Aims Global LF Series

the_uglydog

Hi, We have some Ames Global LF 10kw inverters. This morning one was alarming for low input voltage of 180 volts. I tested the input breaker and lines and it tested 212 volts, the input terminals test 212 volts, but the unit still says 180 and won't charge the batteries. Any suggestions as to what I should test. We're in The Philippines no dealers here.

BB.

What is the battery bus voltage and the voltage right at the DC input terminals for the AC inverter...

I would double check all the battery to inverter cables and their connections (tight, no corrosion, nothing getting warm/hot, battery voltage (if 48 volt bus, typically somewhere between 42 VDC to 60 VDC). Check battery bank/battery voltages (no low or high battery voltages, no "hot" batteries, if flooded cell check electrolyte levels, etc.).

I don't know of any general source for AC inverter schematics--Most mfgs treat that as company proprietary information and don't let that out.

-Bill

the_uglydog

Hi,
The voltage at the utility input terminals of the inverter are 212VAC, the screen says 108VAC input this morning, last night the voltage at the terminals was 212VAC and 180VAC on the screen, the utility is not charging through the AC charger since the readings are below the 184 VAC utility input required, all connections are tight. The batteries shut down the inverter last night at 47VDC at 10 PM, this morning at 6:55 AM when I checked it again the solar had charged the batteries back to 54.6 VDC and I now have the system back running completely on solar as of 7:10 AM, no problem, the batteries are back to 56VDC from the solar charge. We run three 48 volt 60 amp MPPT chargers for this unit. All battery banks test the same at 56 VDC. The input voltage from the utility still tests 212VAC at the terminals and the screen now reads 155VAC The output voltage was 210 last night just before it shut down, this morning the output voltage is 219. I was just hoping someone had run across this, Ames was only interested in communication when I was buying from them, but all questions since, they have remained unresponsive or responded with "check the troubleshooting guide", if the lazy individual answering had ever read their guide they would have known my questions are never listed in it. Since it will cost more to ship this back to the US to be repaired under warranty than a new one would cost, and all the "experts" I've run across where I am know less than me, I'll look it over myself. Do inverters have capacitors or anything else that stores high current that I should watch out for? Also are there fuses or breakers inside for the utility feed lines on some inverters? I was thinking an input line from the utility input terminals may be loose. Your suggestions are greatly appreciated.  the dog

BB.

TUD,

I am sure you know--But just to confirm... If flooded cell lead acid batteries, they typically "want" 59.0 VDC (aka 14.75 volts for a 12 volt bank) held for 2-6 hours (more hours the deeper the discharge). Float should be around 54.4 volts after the batteries are fully charged (around 13.6 volts max float voltage for a 12 volt bank). And the batteries typically begin to discharge below 51.2 volts (12.8 volts).

If flooded cell batteries, are you monitoring them with a hydrometer of some sort for specific gravity... When you have lots of variable loads and charging sources, just monitoring battery bank voltage is a bit more difficult (with spot checks):

https://www.solar-electric.com/search/?q=hydrometer

You do have several ways to proceed (excluding help from your inverter supplier)... One is see if you can find an AC voltage regulator (basically a multi-tap transformer with electronic control):

https://www.amazon.com/SEVENSTAR-AR-Reglator-Stabilizer-Transformer/dp/B007YK55OA (know nothing about product or vendor--just an example).

Another method is to find a wide input range power factor corrected battery charger:

http://www.xantrex.com/power-products/battery-chargers/truecharge-2-24v.aspx

Xantrex makes 12 and 24 volt wide range AC input (true PF corrected AC input power supplies like the above can take any voltage from 90-265 VAC and 50/60 Hz +/- and charge your battery banks... Depending on the Amp/Voltage rating, I think you should be able to find 48 VAC PFC chargers too.

It is possible that you can find 220 VAC inverter-chargers too with PFC input that might work for you... For example the Contex (Schneider) XW+ with Power Factor Corrected charging (PFC) can take:

https://www.solar-electric.com/lib/wind-sun/DS_ConextXW%2BNA.pdf

L-N: 78 - 140 V (120 V nominal); L-L: 160 - 270 V (240 V nominal)
AC input frequency range (bypass/charge mode) 55 – 65 Hz (default) 52 – 68 Hz (allowable)

Supplies that have PFC front ends are frequently very wide input voltage range (the above TC2 charger 90-265 VAC, the inverter-charger above, 160-270 VAC for 2xx volt input).

I am certainly not knowledgeable enough to make any firm suggestions on what you should get, or what is even available--But the above shows you what is possible today. And hopefully, you can find a local supplier that can help, if not practical to get from USA/North America.

Looking for PFC (Power Factor Corrected) AC input is usually the "magic words" to find a wide input range power supply/charger. Of course, you have to be careful, at 90 VAC, the charger/power supply will take (240 VAC nominal/90 VAC low voltage) ~2.7x more current vs running at a "nominal" 240 VAC (design circuits/breakers appropriately).

It is also possible that many of these devices may not cost effective for (shipping to Philippines, etc.). But they are out there if you can find the right mfg and supplier.

-Bill

the_uglydog

Thanks, we use one of those units on one of our apartment buildings for the deep well. The voltage from the utility fluctuates and sometimes is so low the pump won't work. It fixed the problem, we're hoping to have the solar for that property finished by October. The thing is the voltage input is actually within the tolerance where it goes into the inverter but for some reason the inverter doesn't see it. Yes the cost of shipping here is very high, sometimes higher than what we are buying. All of our US supplies were purchased in the US when we were there and we sent a full container here. Everything here is from China, most is crap, some of it is really good quality, we found a supplier who makes very good equipment and panels and they're super helpful as well and we import things from them. Example their 360 watt panels are less than $100 each, last order, we got 40 panels and the shipping and tax was less than $500. I've found , here, I'm usually better off learning all about any project we have myself. Nothing we hired "professionals" to do has been done correctly, I've had to study, then redo everything. I've gotten pretty good with the solar, our house setup right now is producing almost 100kwh a day  and I hope to have it up to 150 kwh and be able to sustain the house all night by August. Thanks for all your help.  the dog

BB.

TUD,

Wow--That is a good size system (100-150 kWH per day)... One house/business--Or are you making a "micro grid" for a community?

-Bill

the_uglydog

The house, our offices and a couple of guest apartments combine to be about 14000 sqft with two 2 hp well pumps, 2 refrigerators and 18 split a/c units. No one uses central a/c here, the cost to run it 24 hrs a day would be crazy, so we use wall units and splits for the rooms we are using. It get so hot here, 2 days ago it was 99* with 98% humidity, a heat index of about 170* the electric bill is terrible, before we installed any solar it was about $1300 per month only using the a/c in the bedrooms 24hrs, so the payback is real quick, we figure about 3 years.  We also have some apartment bldgs with a deep well that has a 4hp motor next door and a small resort, (not something I like but locally popular) that are not included in that electric, I want to cover those as well. I'm trying to get the main house and offices  which use about 150KWH per day if everything stays on, to 100% solar. I have the priority circuits on an Ames inverter for the lights, and family bedroom a/c units. I have another to power some other bedroom a/c units that are used for visitors and an a/c unit in the family room. We have a 9000 watt grid tie system that we are working on now for the pool pump and extra a/c units for the house connected with water heater times so they only run during the day and I want to set up our 110 system on solar as well. We're planning to add a 12000 watt inverter to power the deep well, the 2 shallow wells for the irrigation and a dryer, setting a priority for them with a priority relay. It's a rather large project for someone who never installed anything more than a solar unit in an rv.
I took the inverter that's giving trouble apart and the input feeds to a breaker inside, with the breaker off, the feed current drops to 0, it's all a very tight fit so I have to figure out how to insulate everything so I can test the terminals inside the unit, I also noticed that as the solar starts to power everything, the reading for the utility input goes back up to about 212VAC and as the solar decreases, so does the utility input..... Strange!  the dog

mike95490

>   ..... I also noticed that as the solar starts to power everything, the reading for the utility input
>   goes back up to about 212VAC and as the solar decreases, so does the utility input....

That's the symptom of a high resistance connection from your house to the transformer on the Grid.

the_uglydog

OK ! The problem started the morning after a typhoon passed by, I thought maybe it was just a coincidence, I should have thought about that, since there is seldom any coincidence.  The wind peak was only 30 mph but there was a lot of rain and here, they don't have much concern for water intrusion into electrical equipment. So the connection at the drop or on the pole could be damaged or wet. I'll check it out. I'm assuming the display on the inverter shows a more accurate reading than my somewhat cheep multi meters, right? This morning it reads 183 VAC for utility input and 229 VAC for inverter output on the display before I turned on any load. I left the inverter hooked up to the solar overnight but switched off the load, the battery was at 50.0VDC when I checked it.  Thanks the dog

the_uglydog

Also, once the load reached what the solar was outputting, the utility input voltage started to drop on the display but stays at 212 on the multimeter. When the batteries are at 55, the utility input goes above 184VAC on the display, but as soon as it drops a little the utility input drops. We have 3 drops from the same transformer hooked to solar, the other 2 seem to be OK, so it may be somewhere around the meter connection that the problem is.  Thanks the dog

the_uglydog

I think you hit the mail square on the head! Yesterday it dried out and the input voltage came back to normal and everything worked as it's supposed to. The different readings on the different multimeters showed all the same. Maybe the one with the wildly different readings has a resistor in it so that it showed what was really going on. I checked by the drop and found someone had changed things from what was there. They tapped into one meter, not the meter that feeds the Ames inverter, to power the construction on one of our apartment buildings and the wires have an outlet spliced into them that's live and lying in standing water. Also they didn't use the washers I gave them to seal the conduit connections and the mains are wet and the insulation on some of the wires looks a bit melted. Nothing like wet electrical connections and equipment. It's too wet around the meters to work on them right now, hopefully it will dry out enough today. Also last night it rained again and the low voltage returned this morning. I'm afraid to go near wet electrical so I'll let you know for sure when the ground dries out enough to go near the power lines and we've found the exact issue.   Thanks the dog

the_uglydog

Hi, I found some loose connections and a loose connection that was wet on the drop to the meter running that inverter. Now the display on that inverter reads exactly what the displays on the other inverters read. I think that may have been the problem.  THANKS for all the input, it is GREATLY appreciated! 
the dog

the_uglydog

Oh well !  Last night the input voltage on the display went down again and the inverter shut off. So this morning I tried changing the input feed from the meter it was hooked to, to a meter that feeds another inverter that's working fine, the input on the display shows low voltage but at the breaker and on the other inverter it is 212. It seems the problem has to be inside the inverter itself. Any suggestions????? 
the dog