SunshineHarvey7

My Thai language ability is pretty limited, and I'm looking for a contractor who can install power polls, run a high voltage line (1km), and install a transformer (30-50kva). I heard how much PEA is asking, and I've also heard that private contractors can do this work (and be approved by PEA) and be very competitive.  So, if you can help me find any contractors at least within an hour or two of Sukhothai, I would really appreciate it. (It'd be great if they can speak English, but I can get someone to translate for me if need be.)

I have a friend in central Thailand who would like to go solar (partly because it might cost as much as 800,000THB to get good grid power to his property), but he is not a technical person, and he is running a children's home with plenty of other responsibilities. So, it seems that he either needs to fork out the money for the high-voltage line (1km from existing line) and transfomer, or else go with the solar plan.

I purchased two cheap (Suoer) 5Kva-48v inverters on Shopee, and I've had frequent problems. Tried to get warranty repair, and the seller didn't do much about it for weeks. And the mfr. hasn't replied to any inquiries directed to their sales email / contact page for over a month as well. So, I'm NOT IMPRESSED and am a bit fearful I would end up recommending a system that will be nothing but headaches for my friend. (Perhaps I can use the equipment I purchased, if it ever works reliably, for an off-grid location I plan to move to soon.) Yesterday I talked to two installers in Chiang Mai... Both offered their sympathies and told me that I'll need to pay quite a bit more for equipment that will have good reliability and warranty service.

So, two questions for those of you in Thailand who have been using solar equipment for a while:

Question 1: Are there any brands that really stand out in your experience as seeming to be good quality, and that have good warranty service in this country?

Question 2: Do you know of anyone in central Thailand (not more than 2 or 3 hours from Sukhothai) that will install and provide warranty service for a solar system?

Question 3: Can you recommend any electrical contractor in that same region who might be able to give me a quote on installing the high-voltage power polls, line, and transformer? (In case my friend opts for this route instead of going solar.)

On 4/6/2021 at 10:59 AM, maxpower said:

 

I posted the YouTube link as a method to find a repair service, I doubt watching the videos will help much.

 

Most provide a Facebook or Line contact for those looking for inverter repair/test service.

Thanks again for sharing the info. I may need that repair guy, if the warranty repair doesn't fix the problem.

On 5/14/2021 at 2:52 PM, 4myr said:

What I have found that fit within my budget and needs are 2 models [ 3/5.x kwh wifi parallel model, the other is 3-5.x kw bluetooth single model], sold by various manufacturers that have them sourced thru Voltronic Power.

 

You will find them as the following brands Victor, Y&H,  Sunmart, Easun, MPP Solar, Sorotec, Anern and Growatt.

I'll be interested in what you find.

My own experience: I tried purchasing a couple Suoer MPS-5KVA-48V inverters. Planning to use them basically for a large-scale "battery backup system" / AVR for a friend. While I've been testing the setup at my house, I've experienced some "Fault 09" errors (which I understand can have a number of causes, mostly by wrong voltages) at times when starting up. The first two or three times I had the error, the error occurred when powering it up the first time after connecting the battery bank, and it resolved itself after several hours of being turned off.

I'm looking around for warranty repair for the inverter that's giving me the most trouble, and finding that the Suoer company is not responding to emails from me or from the (Shoppee) seller I purchased it from. Very disappointing. Needless to say, I can't recommend Suoer. Hope you find a company that has someone here in Thailand who can give you good warranty service.

Okay, another question for the experts ????:

I ran into a friend recently who said, if you hook up more solar panels than your charge controller is rated for, the charge controller will just dump (or it just won't use) the extra power. Is that true?

For example, let's say my charge controller will take 60-110v PV input, and it's rated at 3000 watts (re. charging from PV to batteries). So, I'd take it, if I have 375w panels that have an open voltage rating of around 37.5v (and thus 10 amps), and I hook them up 2 in series to get 75v, then I could connect (almost) 4 sets of panels (3000 watts). So far, I think this is the "normal"/"standard" way of figuring the max number of panels.

However, if my friend is right, I could connect up twice the number of panels, as long as I maintain the voltage of 75v (or whatever's under the max of 110v), and then if it's a cloudy day and the panels are running at 50% of their normal output, I might get full power (since I have twice the "max" number of panels). If it's a sunny day, the extra power just wouldn't get used. Is this correct?

Of course, it does seem to me, a more beneficial way to use those extra panels (and not a lot of extra expense) is to connect them to a second charge controller. Then on a sunny day, my batteries would charge twice as fast (provided I'm not charging too high an amperage for the batteries to take). Does that make sense? Is there any problem with having two charge controllers connected to one bank of batteries, provided that the max output of both charge controllers doesn't exceed the current the batteries are rated for taking?

Thanks for your valuable answers!

18 hours ago, maxpower said:

I have made a suggestion using your post title only and not gone into the detail. Golf cart chargers are available in the voltage and current range you desire.

 

Eg 48V/50A 48V/100A 60V/50A and so on...

Okay, thanks!

32 minutes ago, Crossy said:

I think I would go for parallel off-grid inverters that can supply your peak load.

 

Charge the batteries from solar when it's available or your charger when the sun is hiding.

 

That isolates you from the iffy supply.

 

Size your batteries as appropriate (add more if necessary).

 

Add a change-over switch (manual) so you can use the grid in case the solar goes down.

Yes, I think that's the direction I should go. I've just been learning that for times when solar isn't enough, I'll need a charger that's separate from the inverters. If I did it over again, I don't think there would be any reason to use a "hybrid" inverter for my situation. A standard off-grid inverter (that can work in parallel) should do.

1 hour ago, maxpower said:

LiFePO4 golf cart charger.

What are the specs (output volts, amps, watts)?

1 hour ago, Crossy said:

 

Why not put sensitive equipment on an AVR? Technically much easier than mucking about with chargers etc.

I'd love to. Problem is, with the 1km supply wire from the grid being undersized, an AVR is just going to draw even more amps to make up for the voltage difference, which seems to be asking for trouble. Does that make sense? (I think most people would replace the 1km supply wire, but I sympathize with the owner, who wants to aim for solar instead of shelling out the money for bigger supply wire.)

1 hour ago, SunshineHarvey7 said:

3) "SBU": Solar/Battery/Utility: Grid (utility) power is used as first priority. Solar and battery power is used only when the grid power is not available.

For the record, I described this option incorrectly. When choosing SBU, solar power is used when it is sufficient. If not, then battery power will be used to make up the difference. Utility (grid) power is only used when the battery voltage drops too low.

The inverter also has priority options to select the source of power for charging the battery. With my inverter, I can choose a priority of solar or utility power, simultaneous use of both, or exclusively solar. In this section of the manual, I spotted the reason for my frustrations with this inverter (and probably many similar inverters under other brand names): "If this inverter/charger is working in Battery mode, only solar energy can charge battery. Solar energy will charge battery if it's available and sufficient."

Being that this inverter will take solar panel input in the voltage range of 60-110v, if my friend isn't ready to shell out the money for a bunch of solar panels sand set them up, it'd be tempting to buy a 90v dc switching power supply and feed it into the PV input. (Can't do that once our panels are hooked up, of course.) Then the hybrid inverter would manage the battery charging.

What do you think?

1 hour ago, Crossy said:

 

If you zoom in on the rating plate on the side it's 220V range.

I was about to buy it, and then I realized that I really need a charger that has a wide operating voltage range. This one says 200-230(?) volts. If I'm charging 50v x 60A, that's 3000W, or around 13 amps. At that load, my grid voltage might drop below 170v, maybe around 150v. So I think I better look for a power supply that's not too fussy with input voltage. ????

12 minutes ago, Crossy said:

Would these do the trick?

 

https://www.aliexpress.com/item/4000975323280.html?spm=a2g0s.8937460.0.0.1c102e0ebcaKkK

 

 

It might. One thing that concerns me: I see no mention of an input voltage, and the only amp rating (60A) is in the part of the description that talks about a 27v output (which doesn't make sense since you have 3 options for output voltage to select from when purchasing: 48, 53.5, and 58v). Makes me wonder if the input is 27V(dc?), and the output can be selected at 48, 53.5, or 58 volts. Of course, I need an input of 220v.

I need a 48v battery charger (output up to at least 57v for LiFePO4) that can provide a constant charge to a LiFePO4 battery bank of up around 50 to 60 amps DC. In other words, I want to be able to inputting around 2500-3000 watts into the batteries. I will be drawing off these batteries with an inverter at the same time, so this charger needs to be able to run 24/7 (not shutting off after a preset number of hours/minutes).

For those of you who have shopped around quite a bit in Thailand, do you know of any sources of 48v battery chargers (or DC power supplies that can output up to 57-58v) at 50-60 amps? (I'm aiming at a limit of around 3.55v per LifePO4 cell, or 57 volts for the bank.) I've found some chargers that are rated at 10-12 amps, but some do not state the actual output voltage (I'm thinking some are made for Li-ion batteries and a max of around 54.6v), and I'm hesitant to buy 5-6 of those in hook them up in parallel to get the amperage I'm aiming for.

In case you are curious, at times I will be drawing up to 5000W via a hybrid inverter. My overall usage based on my power bills is less than 30kwh/day. So I'm thinking that an average of 2.5 - 3kw will keep the batteries charged provided I don't draw too heavy a load for too long a period at one time.  (Drawing more than 10-15 amps from the grid power incurs too great a voltage loss on the undersized low-voltage grid power line (which is 1km from light meter & transformer). The owner does not want to replace the undersized wire but build a system with solar power in mind for the future.

You might be wondering why I don't use my hybrid solar inverter to do the job. I wish I could but it appears to me that it's settings are such that the only time it charges the batteries from the grid is when it's NOT using the inverter (and passing grid power on to the output). In other words, it has three "priority" settings for the source of output power:

• 1) "UTI": Use the inverter as a "UPS", passing grid power to the output unless the grid power goes outside an acceptable range (dropping below a selected voltage of 170V or 90V). While grid power is being passed to the output, it also charges the battery bank.
• 2) "SOL": Solar power is the preferred source. If solar power is insufficient, the batteries will be drawn on as well. Grid power is not passed to the output unless solar power is not available (which is true in my case, since we don't have solar panels yet) or the battery level drops to the user-selectable value.
• 3) "SBU": Solar/Battery/Utility: Grid (utility) power is used as first priority. Solar and battery power is used only when the grid power is not available.

My system is designed for the primary purpose of providing a reliable 220-230v, and secondarily to utilize solar power when it is added on. So, none of the above options works for my situation.

Using "UTI" means that I will still pass grid power to the output until it drops to 170v. To me that seems too low. There is another more serious reason not to use this setting: the only reason the grid power drops below 170v is because we are drawing too heavy a load. (There is no one else using this small line from our light meter.) So, if my inverter switches from grid power to battery power when the grid power drops too low, then after the inverter switches from using the grid, the grid power will jump back up to 220+volts. The inverter will sense that all is well with the grid again, and it will switch back to using grid power, which will cause grid voltage to drop again. (And I expect such a rapid cycle of switching between grid and battery power would quickly damage some equipment.)

If I use "SBU", I will be running off the inverter consistently, as long as the batteries can supply the need. When the battery voltage drops to the low limit I've set on the inverter, the inverter will switch to "UTI" mode (passing grid voltage on to the output while charging the batteries) until the batteries are charged up to my preset target voltage. Then it will switch back to the batteries.

My thinking is, if I keep the inverter in "SBU" mode, and add a battery charger to the system to provide a constant feed of at least 50 amps (DC) into the batteries, then my battery bank will not drop too low as long as the heavy loads do not last too long at one time. (If there is some situation where we have a heavy load for an extended time and the batteries are drawn down, then the inverter will switch over to charge the batteries until battery voltage recovers. During this time both the "regular" chargers and the hybrid inverter charger would be drawing from the grid as well as any other loads, so we would likely have a "brown out" until the inverter/batteries can be charged back to an acceptable level. If this situation occurs too much, we will have to consider (1) adding solar panels to supplement grid power and/or (2) increasing the size of the battery bank (currently 4.8kwh) to tide us over during heavy loads.)

Current equipment: Suoer 5KVA 48V Hybrid Inverter; 100AH Sinopoly LiFePO4 x 16 with Daly BMS

In recent months I purchased a 5KVA 48V (Suoer) hybrid inverter. Sometimes when I have had to shut it down to do some maintenance and then re-connected the (LiFePO4) 48V battery to the inverter, I get a 09 Fault/error when I turn the inverter on, and it will not power up. (I now understand that this inverter uses the same board that many other makes of inverters use--confirmed by the fact that the user's manual for this model is virtually identical to a 5KVA model made by Voltronic (Axpert), etc.--so that's one reason I'm hoping that perhaps someone reading this post might have also experienced this problem.)

The first couple times I got the error, I assumed I would have to get it repaired, but each time I've gotten that error, after I let the system set for a while (usually overnight), I try powering it on again, and it works fine. Do you have any experience with a hybrid inverter of this type? Anyone have a suggestion what might be causing this intermittent error and/or how to avoid it? (I wondered whether it could be the large surge that caused a healthy spark when I connected the positive lead, but I doubt it.)

On other forums, some have observed this error when they had fried MosFETS, etc., but since the system has usually worked the next day, I tend to doubt that it's caused by blown part(s).

Appreciate any suggestions.

18 hours ago, maxpower said:

 

The Voltronic boards used in many inverter brands issue fault code 07 - 09 when abnormal voltage is detected in the power switching circuit. This is usually down to component failure.

 

Fortunately the power stages of these very common are easy to test and repair.

 

Try one of the Tube fixers, there are many in LOS.

 

https://www.youtube.com/c/FmlamphunChannel/videos

Are any of these videos in English? (I don't understand much more than very basic Thai.)

And pardon my ignorance--what does LOS mean? ????

23 hours ago, Crossy said:

Have you got mains to the inverter?

Solar panels?

 

Many of the Chinese manufacturers are actually very responsive in English.

I do have the mains connected. No solar (yet). 
 

I sent an email to Souer on Friday. Hope to hear back soon. 
 

I did try the inverter again after it rested for about 36 hours. I must say I was surprised when it fired up without the 09 fault code. It ran for over an hour with no trouble. Then for no obvious reason it shut down again with the same fault. 
 

All of my Lifepo4 batteries read ~3.33 volts. Total ~53.3.
 

While I had the BMS B- & P- shorted, I discovered that I could Bluetooth to the BMS. There I discovered that it thought that cell #2’s voltage was 2.65 volts—which I guess is below the low voltage shutoff. I suspected I must have done a bad cramping job on the connector for that cell. After replacing it, Yippee! the BMS worked! ????

I still can’t understand what’s causing the inverter’s fault code. In the mean time, I’ll be on a week long trip to visit friends. 

Okay, an update to the overall "AVR" plan: I purchased

• a Suoer MPS 5KVA-48V Hybrid Inverter
• 16x100AH Sinoplus LiFePO4 batteries, and
• a Daly 16S 48V 150A "Smart" BMS (R32U GC04, with Bluetooth)

Now I'm full of questions: First, anyone know where to find a user manual for the Daly Smart BMS? (I'm so not used to buying equipment that doesn't ship with a manual and doesn't have a decent one online!!!)

Since I understand the BMS won't "turn on" unless it sees a charger voltage applied that is ~0.5v higher than the batteries, I connected all the BMS wires to the batteries, and then I connected the BMS and battery pack to the inverter. Turned the inverter on, and it would not "turn on" because it didn't "see" the battery pack. I shorted B- to P- for several seconds, and then the inverter turned on. I was pleased UNTIL it appeared to me that it was not charging the batteries. I suspected that the BMS was still not firing up, so I shut down the inverter. After a bite to eat, I went back and tried to fire it up again. Had to short out the BMS B- & P- again to get the inverter to come on.

Now, after coming on for a few seconds, the inverter goes into a fault mode, reading error 09, which the manual says means "bus soft start failed." In another place, the manual states that the possible cause of this error is "Internal components failed," and I will need to "return to repair center."  ????I've emailed the mfr to see if there might be another alternative, but I don't have my hopes up. Anyone have a suggestion?

I must admit, my initial experiences with the Suoer brand of inverters / charge controllers has been a bit sour! ????

On 2/7/2021 at 2:25 PM, Crossy said:

I have found both Sofar and Suoer manuals on the manufacturer's websites.

Hi again, @Crossy, just wondering, where did you find those manuals? Or are you referring to their specification charts? I bought a Suoer ST-H1220 (for another application). Bought it from someone who pieced it together with an inverter all assembled on a board. Nice, but no manuals. ???? I can't find a manual anywhere online. I guess we can just plug-n-play, but it bugs me when I don't know 100% what I'm doing when I step through the settings. ????

58 minutes ago, Crossy said:

I found various resistances for 25mm² Al ranging from 1 to 1.4 ohms per km (cable varies more than somewhat). Is your "1km" actually 1000m?

Yes, perhaps a little more than 1000m, but not much. Satellite measurements come in right around 1000m, and so does my truck odometer. (I'd plan to purchase at least 1100m to be safe if was purchasing the wire.)

1 hour ago, Crossy said:

I know not this "AWG" thing of which you speak, Thailand is a metric country and uses square mm.

I understand. It's just that some wire calculators give AWG recommendations. Fortunately there's a chart here

that helps convert up to the next available size in sq mm.

1 hour ago, Crossy said:

For the record, 25mm² is too small. If you have the smallest meter available (5/15) then the "correct" (5% volt drop) cable is 70mm², if you have a 15/45 meter then look at 300mm²!  Since someone has to pay for the cable and we know their load is small (but could increase of course) we can take a pragmatic approach, hence my 35/50mm² suggestion.

 

That said, 25mm², particularly if you can get it in one piece, will be infinitely better than the wet string they have now.

Really appreciate your approach. Since my friends to plan to expand (add buildings and people), I'm laying out the options for them to string wire that would match closer to the capacity of their meter as well. It would truly be a shame if they put up new wire and then exceeded its capacity.

Thanks again for all your time and answers. What I'm learning will be helpful for this situation as well as some other friends that just purchased property off grid here in Thailand.

36 minutes ago, Crossy said:

25mm² Al is about 1.2 ohm per km, so 2.4 ohms round-trip.

25mm² is about the same as 3AWG wire, then, right? You recommended 35mm or 50mm. Is 50mm about the same as 1/0 AWG? (I'm finding a lot of wire gauge calculators refer to AWG sizes rather than mm² sizes.)

Also, what voltage drop calculator are you using? I found this one that allows me to enter an arbitrary sq mm size of wire, but it comes up with a voltage drop of 20 volts, not 24 volts. No big deal, but I'm just curious if you found a better a calculator than I've found so far.

22 hours ago, Crossy said:

Has anybody looked at putting a bigger cable from the meter (what size is the current cable)? Have any measurements of volt-drop been made at the meter itself? If the voltage is good there a bigger cable could well be the most economical solution.

The cable that terminates the 1000-meter run at the knife breaker at the corner of the property is sized at 25mm². I called PEA, and that is the size they recommend, based on using a 15(45) light meter. The cable has marking on it like this:

However, at the light meter, it is not the same cable (as there were many splices along the 1000-meter run, and the marking on the cable is unintelligible, but another cable that appears to be the same size looks like this: 

Question: Could one brand of aluminum cable that is marked 25 SQ MM (in English) be the same size as another cable that is marked 2 x 6 (followed by Thai annotation)? It's still 1 conductor (not 2), so does that mean a bundle of 6 wires, each of which is 2mm²?

Passing back and forth along the 1km stretch between the light meter and the property, I've observed that the wire does change sizes, and it appears that the majority of the run is with a smaller gauge. Since I don't have a tall ladder, I can't get up and check the wire size, but I agree, @Crossy, probably the best solution is to replace with a consistent 25 sq mm the whole way, with as little splices as possible.

FWIW, the voltage at the pole/meter stays between 225-230V. The supply voltage at our main breaker (if it's open) also reads about the same, but if we close the breaker and have any sort of load on it, the voltage varies from 215V (minimal load) down to 150V or below.

I think we're on to pricing wire and finding an electrician for a quote on replacing it.

1 hour ago, Crossy said:

Has anybody looked at putting a bigger cable from the meter (what size is the current cable)? Have any measurements of volt-drop been made at the meter itself? If the voltage is good there a bigger cable could well be the most economical solution. 

I found a very handy wire gauge calculator here to recommend a size given all the factors. And there's another one here that tells me what voltage drop I could expect if I tell it what size wire I'm using. Based on those calculators, I am realizing the gauge of the feed must be a much smaller gauge than I thought (maybe not bigger than 6mm²). I just arrived at the property so I'll check. Will try to keep you updated. Yes, upgrading the wire may be the most economical solution.

52 minutes ago, Crossy said:

It is important to understand that "hybrid" inverters come in a couple of flavours.

 

The cheaper units are basically a mains battery charger, battery and off-grid inverter. The inverter powers the load using a combination of solar and battery power with the mains charging the battery when solar isn't available and the battery is low. There's usually a bypass to allow the load to operate directly off the mains.

 

The more expensive units add a grid-tie facility to the above which can then push excess solar into the grid and offset the bill.

 

In this instance I think the first option is going to be your solution (I suspect this is what you were suggesting in your original post).

 

EDIT Something like this I think is what you are looking at 

 

https://www.lazada.co.th/products/suoer-inverter-off-grid-hybrid-5kva-48v-4000v-mppt-charge-80a-i1643966486-s4549270369.html

Yes, Crossy, you guessed correctly. I am not aiming to feed anything back into the grid... Just want to charge the batteries when the panels can't keep up with the needs. Due to the severe voltage drop, I don't anticipate ever passing the grid power straight through.

There is no significant voltage drop at the meter, and I appreciate your recommendation to look into bigger wire from the meter. I must do that. I'll be looking for an online calculator to help recommend a gauge. I'm not sure if I'll be able to figure out the existing wire gauge (as I'm sure the existing writing has long since faded).

Regarding manuals for Suoer & Sofar inverters, it didn't seem like either manufacturer had their manual online. I can do some more hunting...

As you may know, Lazada seems to be flooded with what look to me like no-name inverters, with very little specs typically available. I'm looking for a ~5kw hybrid inverter that allows me to limit the charge current from the grid. I'm nervous about just going out an buying the cheapest and hoping it'll work. Do any of you have experience with hybrid inverters? Are there any brands that you would recommend (or warn against)?

So far, I've noticed positive comments regarding inverters from Suoer and Sofar, although the comment may not have been referencing a hybrid inverter.

As the person I'm researching for is not a techie, I expect they will value reputation/reliability.

Hi again. One of my friends is technically on-grid, but his voltage drops from 220v to 180v with a load of only 5 amps! Am I calculating right that that is an 8-ohm impedance on the line coming from the light-meter (1km away!)? (Not sure if I have my terms right here.)

A local electrician says he'll install an Automatic Voltage Regulator (AVR) for 10,000THB. Sounds tantalizing, but I told my friend I don't think this is a good solution. If they try to draw 10 amps, the incoming voltage to the AVR is going to drop to around 140V, and I don't know what the input range is for it (haven't seen any pics or specs on it). Above 10 amps seems even more dubious. Are these doubts well-founded?

FWIW, in the short time these friends have occupied their new property, their electric bills show they have averaged under 15 units / KWH per day (not surprising considering that the lights start to flicker if loads exceed ~8 amps). That says to me, their average load over a 24h time is less than 625 watts. I don't think their peak loads have exceeded 2500 watts, although I'd be surprised if they achieved that (but I'm sure they would like to be able to). In other words, whatever kind of power supply they have, it needs to handle peak demands of 2 to 5kw.

Without supplemental solar power, I can't recommend that they exceed an average load of 1100-1500 watts (5 to 7 amps @ 220V), but we are aiming for a system that will use solar panels to eventually supply much if not all of their needs.
 

At the present time, I'm thinking they should consider starting with a system that is comprised of:

1. A 5kw hybrid inverter, one that can be set to limit incoming AC charging current to 10 amps or under. The brand-name inverters I've looked at so far (Suoer, Sofar) seem to allow such a limit. (Cost: ~17,000ThB?)
2. LiFePO4 batteries set up in 48V strings with each string having a BMS, sufficient to provide at least 9-10KWH of storage. (If I've calculated correctly, that could be achieved by the equivalent of two 48-volt 100AH LifePO4 batteries. (Cost: ~25,000THB?)

As my friends have funds to do so, they could add solar panels to max out the above hybrid inverter's PV input. Before adding the panels, at least the basic setup above should provide them a consistent 220V, rather than experiencing voltage drops to 180V, 150V, etc. And this system should maintain voltage as long as their usage doesn't exceed the inverter's ability to keep the batteries charged.

Does this make sense?

This is a very expensive way to achieve voltage regulation (~42,000), but is there a better way, especially that offers the option of also utilizing solar?