Thread: Solar bore pump question

Water level sensors not connected?

Do you need to bridge them to common (WH to COM), to bypass?

(36v non well / non tower diagram)

Originally Posted by d@rk51d3

Water level sensors not connected?

Do you need to bridge them to common (WH to COM), to bypass?

(36v non well / non tower diagram)

This box does not have the WH WL WC terminals.
It has the TL TM & TH terminals to stop the tank from overflowing.
I asked the father before he died about probes in the bore for low level and he said these pumps dont need them as they turn themselves off.
I thought that might be what the third pump wire is for. The diagram is not clear.
The book mentions bridging the WH & WC but no mention of doing it to any of the T terminals.

Strange.

I can't see the purpose for 3 tank sensors, and according to the manual there should only be a TL (COM) and TH. When the tank is low, pump cuts in. When the tank is full, the water bridges the 2 sensors and cuts it off.

Only the well has three, Standing water level (HW), working level (LW) and the Common (WC).

I'm starting to think it's a chinglish error, someone has borked the label, and as the manual states, if there's no sensors in the well, you'll need to bridge WH and WC for the pump to run. (or TL and TH in your case if they've mislabeled the terminals)
BUT you'll lose LOP protection (loss of prime) if the well level drops, pump will run dry.
Also, pump can't turn off if there's no sensor, pressure switch, float switch, to signal it to stop............. until the sun goes down and drops power to the whole shebang..

BUT(2), I'm only guessing.

I think you've got a bit of a mis match of gear.

For a start, your panels are 'nominally' 18 volt (just to make them different), but that's OK, connected in series you get 'nominally' 36 volt which should run your pump motor.

What is an issue though is the power rating of the panels. They're rated at 100 watt each, not the 130 watt specified for the 36 volt pumps. Also as a 18 volt panel I reckon they're a bit under rated in the voltage stakes as well. I would expect a Voc of around 33 volt and a Vmp of around 27 volt to give a bit of overhead to the system, but they may run at this lower voltage so as not to overload the regulator/controller input.

I assume when you're testing this that it's nice and sunny with the panels pointed to the sun . You can hear the pump start but it turns off straight away, so either it thinks a/. the bores dry or b/. the tanks full or c/. there's not enough grunt from the panels to drive the pump. (or the whole things totally stuffed which I don't think it is.

As a test I'd suggest getting 3 car batterys, connect them in series to give 36 volts (nominal) and connect this to the reg instead of the solar panels (please use a fuse here just in case). If it all works OK then the problem is probably undersized panels.

If this doesn't work I'd try connecting the TM (tank common) and TL(water low) terminals together, the theory being that this will tell the pump to start as opposed to connecting TM and TH (tank high) which I'd expect to tell the pump to turn off.

Hope that makes some sense.

Deano

Like you I cant see the need for 3 tank sensors either.
Bore probes yes. The Grundfoss I had in there had the three.

The father said it would turn off if the level got below the pump unlet. Could there be a probe built in?
What would the 3rd wire be for if its just a simple dc motor?

Then again if it was a probe wire it would not be bundled with the power wires.
The manual also say to reverse rotation switch any two wires of the three.
Confuses me, why would you want to run it in reverse anyway.

Originally Posted by DeanoH

I think you've got a bit of a mis match of gear.

For a start, your panels are 'nominally' 18 volt (just to make them different), but that's OK, connected in series you get 'nominally' 36 volt which should run your pump motor.

What is an issue though is the power rating of the panels. They're rated at 100 watt each, not the 130 watt specified for the 36 volt pumps. Also as a 18 volt panel I reckon they're a bit under rated in the voltage stakes as well. I would expect a Voc of around 33 volt and a Vmp of around 27 volt to give a bit of overhead to the system, but they may run at this lower voltage so as not to overload the regulator/controller input.

I assume when you're testing this that it's nice and sunny with the panels pointed to the sun . You can hear the pump start but it turns off straight away, so either it thinks a/. the bores dry or b/. the tanks full or c/. there's not enough grunt from the panels to drive the pump. (or the whole things totally stuffed which I don't think it is.

As a test I'd suggest getting 3 car batterys, connect them in series to give 36 volts (nominal) and connect this to the reg instead of the solar panels (please use a fuse here just in case). If it all works OK then the problem is probably undersized panels.

If this doesn't work I'd try connecting the TM (tank common) and TL(water low) terminals together, the theory being that this will tell the pump to start as opposed to connecting TM and TH (tank high) which I'd expect to tell the pump to turn off.

Hope that makes some sense.

Deano

The panels the son offered me are the 19volt ones.
These ones are VOC 27.8 and Vmp 23volts.
Got to go out now. I will try bridging the terminals tomorrow.

Originally Posted by 123rover50

.....................Like you I cant see the need for 3 tank sensors either.
..............................

May have misread the L M H as Low, coMmon and High. Are these single wire capacitive/conductive sensors ?

It may be that with an empty tank (no water contact between TL & TM) that the pump is run flat out by the controller but when these contacts are bridged by the water that the pump is slowed down a bit until TL, TM and TH are bridged which turns the pump off.

Deano

3 sensors in the tank would work similarly to 3 in the well, but in reverse. But a wasted exercise for general use, I think.

In the well, if the water covers all 3, the pump will run until either the tank sensors show full and shuts it down, or the water level in the well drops below the second well sensor. (m)

If water in the well drops below the second well sensor (m), the pump cuts out, and will not restart until the well shows full by reaching the 3rd sensor (h) again.

So, with no sensors in the tank, controller will read the tank as empty, and should be signalled to run, BUT with no sensors down the well, it will register as a dry bore, and refuse to start the pump.

Looks like you need to trick the controller into thinking there's water in the well (bridging the common (L) and (H)igh sensor terminals). A sensor in the pump itself would be insufficient IMHO, as the pump would possibly vortex and suck air.