Solar Charge Controller - Setup (help needed)

[arsi315]

I have purchased a product from EPSOLAR company (EPSOLAR Viewstar Series - Solar Charge Controller). I have read the entire manual however I am still not able to set it up according to my system.

VS.gif

I have 48V (1500 W) solar panel attached to the solar charge controller and 48 volt (150 amp 4 batteries in series) attached to the controller. I have read the entire manual and it does guide me how to set up but does not provides me with the data which i have to input into controller according to my system. So can you please kindly tell me details according to how to input the parameters according my system.

Further Details:

Temp showing on controller: 40 C
There is no DC load, The batteries are connected to the UPS (APC 3000W 48V) and load is attached from that UPS which is controlling the voltage.
Eithernet cable is also not working on the controller. Is there any kind of driver I have to install to get it to work on my computer?
Can any one tell me how to control the charging rate from the controller and what is the safe charging rate? and when charging from 220v what is the charging rate? Any help will be appreciated

I am looking forward to your reply.

Here is the blueprint :

solar.jpg

EDIT: SOLAR CONTROLLER SERIES = VS3048N
Link = http://www.epsolarpv.com/c21544/w10135476.asp

[billvon]

So can you please kindly tell me details according to how to input the parameters according my system.

Which parameters do you need? There are a lot of them in a typical controller setup - three charge voltages, a current limit, temp comp value, OVP/OCP/OTP limits etc.

There is no DC load, The batteries are connected to the UPS (APC 3000W 48V) and load is attached from that UPS which is controlling the voltage.

The model you show - vs4024n - is a 12 or 24 volt controller and cannot handle 48 volts. I hope that's just a typo on your diagram.

Eithernet cable is also not working on the controller. Is there any kind of driver I have to install to get it to work on my computer?

Why do you think there is an Ethernet interface? I didn't see one listed on the spec sheet for that model.

Can any one tell me how to control the charging rate from the controller and what is the safe charging rate?

Depends on your batteries. It can vary from C/3 to C/8 depending on the battery manufacturer. Read your battery's spec sheet and set it accordingly. (Since you have a single series string the current limit is the same as the C/X rate.)

and when charging from 220v what is the charging rate?

Depends on your AC charger and your battery. Your solar charge controller will not get involved during AC charging.

[arsi315]

First Thank you very much for replying.

Which parameters do you need? There are a lot of them in a typical controller setup - three charge voltages, a current limit, temp comp value, OVP/OCP/OTP limits etc.

Actually I have no idea which parameters to set because I thought that it will set everything automatically depending on my system. here is the manual:

http://www.epsolarpv.com/c21544/w10135476.asp

The model you show - vs4024n - is a 12 or 24 volt controller and cannot handle 48 volts. I hope that's just a typo on your diagram.

I am really sorry it was a typo .. The model is VS3048N as shown in above link

Why do you think there is an Ethernet interface? I didn't see one listed on the spec sheet for that model.

Again I am really sorry it was a typo .. The model is VS3048N.

Depends on your batteries. It can vary from C/3 to C/8 depending on the battery manufacturer. Read your battery's spec sheet and set it accordingly. (Since you have a single series string the current limit is the same as the C/X rate.)

I am really sorry.. Can you please explain me what is C/3 or C/8 And what happens if I over charge it or undercharge it. Around 1 pm, it was giiving 15+ amps, at 3 pm it was giving 10+ amps, at 5 pm it was giving 3 amps at 6 pm it was giving 1 amp. At night ofcourse its 0 amps but 48 -+ 2 volts.

I have dry batteries (NIRADA EOS Series) (http://en.naradapower.com/products/SLA/agmEos.html) 4 12V batteries in series with 150 AmpH

Depends on your AC charger and your battery. Your solar charge controller will not get involved during AC charging.

Well I was confused because I have heard that if we increase our solar panel we will get more charge or batteries will charge much quicker (Thats what I want) and then if we are using our own electricity (220v) then shouldn't charging rate be unlimited? Because its not taking from solar anymore and is not depending on number of solar panels.


Thank you again for replying

[billvon]

Actually I have no idea which parameters to set because I thought that it will set everything automatically depending on my system.

It can only set a few basic parameters automatically. Others have standard defaults that will work with most systems. In your case the most important screen is "nominal parameter" screen. Make sure to set that to 48 volt, 150 amp. Set PV current to max PV array current (around 35 amps as a guess.) Load current doesn't matter since you're not using the load disconnect feature. Set correct battery type.

For the rest the defaults should work OK. Parameters like equalize/boost/float voltages you can either leave or get from your battery data sheet.

I am really sorry.. Can you please explain me what is C/3 or C/8 And what happens if I over charge it or undercharge it. Around 1 pm, it was giiving 15+ amps, at 3 pm it was giving 10+ amps, at 5 pm it was giving 3 amps at 6 pm it was giving 1 amp. At night ofcourse its 0 amps but 48 -+ 2 volts.

If your battery is 150 amp hours then C=150 amps. C/4=75 amps, C/8=32.5 amps etc. If you overcharge it by giving it too much current, you shorten the life of the battery. Note that this is different from standard overcharge which is just charging too long at too high a voltage.

Well I was confused because I have heard that if we increase our solar panel we will get more charge or batteries will charge much quicker (Thats what I want)

Basically correct.

and then if we are using our own electricity (220v) then shouldn't charging rate be unlimited? Because its not taking from solar anymore and is not depending on number of solar panels.

Your total charge current will be (charger current + solar current.) With AGM batteries you should keep that total below C/4, or 75 amps. Some batteries will accept charging faster; check the battery specs.

BTW I saw no mention of an Ethernet interface in the manual.

[arsi315]

Thank you, Majority of my doubts are cleared by your posts.

Here is the battries I am using:

http://en.naradapower.com/Products/SLA/battdata/pdffiles/MP/6-GFM-150F.pdf

And it is saying the maximum charging capacity is 37.5 Amps So I should set amps in controller to 37.5 amp? And I was reading the manual it says something about temperature coefficient. Do I need to change something about that?

And how do I set the charging rate in my controller for example lets say If i am getting 55 amps around 1 pm the limit i will set (as described above) to 37.5 amp, will it be my charging limit? and what happens when it goes under 37.5 amps lets say around 4 pm? will my controller still provide 37.5 amps or less? And when I am not using solar panel and using the main electricity, there is no controller involved therefore how do I set the charging rate in my UPS (APC 3KW 48V) to 37.5 amps.

In addition, I have increased more panels now, 12 V x 4 panels i.e. 150 Watts / panels

I have also carried out some calculations by searching on google that how long will it take my batteries to be full charged. It says 5 hours ( If you want to have a look at my spreadsheet I can attach it here). and today I did an experiment by cutting my main electricity (220v) and removing load from it. The batteries were charging fine i.e. 2 points out of 5 however after 4 pm, the UPS showed that one point was drained. how is that possible? it makes sense that charging rate will be reduced but how is my battery is discharging without any load?
Is there any fault in my setup (My diagram)?

I am so sorry for bothering you with so many questions but i have spent a lot of money on my system and I want to get everything right?

[Sunking]

And it is saying the maximum charging capacity is 37.5 Amps So I should set amps in controller to 37.5 amp? And I was reading the manual it says something about temperature coefficient. Do I need to change something about that?

No and No. You have not given any panel specs. You say you have 4 panels that total 1500 watts. That is highly unlikely because there is no such thing as 375 watt 24 volt battery panels on the market that I know of.

What make, model, and number of panels do you have?

You cannot set the charge current. It is what it is by design, or the wattage/voltage of the panels and controller type.

[billvon]

And it is saying the maximum charging capacity is 37.5 Amps So I should set amps in controller to 37.5 amp?

Yes.

However, be aware that you are using a PWM controller; they tend to have poor to no current regulation, since they are either connected or not; there's no in between. Either the controller will fail to regulate current or it will pulse the current to try to maintain an average of 37.5 amps when max'ed out. Your batteries may or may not be OK with this.

This is in contrast to an MPPT controller that can maintain an accurate maximum current if programmed to do so.

A better solution is to determine your worst case max current, which in this case would be close to Imppt. Look up your panel's peak power point current (labeled Imppt or something like that on your panel datasheet) and multiply by two (for two strings.) If that's less then 37.5 amps you are OK.

And I was reading the manual it says something about temperature coefficient. Do I need to change something about that?

The battery data sheet does not spec a temperature correction so I'd just go with the AGM default (20-30mV per deg C assuming a 12V battery, or 80-120mV per deg C assuming a 48V battery)

I have also carried out some calculations by searching on google that how long will it take my batteries to be full charged. It says 5 hours ( If you want to have a look at my spreadsheet I can attach it here). and today I did an experiment by cutting my main electricity (220v) and removing load from it. The batteries were charging fine i.e. 2 points out of 5 however after 4 pm, the UPS showed that one point was drained. how is that possible? it makes sense that charging rate will be reduced but how is my battery is discharging without any load?

I don't know what "points" means. What were the voltages and currents when you saw this?

The most accurate way to measure battery state of charge is a gravity reading. You can't do that with AGM cells. The next best way is no-load voltage measurement. Disconnect the battery, wait at least 10 minutes, then take a voltage reading with an ACCURATE voltmeter. State of charge is roughly:

100% 12.8V
75% 12.6V
50% 12.3V
25% 12V
0% 11.8V

Never ever let your battery get to 0% charge. That will destroy it. In fact, if you ever get close to 12 volts with an AGM battery, start to worry; it's not good for it to spend any time at low states of charge.

I am so sorry for bothering you with so many questions but i have spent a lot of money on my system and I want to get everything right?

Hmm. OK. No problem, but keep in mind that often people start with small (=cheap) systems so that when they damage their battery pack it's not too expensive to replace. Batteries work pretty well but they take a lot of care, and are not very tolerant of mistreatment. Keep them charged as often as possible, make sure your system has the power to take them all the way to boost for long enough to fully charge them, and limit max charge currents to below 37 amps.

[Sunking]

Yes.

However, be aware that you are using a PWM controller; they tend to have poor to no current regulation, since they are either connected or not; there's no in between. Either the controller will fail to regulate current or it will pulse the current to try to maintain an average of 37.5 amps when max'ed out. Your batteries may or may not be OK with this.

You cannot set the max current on a contoller, only the cut-off voltages of Bulk, Absorb, Float, & EQ. The panels, charge controller type, and battery SOC dictate what current flows.

[billvon]

You cannot set the max current on a contoller

Both the MX60 and the XW-MPPT 80-600 have maximum current settings. (In the Schneider charger the parameter is called "Max Chg Rate" and is a percentage of the maximum calculated from the AH parameter.) This allows the user to reduce maximum current and prevent battery overcharge. However PWM controllers either do this poorly or not at all.

[Sunking]

Both the MX60 and the XW-MPPT 80-600 have maximum current settings. (In the Schneider charger the parameter is called "Max Chg Rate" and is a percentage of the maximum calculated from the AH parameter.) This allows the user to reduce maximum current and prevent battery overcharge. However PWM controllers either do this poorly or not at all.

What does that have to do with the question? You are talking hybrid grid tied applications where the panels are likely to be way over sized for the batteries.

[arsi315]

Guys thank you very much.. I cant appreciate your efforts enough.

Can you please guide me a little more.

You have almost full knowledge of my system now. I want something like that it charges my batteries all day and we are putting the load at the same time. then same batteries which were charged during the day time are used for entire night. My estimated load is 1000W - 1500W. So how many additional batteries and panels do i need?

NOte: If i dont put any load now, my all 4 batteries are charged in three to four hours from 11 am to 3 pm. But If i am putting load at the same time, Its not charging it almost stays constant or one point is increased (MY UPS shows 5 points (lights) of battery status).. Which only means that I have to increase something now in my system. But I already have spent a lot so please any inexpensive method would be great.

Thank again for replying.

[Sunking]

Watts mean nothing. We need Watt Hours, not Watts. Watt Hour = Watts x Hours. So if your load is 1000 watts and it runs for 10 hours them 1000 watts x 10 hours = 10,000 watt hours or 10 Kwh.