Gen / Xantrex Charging Problem

[dohenyboy]

I have a charging problem that I just cannot figure out. Everything has been working fine for two years and something broke.

I am on a mooring, so except for a wind generator that keeps the batteries topped off, and running the engine, my main source for electrical power is a Northern Lights 6kW genset. The genset is wired to produce 120V AC.
I have two chargers on board, an older (2003) Xantrex inverter charger (2500 W inverter, 140 amp charger, for the house bank ), 7 Lifeline AGM batteries with 105 amp hours each) and a Xantrex True Charge 20 in the bow for the anchor windlass batteries.
The big charger is one of those with transfer switching. While AC is input, up to 28 amps is used for charging. However, any AC demands from the ship take precedence and reduce the current available for charging. I have it set up for 1 AC input and 1 AC output. (there are two AVAILALBE inputs and two AVAILABLE outputs but I don't need that complicated of a set up) If there is no AC input on the unit, it acts as a pure inverter, supplying 120v AC from the battery bank.

The genset AC goes through a ship/shore switch then, the neutral wire goes to a small AC neutral bus, and the hot wire goes to the two breakers-one for the big charger and one for the bow charger.

The bow charger works great.

The big charger does not. When there is no AC input, it inverts just fine. It will not charge, and when there is AC input, no AC comes out the AC output (no "pass through").

I took out the charger and had Xantrex look at it. It tested good.
Then I bench tested it at home, using house current for the input, a vacuum cleaner plugged to the output, and a marine battery hooked up to the DC outputs. The charger did work perfectly. It charged, and passed through the AC to the vacuum cleaner.

So, there must be something wrong with the boat. It has to be either (a) my house batteries, (b) bad AC from the generator, or (c) something wrong on the AC panel or further downstream.

I took the big charger, the marine battery and the vaccum cleaner to the boat. I connected the charger input to the ship shore switch, and connected the same marine battery to the DC outputs. I did not connect the AC output. In other words, the same as at home except for the AC input.
It did not work. No charging and no pass through of AC (I tested with a digital multimeter) I was getting 120v AC from the generator. I could hear the transfer switch inside the charger click and the charge light came on. But voltage at the battery was unchanged. I took the ship shore switch out of the circuit, wiring the generator directly to the charger, no difference. I then connected the generator line to an outlet box I made up, and the vaccum worked.
The Xantrex repair people are flabbergasted.
Anyone out there have an idea?
A new Xantrex is over $1000. I may get one of the Iotas but I would rather not have to spend any money

[btrayfors]

Xantrex transfer switches are a known weak point; they often fail. That may be the problem, i.e., yours is intermittent (works at home, but not on the boat). I just pulled one out of a 46-footer that exhibited that problem (2500W inverter/charger). Owner decided to replace the unit with a Victron MultiPlus inverter/charger, which is working well.

Another possibility: some chargers are very sensitive to FREQUENCY...if you don't have very near 60 cycles coming from the genset, or if the voltage and frequency are jumping around due to a faulty voltage regulator circuit, the Xantrex may be rejecting its input.

The Iota option is probably a good one. The price-point might be to use two 75 Amp DLS-75/IQ4 units which can work together....150A. They run about $300 each at Arizona Wind Sun & other outlets. Even less expensive would be two 55A units (110A total) which could be had for about the price of one 75A unit. Be sure you get the IQ-4 smart charge adapter if you decide to go this route.

Good luck,

Bill

[donradcliffe]

Here are some ideas from an ealier discussion on another board

SSCA Discussion Board • View topic - Heart Freedom 20 Inverter Battery Charger Inop

[Chief Engineer]

Do you have GFCIs?

Or did you try to run the vacuum cleaner like you had it set up at home?

[dohenyboy]

first, thanks for the ideas. Maybe the generator is not putting out the best power like it used to, and that is why. I think I will just get the iotas

how I did the vaccum-on the output lead, I attached an outlet and plugged the vacuum on it. I left the outlet on when I reinstllaed the charger/inverter
there is no GFI on the circuit. I just jumped the AC from the generator to the plug for the vacuum and it worked fine

[svquest2]

I have a Trace 2500 watt true sine wave inverter (later bought by Xantrex) and my inverter will cut out AC passthrough if the voltage is outside of the nominal by +/- 10%. In my unit you can change the setting to accommodate greater extremes and it includes meters to tell you what the input really is. I would look to your generator first and remember the better units have that protection built it to prevent you from frying sensitive electronics. Don't junk a good inverter/charger if it's doing its job. Perhaps a quick trip to the dock to plug in some good shore power would help.

Here is a picture of my unit

Good Luck

Joe S

[JayH]

I have two stacked Trace/Xantrex 2500W Inverter/Chargers (PS2524) and a Northern Lights 12kW. They work fine together. The inverters can be choosy about the power source, but the OP said the charge light comes on, which means the source AC is being accepted.

What if the inverter and the vacuum are plugged into the generator at the same time? I wonder if the vacuum would work.

My thought process is this: My inverters will trip a shoreside GFCI every time. It has something to do with a noise filter inside the charger. I wonder if the generator might have something similar. If so, I would expect the vacuum to stop working.

[dohenyboy]

that's just the thing. The charge light comes on, but there is no DC output. Not even a milliamp

[captden]

I'm having a strange problem with my heart 3000 inverter/charger when charging batteries from my genset. When I'm connected to shore power the charging current will be as high as 90 amps being put into the bank and the charging voltage will quickly rise up to 14.50 volts and all is normal. When I run the genset which is 5.5 kw the charging voltage does rise but very slowly and only up to 13.9 and the charging current stays around 30 amps. Now my shore power is only a 30 amp service and I have run this setup on just a 20amp source. As I said the genset is 5.5kw and I believe that adds up to about a 50 amp service, and I have no problems running any of my 120 volt systems including a pc so I know it cannot be a cycle problem. It doesn't seem to be a lack of current output from the genset as it acts the same if I run any other loads or just trying to charge batteries. I have a link 2000 that monitors the system and for example yesterday when I charged the house bank that consist of 4 trojan 105 that were only discharged down to 60 amphours used and the battery voltage was still 12.5 before charging and it took over two hours to bring the bank up to 13.80 volts and still around 20 amp hr used. The power share on the charger is set the same for both shore power and genset power. Any ideas?
Captden

[CharlieJ]

Older inverter/chargers, especially Freedom modified sine wave units, have a notoriously bad power factor. To compensate for this, Freedom (now Xantrex) issued a technical note several years ago saying, in essence, regardless of the calculation, don't attempt to power the charging function of a Freedom 2.0 kW or larger with less than an 8 kW genset.

That being said, you can limit the amount of incoming AC power that is used for charging but you pay a price in longer run times.

Hope this helps.
Charlie

[captden]

Thanks for the info Charlie, very interesting, I seem to be missing something here, how does the inverter know the difference between shore power which is only a 30 amp service or around 3kw and a 5.5kw genset which is around 50 amp service, I would think the lesser current on the shore power side would be the problem
Captden

[CharlieJ]

Here is the link to the original TechNote:

http://www.xantrex.com/web/id/735/DocServe.aspx

Charlie

[captden]

Great info thanks Charlie, I'll have to see what it will do adding a resistive load when charging
Captden

[GordMay]

Originally Posted by captden

Great info thanks Charlie, I'll have to see what it will do adding a resistive load when charging
Captden

Power Factor Correction is NOT a subject for amateur “tinkering” - it’s a little more complicated than adding CAPACITORS (not Resistors) to the circuit.

There are two general causes of poor power factor: lagging* reactive loads (inductive Xl) and electronic power supplies.
Poor power factor caused by inductive loads, such as motors, are corrected by adding a capacitor (leading reactance Xc) in parallel to the load.

* Memory aid: “CIVIL” – in a Capacitor the I (current) leads Voltage, Voltage leads I (current) in an inductor L.

Electronic power supplies, (for example, inverters, computer power supplies, & other non-linear loads) on the other hand, cannot be corrected by merely adding capacitors in parallel. In order to improve their Power Factor & Harmonic Disortion (THD), these devices have to be designed with active* power factor correction.

See the sections on Inverters & Harmonics at the end of this tutorial:
➥ POWER AND POWER FACTOR IN AN AC CIRCUIT

Some good basic tutorials on Power Factor:

➥ Lessons In Electric Circuits -- Volume II (AC) - Chapter 11

➥ http://www.theiet.org/publishing/wir...r.cfm?type=pdf

Power Factor and the Modified Sine Wave:
➥ Power Factor - facts vs fiction

[captden]

Originally Posted by CharlieJ

Older inverter/chargers, especially Freedom modified sine wave units, have a notoriously bad power factor. To compensate for this, Freedom (now Xantrex) issued a technical note several years ago saying, in essence, regardless of the calculation, don't attempt to power the charging function of a Freedom 2.0 kW or larger with less than an 8 kW genset.

That being said, you can limit the amount of incoming AC power that is used for charging but you pay a price in longer run times.

Hope this helps.
Charlie

Thanks again Charlie, guess I should of researched a little harder before I bought and installed this setup, so what should be my next move? We plan on heading out next year and will be on the hook most of the time. I'll also be doubling my house bank by adding 4 more t-105s and with the setup I have now I'll be spending way to much time charging. I just installed a wind generator on the boat to help but I know it still will take a long time to maintain good charging. Are the newer charger/inverter the same as the older ones? Or should I start thinking about adding a high output alternator to the genset? Are there chargers out there that will put out the current we are talking (100 amps) that will run on a 5.5kw genset?

Not really interested in putting solar panels if I can help it.

Captden