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Off grid living with solar DC and AC

rohitgandhii — Fri, 25 Jun 2021 03:00:00 GMT

I started building a hybrid solution 7 years ago. I am a journalist and an experimenter. I have 8.5KW AC. I have a 4KW invertor 48VDC that is analog and an invertor that is 12VDC.

I have 26 panels of 36V and 4 panels of 12 Volts. I have 5 lead acid batteries of 150 AH.

I run a submersible pump of 3KW DC with 10 panels.

My question is that is there a way to bring all the lower to one location when they are not being used for water and then distribute the DC supply better. I run out of power at about midnight

BK precision 8602 DC electronic load for Solar panel IV curve simulation

sreeharshab — Thu, 16 Apr 2020 12:42:11 GMT

Does BK precision 8602 DC electronic load has inbuilt option for IV curve simulation when a solar panel is connected. If there is no such an option, can someone help me towards relevant material/document as a guidance for using the 8602 model for collecting IV curves. I found a review discussion on element14 on using the BK 8602 to plot IV curve using html commands. However, the details are missing to understand the procedure.

RE: BK precision 8602 DC electronic load for Solar panel IV curve simulation

shabaz — Sat, 18 Apr 2020 00:32:45 GMT

Hi Sree,

I think it's the one you're referring to in the original question, see here:

Programmable DC Electronic Loads with the BK8600 - Review

There's a zip file attached there.

RE: BK precision 8602 DC electronic load for Solar panel IV curve simulation

sreeharshab — Fri, 17 Apr 2020 20:48:47 GMT

Thank you very much shabaz. I will refer the programming guide of Bk8602 for coding part. You were talking about a review in your response . Can you provide a link of your review ?

RE: BK precision 8602 DC electronic load for Solar panel IV curve simulation

shabaz — Thu, 16 Apr 2020 13:53:11 GMT

Hi Sree,

It is not built-in, it needs programming, but it's staightforward. You can do it easily by sending SCPI commands to set the BK8602BK8602 into 'constant voltage' mode, set a voltage value, and then retrieve the power or current value. Plot it, and then increment the voltage value. You'll end up with your desired curve.

I don't have the entire code I used (I lost it) but I re-wrote the SCPI handling part a while back, it is attached to the review. It implements it in Python. Use the BK8602BK8602 programming guide to see the command to set to constant voltage mode and so on. You might have to edit the code but it's a good start. If you don't wish to write code, something like LabView may be easier I don't know. You still have to 'program' but it will be more graphical.

Use your code to generate (say) a CSV file and then you can plot it, or there are many libraries you can use to directly plot. If you wish to use a library to plot it, it depends on the language. Generally Python and 'matplotlib' is probably easiest for a newcomer, otherwise select the language of your choice. If you want to see a general example of how to plot, let me know I can point you in the right direction.

EDIT: For LabVIEW, if you're a beginner, see some of Jan Cumps blog posts such as this one: PiFace, Raspberry, LabVIEW and LEDs it's probably the most up-to-date information for people looking to use LabVIEW.

RE: Using dual output power supply in parallel

rscasny — Thu, 09 Apr 2020 12:14:47 GMT

To all,

I was forwarded the user manual, just in case you didn't have it:

72-10495 72-10500 72-10505.pdf

Also, the tech support guy told me:

Farnell 2251947 can be used in parallel or series modes.

As this power supply with dual channel, so 2 channels in parallel can output Max.10A.

2 pcs 2251947 in parallel can output Max. 20A in all.

Operation of parallel and series in page 11&12 of the user manual.

RE: Using dual output power supply in parallel

colporteur — Thu, 09 Apr 2020 00:04:35 GMT

Great to hear of your success and that no magic smoke was released in the process.

RE: Using dual output power supply in parallel

xueyin.agerris — Wed, 08 Apr 2020 23:26:03 GMT

You guys are right. The model only has one channel on the right hand side, and only two in total. There is definitely a lot of mismatching information happening here.

Yep, I did try it in parallel operation. I hooked up my load to how the picture indicates (and not the text), i.e. across the right output channel only. I didn't need to hook anything up to the left channel. I only needed to set the voltage/current limits on one channel, and the settings were mirrored in the left output indicators. I measured the output current and it was the full current I was expecting.

When I turn on the output however, the screens on each output unit indicate half the current draw. So if I was drawing 12A in total, each output screen would show 6A. The current actually being outputted is still 12A though.

In short, I had no problems hooking the power supply up to how the pictures (not the text) indicate for parallel operation. I have not yet tried series operation.

RE: Using dual output power supply in parallel

michaelkellett — Wed, 08 Apr 2020 08:41:22 GMT

And the picture with the connections is not the same device as shown in the data sheet or on Farnell's website. (The one in the extra manual has four terminals on the right hand side rather than three.)

It's such a shame that Tenma haven't got the documentation sorted - it seems that the actual hardware has all the right features (internal relay for series or //) - which is very good for its price class.

@ Xue Yin Zhang have you tried it yet - do the active meters indicate the full current and voltage ?

RE: Using dual output power supply in parallel

Jan Cumps — Wed, 08 Apr 2020 05:32:06 GMT

Text vs drawing in the manual aren't aligned:

RE: Using dual output power supply in parallel

colporteur — Wed, 08 Apr 2020 01:01:28 GMT

Thanks for the share. It closes the loop for me.

The manual picture provided doesn't look like the unit I used in my parallel & serial pictorial. It was in your best interest to find the documentation. Sounds like you got everything you need to continue. If your plan is to draw some amperage don't skimp on cable gauge. Good luck.

RE: Using dual output power supply in parallel

xueyin.agerris — Tue, 07 Apr 2020 23:26:19 GMT

Thank you for all responses so far! To Michael/Sean: yes I was hesitant to hook up my load because the provided documentation doesn't indicate how this particular model is meant to be used in series/parallel operation.

I got in contact with technical support at Element 14 and they sent me these photos in an email:

It's a shame this documentation is so difficult to find. I tried searching the heading in the top right corner, but unfortunately, I still don't know where these pages came from.

Regardless, it is here if others so seek out this information!

RE: Using dual output power supply in parallel

colporteur — Tue, 07 Apr 2020 17:48:47 GMT

Your concern has some merit. The physical configuration wouldn't be my first choice. That being said, it is not a fry the circuit configuration for a dual power supply.

As I indicated in my post the configurations may be supported programmatic through the powers supply menu. The description by xueyin.agerris "I would have to connect +ve to +ve and -ve to -ve across the two outputs?" caused me concern. I felt a visual of what would be a correct configuration was better than a verbal.

To be honest I'm not even sure if the pictorial is the correct model. The link provided in postings didn't source for me. So I used a Google search that returned a picture.

RE: Using dual output power supply in parallel

michaelkellett — Tue, 07 Apr 2020 08:04:26 GMT

I'm very concerned that this wiring advice is not correct for this power supply !

It is how you would connect two isolated supplies but if this model was intended to work like that it might not need the external connections.

It has two buttons and indicator lights for // or serial operation - on some supplies the metering is correctly connected for these modes, on others you have to do your own addition of current or voltages.

On some supplies the special modes cause the supplies to track voltages, on other not.

The manual does not mention these modes.

Can you post the actual link so we can see where the information came from.

RE: Using dual output power supply in parallel

colporteur — Tue, 07 Apr 2020 00:32:14 GMT

If I recall my basic electronics correctly here is a physical hookup for a parallel or serial configuration for dual power supplies. The supplies my provide this capability using a programmable configuration and not require physical jumpers.

Another consideration is to ensure none of the power supplies have limiting that will result in one supply trying to carry the load. I recall working on a unit that had three supplies feeding a combiner. When one supply got weak the others would still try and carry the load. At some point the other supplies limits would trip because the two were trying to do the work of three.

I did a search on the power supply reference you provided. This is what was returned for a link.

RE: Using dual output power supply in parallel

rscasny — Mon, 06 Apr 2020 18:53:29 GMT

I'll agree that the Tenma product manuals aren't as descriptive perhaps they could be. Roadtesting them is a good possibility. I will talk to the product manager to try to get some help.

Randall

Using dual output power supply in parallel

xueyin.agerris — Fri, 03 Apr 2020 06:25:15 GMT

I have a Tenma 72-1049572-10495 power supply with two outputs. Each output can deliver 5A current, but I want to use both in parallel to deliver up to 10A.

How can I hook up my load to the two outputs to work in parallel?

What settings do I have to configure to be in parallel operation?

RE: Using dual output power supply in parallel

michaelkellett — Mon, 06 Apr 2020 08:39:16 GMT

If rscasny is watching perhaps he could consider offering one of these PSU s for Road test and we might get some definitive answers.

Or, perhaps, he could have a word with the appropriate colleague about getting a more comprehensive manual put together.

RE: Using dual output power supply in parallel

baldengineer — Mon, 06 Apr 2020 02:18:31 GMT

xueyin.agerris wrote:
For parallel operation, would you say I would have to connect +ve to +ve and -ve to -ve across the two outputs?

Well, this question is usually answered by the manual. In other supplies that have a serial/parallel button, you typically use the positive from CH1 and the negative from CH2.

A clue would be if you hear relays clicking when you enable/disable those modes. Another way to tell would be to measure the voltage at the terminals to see what pairs are active.

RE: Using dual output power supply in parallel

xueyin.agerris — Mon, 06 Apr 2020 00:28:42 GMT

Thanks for your reply Michael!

Perhaps I will have to do some experimenting. For parallel operation, would you say I would have to connect +ve to +ve and -ve to -ve across the two outputs?

RE: Using dual output power supply in parallel

michaelkellett — Fri, 03 Apr 2020 08:43:39 GMT

You may have to do some experimenting !

The manual (which I found on the CPC website) makes no reference to it but there is an indication on the front panel that series or parallel operation is possible.

Assuming the second function of the SER/IDEP and PARA/INDEP buttons is like the BEEP button:

remove all connections

Press SER/INDEP untill the SER led ligts - I guess it will now be in series mode but I don't know if you need to make the serial connection yourself.

Connect a meter across the right hand set of terminals and adjust the voltage and see how it changes, do the same for the other set of terminals. Now you know if it does the connection internally and what the meters read.

On some instruments the two supplies will track and one meter will read the full voltage, on others you need to do your own addition.

You could also ask Farnell/Element 14 why they can't make the effort to supply decent operating instructions with their own brand stuff !!

Good luck.

RE: Ic L6563H BLOWN ALL THE TIME

michaelkellett — Fri, 14 Feb 2020 15:25:52 GMT

There are many possible faults that will not show up with simply testing on board with a multi meter. (For example shorted turn or failed insulation in a transformer or inductor).

If there is a fault in a later section of the supply that could still make the L6563H fail.

And it could have been a duff chip.

The L6563h is pretty cheap - might be worth another go with one from Mouser or Farnell.

RE: Ic L6563H BLOWN ALL THE TIME

manzoor — Fri, 14 Feb 2020 14:41:27 GMT

Thanks for reply

I check all the component and there is not any component short. Also the power supply is with out load tested

Ic L6563H BLOWN ALL THE TIME

manzoor — Thu, 13 Feb 2020 19:29:26 GMT

Hi I have a fujistu desktop power supply dead . So I open testing all component in primary section and found fuse blown 250v 8amp. Mosfet 23nm60n blown . Ic L6563h blown other all component are tested ok so I replaced all with new one. Which I bought from online aliexpress. But the problem is same mosfet and ic again blown . There smd resistor smd capacitor all value are tested ok rectifier and all component. Then I again replace and the problem is same. Does any one faced problem like this please share I feel ic which I bought from aliexpress is not genuine which caused blown

RE: Ic L6563H BLOWN ALL THE TIME

dougw — Thu, 13 Feb 2020 19:40:47 GMT

Excessive load on the power supply can cause power supply components to die.

The root problem may be with whatever the power supply is supplying power to.

Is the power supply output shorted, or very low impedance?