are those not separate windings? Or am I reading the schematic wrong? (I'm an electrician, not an electronicist.)

icarus

Re: hooking up a generator

Figure out which model you have and RTFM.

I think this is getting away from the OP's question. (Or not depending on what he was really asking!)

T

Cariboocoot

Re: hooking up a generator

I must live in an alternate reality. Does Canada count as that?
The on-line manual is significantly different from the printed version I have. Admittedly, I've had this beast a very, very long time but .... Could they have changed that much over the years?

It does say: "Specifications subject to change without notice."

I checked the 1000 manual & the 2000 manual - neither on-line version match my printed editions.

They do appear to have separate windings now, but the principal is the same: the engine can only put out so much HP, and if it's going to DC it won't be available for AC and vice-versa. My guess is that the electronics wouldn't know, so the motor would be taxed and the output available to each reduced as if there weren't enough HP. Sort of like running an inverter off low batteries; current goes up, output potential goes down.

dwh

Re: hooking up a generator

Cariboocoot wrote: »

They do appear to have separate windings now, but the principal is the same: the engine can only put out so much HP, and if it's going to DC it won't be available for AC and vice-versa. My guess is that the electronics wouldn't know, so the motor would be taxed and the output available to each reduced as if there weren't enough HP. Sort of like running an inverter off low batteries; current goes up, output potential goes down.

Makes sense.

Also the manual says to turn off Eco Mode when using the DC to charge a battery, so even if it's possible to use the AC at the same time, you would probably be running the gen flat out to do it.

I never claimed that it was a good idea to do it - just that you can.


(As for being off-topic...well Bill answered the OP pretty well in his post, so this is all just gravy anyway.)

ron17571

Re: hooking up a generator

I guess i should have been more clear.im thinking of powering up a 63 amp car alternator,hooked up to a battery and an inverter to run a washing machine,i figure i well have power to spare and thought i would hook up to my battery bank and use some of the excess power to help top off the battery bank.

Cariboocoot

Re: hooking up a generator

You mean run an alternator off a gas engine to provide 12 VDC charging for batteries?
That would work. Maybe not the most fuel-efficient design possible, as it has to turn the DC in AC for all loads whereas a generator would produce AC 'directly', as it were. But if it's what you've got already to work with, it's cheaper than a generator, right?

One note; washing machine = big load. They generally have 1/3 HP AC induction motors to run the agitator, and that will use up to 1000 Watts running (plus more on start-up). Good idea to check the machine first with a Kill-A-Watt to get real-world figures on what it will use.

A 63 Amp alternator is theoretically capable of about 746 Watts - one electrical HP. Its actual capacity will be less, due to efficiency losses (and you don't want to run it at peak output all the time - it would shorten the life). But it will require more than 1 HP to run it.

While the washer is running it will probably draw more than the alternator is capable of supplying, so be sure you have enough battery bank to make up the difference.

mike95490

Re: hooking up a generator

That inductive load will also have a lousy power factor, and you may need a larger inverter to keep that happy.

RCinFLA

Re: hooking up a generator

The 12vdc outputs are usually only about 10 amps max so against a 1-3 kW generator it is insignificant.

My Yamaha has separate windings for the 12v output as well as second separate low voltage winding for running its inverter circuitry.

It allows use of A.C. output and D.C. 12v at the same time.

Cariboocoot

Re: hooking up a generator

"Your Actual Generator May Vary."

From the side of my Honda 1000 (the 2000 has the same warning on it):

(You may not be able to read it. The WARNING on the right says "do not use AC and DC at the same time".)

mshen11

Re: hooking up a generator

i have a yamaha ef2800...

is using the DC battery charger on the generator more efficient than plugging in an off the shelf AC battery charger?

mike95490

Re: hooking up a generator

Likely not. It's possibly OK for the "bulk" part of the charge cycle, but it's not regulated at all, and won't finish/top off, the batteries properly.

Cariboocoot

Re: hooking up a generator

mshen11 wrote: »

i have a yamaha ef2800...

is using the DC battery charger on the generator more efficient than plugging in an off the shelf AC battery charger?

Compare the output current rating of the gen's DC to that of the battery charger that can be run from the gen's AC. Chances are there's a big difference. The Honda 1000's DC output is 6.5 A, but its AC can run a 30 A charger. The type of charger makes a difference too: the gen's output is for "automotive type" batteries only; it won't supply the 3-stage charging desired by a deep cycle type. But the AC can run such a charger.

dwh

Re: hooking up a generator

ron17571 wrote: »

I guess i should have been more clear.im thinking of powering up a 63 amp car alternator,hooked up to a battery and an inverter to run a washing machine,i figure i well have power to spare and thought i would hook up to my battery bank and use some of the excess power to help top off the battery bank.

Yes, you can do that - if you have excess power. That alternator will put out a max of somewhere around 800w.

The issues are:

A) auto alternators usually put out less voltage at lower RPM (and frequently they put out nothing at all at engine idle speeds), so you'll need to rig it to run the alternator at the right RPM, and

auto voltage regulators usually put out less voltage than a deep cycle battery setup will likely need.

So, you can divert the excess into the batteries, but only up to a point. If your batteries need 15 volts to get them up to full, and your alternator rig only puts out 14, then you'll never quite get the batteries full.

benthere

Re: hooking up a generator

I just wanted to point out that our washing machine (LG2301) is using about .12 KWH/load. Not a huge demand in my mind. We run a ventilation fan in the evenings that uses more than that

Obviously this may differ greatly between machines. My money goes to efficient appliances before fuel for the generator.

solorone

Re: hooking up a generator

Cariboocoot wrote: »

You mean run an alternator off a gas engine to provide 12 VDC charging for batteries?
That would work. Maybe not the most fuel-efficient design possible, as it has to turn the DC in AC for all loads whereas a generator would produce AC 'directly', as it were. But if it's what you've got already to work with, it's cheaper than a generator, right?

One note; washing machine = big load. They generally have 1/3 HP AC induction motors to run the agitator, and that will use up to 1000 Watts running (plus more on start-up). Good idea to check the machine first with a Kill-A-Watt to get real-world figures on what it will use.

A 63 Amp alternator is theoretically capable of about 746 Watts - one electrical HP. Its actual capacity will be less, due to efficiency losses (and you don't want to run it at peak output all the time - it would shorten the life). But it will require more than 1 HP to run it.

While the washer is running it will probably draw more than the alternator is capable of supplying, so be sure you have enough battery bank to make up the difference.

Well i am new here, just found this place a few minutes ago. If you are charging batteries, I do not see why this will not work. I used the same system 26 years ago to power my house until we got the panels. I strapped 3 Ford alternators to a small cable laying machine powered by an 18 HP motor, I had a potential of 170 amps, but regulated the input to get 50% output. I loved it, $13 a month for fuel, but keeping the machine working could be a pain. I could see this as a supplemental system today. The one ?? I would have would be how does today's alternators work. Way back then GM had a built in regulator, Ford did not, and they were cheap of the shelf. If anyone is interested, I can speak to the viability of using a system like this. Send a PM