Yet another Uphill water pumping Situation :) -PART 2 1

[congoRiver]

thread164-459801

Hello guys

Following the valuable guidances on my previous thread, we finally installed this pump that we found on Amazon UK:

We also installed 6 x300W solar panels and 2 x 12v 200ah gel batteries (bought at a local store)

However, after 3 months of using the batteries as the only source for pumping, they totally lost their capacity. We have ordered new set of batteries from Europe and we expect them to arrive by boat in 6weeks.

My new question will be: Is it possible to run the pump directly from the solar panels? If yes how does one connect it?
(local advices haven't been 100% reliable so far)

 

[LittleInch]

Not possible to really say without a full description and circuit diagram of your set up.

However it should be feasible as the power isn't that big and I assume that red box is the invertor.

You might need to reduce the number of solar panels but I don't know whether having more power available than you need is an issue or not.

The batteries really just smooth everything out but if they only lasted 3 months it might be your charging system isn't properly set up.

Is a lot more complex than it looks to get an isolated solar panel system to work effectively

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IRstuff]

There are a few issues
> Alibaba shows the exact same model pump with only 116-m head

which raises the question how much head it can actually handle; but moreover, it determines how hard the pump is actually working and how much power it's consuming
> While you've ostensibly gotten 1800W of solar panels, that's the ABSOLUTE MAXIMUM they can generate, given peak solar radiation, which only exists for a couple of hours a day. The fact that you're close to the equator certainly helps, but overcast, clouds, etc. diminish the generation capacity.
> I question whether the panels are actually 300W panels, since the typical is more like 250W/panel
> How long have you been pumping per day? If it's more than 4 hrs AND you have less than 100% sun EVERY day, then the solar and battery systems might be undersized.
> I don't understand why you've only been running on battery; why are the panels doing the bulk of the work?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[congoRiver]

As mentioned on my previous post, we are very new at solar with no technical background whatsoever. We have embarked in this journey and learning along the way >>

https://www.youtube.com/watch?v=WMS4qJ7pYZw

Re. set up, I trusted that the local company would set up so that panels would do the most of the work but we noticed later on that the pump was only running on batteries ( 3 hours and 3 x week) where we actually wanted the batteries as backup for less sunny days.

It is now that the batteries have died that we want to know whether we can change the set up and allow the solar to do the work (even 1h/day - 7/7 would be ok).

If we need to reconfigure the set up and if it is a feasible option, what is the set up diagram you would recommand?


thanks !

 

[GeoEnvGuy]

The answer is in the solar battery controller. I have limited experience but I have a remote monitoring system that was running off the solar panel and dying every night until someone changed the fuse to the battery.

 

[itsmoked]

Your system has failed because you provide no way to stop the pump if there is no available solar.

Further you can not just stop the pump with lack of solar you must also shut off the inverter as it presents a considerable standby load to the DC supply (battery bank) simply sitting there ON.

To fix this you need to harness a likely function of the solar charge controller you already have. The last two terminals (not connected) are typically "Load" terminals. They output whatever the battery voltage is when certain conditions are met. The condition you need to be available is the condition "solar power available" which is a common mode for applications like you're trying to do.

You would hook up a standard ice-cube relay's coil (same voltage rating as the battery bank) to the LOAD terminals so when the terminals are active the relay operates closing its contacts.

Next, disconnect the positive battery cable to the inverter.
Now you need to open the inverter cover where the power switch is.
Find the power switch.
Cut one of the wires going to the power switch.
Wire the now two wire-ends of the cut switch wire thru a set of normally open contacts on the aforementioned relay.
If the relay closes AND the inverter power switch is ON the inverter would startup and run.
Program the charge controller to the mode that energizes its LOAD terminals if solar is available.

Reconnect the battery to the inverter (don't mind the spark that will occur).

Now when the sun shows up for something like 30 seconds the charge controller LOAD output will turn ON.
This will close the relay.
That will complete the ON/OFF circuit in the inverter (if you have the inverter power switch in the ON position)
The inverter will startup.
If the water tank calls for water the pump will have inverter power to run.
If a cloud comes by and reduces the available power to the charge controller for more than 10 seconds (usually) the charge controller will shut off the inverter (via the relay) preventing it from loading the batteries and of course stopping the pump as required not loading the batteries. If the clouds go away for more than 30 seconds (usually) the charge controller load output will activate restarting the inverter which will pick up where it left off.

If the tank stops calling then everything stays waiting with power available for the float switch to run the pump when needed.

Because the described setup never pumps when the solar energy isn't available the batteries need supply almost no energy. They simply anchor the system DC voltage. Your clapped-out mistreated batteries could still get the job done if they have a couple amp-hours of capacity.

I'd implement this and if it works as expected I'd then replace the batteries as more capacity will reduce wear and tear on all the other equipment because the battery bank will more rigidly anchor the voltage. If the batteries completely fail your inverter will fail immediately also so don't leave seriously screwed up batteries in service here.

Notes:
The inverter might have external screw terminals to turn it ON/OFF so you might not have to hack it. They would've essentially hacked it already.

You need to understand what I've described and be capable of executing these instructions safely. If you can't, find someone with the requisite skills to help you, preferably a local who can help support the system. Learn not to burn!

The above description is strictly for supporting just a pump. If other loads are needed then other details would be required and could completely derail the above instructions.

Use a relay with an indicator lamp and a manual-operate flag to assist with future trouble shooting.

DO NOT ALLOW POWER to the inverter from a solar array not hooked to a battery bank. Disconnect the array/charger before disconnecting the battery bank.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[LittleInch]

congo,

Take note of keiths post - very good.

However looking at your last post and the video can you confirm the head height (you said ~70m) and what sort of flow rate you're getting, i.e. how long does it take to fill the tank assuming you know what volume you have.

That pump you have is a single screw shaft which looks very much like a progressive cavity pump - a form of a PD pump.

The markings on the top indicate a flow of 1.2m3/hr, head of 100m and power of 0.75 kW.

How they get the other figures I don't know, but maybe they just screw the inbuilt pressure relief valve down a bit more. The point is that I think you're maybe drawing a lot more than 750W. If you are then your motor won't last very long.

When it works you really should measure the current going through this motor. At 240V it shouldn't be above 3 amps.

The difficulty you have from running only on solar is that you might not have enough power to run the motor properly other than at peak solar hours of the day. If the motor stalls or runs very slowly you will probably destroy it. Pumps often draw more power than running to start so if you don't have batteries to give it the initial start current, it won't start properly.

How did you know the pump was only running on batteries?

Your key is obtaining the operating manual for that solar battery charger you have. What is its make and model number??

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[itsmoked]

congoRiver: Did you get any of this?

Keith Cress
kcress -

http://www.flaminsystems.com