Solar Pump automatic

[Thaifish]

@Crossy I happened to be chatting with @MJCM on another platform and not aware of this thread but discussing the same. I think I am on MJCM's mailing list for x-mass cards this year with his 12v Solar pump switch issue.  This system works when there is a long way between Solar pump and storage tank without wires...There is a simple pressure switch near the pump which is adjustable and a float in the storage tank. When the pressure reaches the set limit the switch turns off. Keep it simple stupid.

 

https://www.commodoreaustralia.com.au/product/pressure-kit-for-solar-dc-pumps-without-tank/

 

 

On another note comparing prices with contractor installation and buying of the shop floor is a huge difference. 178,000bht 5Kw solar system Global compared to 83,000bht Godungfaifaa for similar setup in a kit. Thai company. I think from Surin near Pattaya

 

[Crossy]

@Thaifish yes, but!

 

The "but" being that it uses the "tank sensor" input on the solar pump controller, we don't know if @MJCM controller has such an input.

 

If it does he's home 'coz a regular pressure switch would do the trick, if it doesn't he will need a DC rated switch or some electronics (solid state relay) to control the pump.

 

[Thaifish]

14 hours ago, Crossy said:

The "but" being that it uses the "tank sensor" input on the solar pump controller,

I see that now you pointed it out. So much for my x-mass card.

[MJCM]

On 12/4/2021 at 5:07 AM, Crossy said:

@Thaifish yes, but!

 

The "but" being that it uses the "tank sensor" input on the solar pump controller, we don't know if @MJCM controller has such an input.

 

If it does he's home 'coz a regular pressure switch would do the trick, if it doesn't he will need a DC rated switch or some electronics (solid state relay) to control the pump.

 

Thx Guys and @Thaifish you are still on my Christmas Card list ????

 

I have been looking all over, already called the BIL (because he took the Wooden box the Pump came in) and NO Manual to be found!!

 

Oke question:

 

My idea is if my controller doesn't work, can I buy another controller (that has this option for sure) or is the controller linked to the pump??

[Crossy]

2 minutes ago, MJCM said:

My idea is if my controller doesn't work, can I buy another controller (that has this option for sure) or is the controller linked to the pump??

 

You would need a controller matched to the pump voltage/current.

 

Is there a visible manufacturer / model number on the controller? Can you post a photo of the controller terminals / labels?

 

We should be able to come up with some simple electronics to control the pump even if you can't get a DC pressure switch (at low energy levels a regular AC switch will be fine).

[MJCM]

Thx DC.

 

Next time I do the walk ???? I will take the pictures you asked for

 

 

[SomchaiDIY]

1 hour ago, MJCM said:

Thx Guys and @Thaifish you are still on my Christmas Card list ????

 

I have been looking all over, already called the BIL (because he took the Wooden box the Pump came in) and NO Manual to be found!!

 

Oke question:

 

My idea is if my controller doesn't work, can I buy another controller (that has this option for sure) or is the controller linked to the pump??

Your control has same front panel setup as control in my video. Many brand of these solar pump use same system with only different box label and style.

 

I am very sure there are level control connections in your box. These you can use with pressure switch also if required.

 

Should be very simple procedure to modify your system.

[Thaifish]

Does this work?? I think it would...!! 12v Murphy Liquid Pressure gauge with a magnetic switch. Once preset pressure is reached it cuts the power supply to motor.. No need to go through the controller.  The pump is more than likely a low pressure centrifugal style so the Murphy gauge can be set anywhere from 0 bar/psi upwards. There will be back pressure due to length of pipes anyway. The holding tank needs a simple float switch to stop the water so when its full the increased back-pressure in the pipe trips the Murphy.....? 19 days till x-mass....

 

https://www.fwmurphy.com/products/gages/20p-25p-series

 

Edited December 6, 2021 by Thaifish

[MJCM]

On 12/5/2021 at 5:00 PM, SomchaiDIY said:

Your control has same front panel setup as control in my video. Many brand of these solar pump use same system with only different box label and style.

 

I am very sure there are level control connections in your box. These you can use with pressure switch also if required.

 

Should be very simple procedure to modify your system.

Thx, Very simple for you ???? But not for me, I am not that technical sorry.

 

I still have to find the manual of the Controller pump already talked to the shop if they can find me one

[MJCM]

15 hours ago, Thaifish said:

Does this work?? I think it would...!! 12v Murphy Liquid Pressure gauge with a magnetic switch. Once preset pressure is reached it cuts the power supply to motor.. No need to go through the controller.  The pump is more than likely a low pressure centrifugal style so the Murphy gauge can be set anywhere from 0 bar/psi upwards. There will be back pressure due to length of pipes anyway. The holding tank needs a simple float switch to stop the water so when its full the increased back-pressure in the pipe trips the Murphy.....? 19 days till x-mass....

 

https://www.fwmurphy.com/products/gages/20p-25p-series

 

Thx Fishy.

 

One question though (excuse my ignorance and maybe a stupid question) this would cut power to the Pump only correct?

 

But then the Solar panels would still be "working". Isn't that harmful for the panels / controller?

 

I now just "flip a switch" and both the Controller and the Pump turn completely off.

[Crossy]

Personally I would place any controlling element in line with the existing switch, we know that won't hurt the panels or the controller.

 

Any news on the controller type / connections??

 

One issue you will have with any type of relay will be the large voltage range it will need to operate over, I suspect a solid-state relay would be a better choice than anything electromagnetic.

 

EDIT How many panels do you have, are they in series or parallel, what is the open-circuit voltage of each panel, short circuit current (all will be on the back of the panel)?

 

With that info I can design you something that would work with a regular AC pressure switch.

 

 

[Crossy]

29 minutes ago, Crossy said:

Personally I would place any controlling element in line with the existing switch, we know that won't hurt the panels or the controller.

 

Any news on the controller type / connections??

 

One issue you will have with any type of relay will be the large voltage range it will need to operate over, I suspect a solid-state relay would be a better choice than anything electromagnetic.

 

EDIT How many panels do you have, are they in series or parallel, what is the open-circuit voltage of each panel, short circuit current (all will be on the back of the panel)? What's the rating of that breaker (switch)?

 

With that info I can design you something that would work with a regular AC pressure switch.

 

 

 

[MJCM]

answers within your post

35 minutes ago, Crossy said:

Personally I would place any controlling element in line with the existing switch, we know that won't hurt the panels or the controller.

 

Any news on the controller type / connections??

Nope Sorry not yet. But I send an email to the shop asking for a manual! Also we Haven't been that well, the cold weather is affecting us (happy with our 15cm Diamond AAC Blocks (or whatever they are called) as it keeps the cold out!!)

 

35 minutes ago, Crossy said:

 

 

EDIT How many panels do you have, are they in series or parallel, what is the open-circuit voltage of each panel, short circuit current (all will be on the back of the panel)?

 

With that info I can design you something that would work with a regular AC pressure switch.

 

 

We have 3 panels. And if they are in series or in parallel and all the other questions, I have NO .... idea. ????

 

I just told the shop I want a Solar pump that pumps water from the lake to the tank and how much it costs. They did everything and the only 2 things I did was A) I paid them B) asked the "stupid" question if it could be made automatic and that is how I got here ????

[Crossy]

OK, I'll guess they are in series (from the pump spec.) and they're probably V-OC less than 50V, I-SC less than 10A.

 

So we're looking at something to control 200V @ 20A or so. 

 

The cold is getting us here in BKK too, the dogs are actually waiting to have their coats put on tonight.

[MJCM]

 

4 minutes ago, Crossy said:

OK, I'll guess they are in series (from the pump spec.) and they're probably V-OC less than 50V, I-SC less than 10A.

 

So we're looking at something to control 200V @ 20A or so. 

 

The cold is getting us here in BKK too, the dogs are actually waiting to have their coats put on tonight.

DC and all other contributors

 

Thx for all the efforts but it is a good exercise for you and other techies but for me difficult so I will keep walking!! Good exercise as well (and no need to walk when it's raining because it's for the garden only)

 

I now know it's definitely possible to do but I am just wondering why these installers don't know!

 

I hope this thread solves the problem for someone else who is having the same issue!!