Hi everyone

I am a long time lurker and first time poster. Firstly, that you to everyone for the great topics here. In my search for a solar solution this forum has helped me immensely in making informed choices.

We have serious water interruptions in our area so the solution for me is to attach my borehole to a Jojo for backup water. I currently have my borehole connected to irrigation running on a 32A smart switch.

I am thinking of T-ing the irrigation line so that I can run the borehole into the tank and control the borehole pump via a float switch to keep the tank level up. I will leave the system running to the tank and manually switch the pump on and select the ball valves in the waterline to run the irrigation.

The tank is about 60m from the borehole DB so I am thinking of using a relay to connect the float switch so I don't have to run the cable from the pump all the way there and back.

The next hurdle is that I only want the pump to be able to switch on between between 8am and 4pm as it's running on solar.

I think I need a relay with a manual override switch (so I can switch on the irrigation).

The way I see the wiring is as follows:
1. Breaker to smart switch (to energise the circuit between 8am and 4pm)
2. From smart switch to relay
3. From relay circuit to pump

Is this wiring correct? where can I find a 220v relay with a manual override?

Any suggestions would be appreciated 

Good afternoon @johnna and welcome to the forum.

 

I have read through your post and I have the following questions:

A] Brand and model of the 32A smart switch?

B] Does the borehole pump have a controller and a manual start and stop button?

C] The pump rating, voltage and if it is a single phase or three phase pump?

Once the above questions has been answered then suggestions can be made.

2 hours ago, johnna said:

The tank is about 60m from the borehole DB so I am thinking of using a relay to connect the float switch so I don't have to run the cable from the pump all the way there and back.

The float switches that I know have 3 wires one is a common wire, one in normally open and the other is normally closed, most of the time only 2 out of the 3 wires are used unless you want to use the normally closed contact of the switch to switch a light on in the borehole DB to show that the tank is full.

Kind Regards

GerhardK83

Hi Jonna and welcome

My question to you is the following.

Do you need an electrical float switch in the tank?

Use a mechanical float switch (like the old toilet filling valves) and T your irrigation system. The tank will automatically stop filling when full during irrigation. It will only affect the irrigation till the tank is full. If the flow is too high and affects your irrigation you can also throttle the flow to the tank with a gate valve.

Regards

Peter Topp

On 2024/11/29 at 11:46 AM, johnna said:

Hi Gerhard

The switch is a TO-Q-SY1-JWT from Takealot.

The borehole pump is on a standard breaker but now running through the smart switch.

As I understand it's a 750w single phase pump

 

Edited December 2, 20241 yr by johnna

Sorry, not sure what happened in the last reply😆

Hi Peter

I was thinking of using the electric float switch as I want to try and limit the cycling of the borehole pump. Basically want the tank to empty to about half full then switch on the pump

Edited December 2, 20241 yr by johnna

Good evening @johnna

Thanks for the feedback, is it possible that you can draw a rough sketch that indicate the physical location of the borehole the tank and the borehole DB?

Then you have not given an answer on the following question: B] Does the borehole pump have a controller and a manual start and stop button?

The reason for asking is that if it is a submersible borehole pump then the pump motor has two windings one is a start winding and the other one a run winding and the controller has two capacitors in it to create a phase shift in order to start the motor and the controller cannot be bypassed otherwise the motor would burn out.

The on button press a normally open switch momentarily which powers the coil of a contactor and once the contactor closes one of the contacts of the contactor is used to maintain the current flow through the coil which keeps the contactor closed. The off button is a normally closed switch which is wired in series with the coil power and once the button is pressed then the current flow to the coil is interrupted and the contactor open and the motor stop.

The contactor supplies power to the borehole pump controller and if that is known then it simplifies the design of the circuit in question.

Kind Regards

GerhardK83

10 hours ago, GerhardK83 said:

Good evening @johnna

Thanks for the feedback, is it possible that you can draw a rough sketch that indicate the physical location of the borehole the tank and the borehole DB?

Then you have not given an answer on the following question: B] Does the borehole pump have a controller and a manual start and stop button?

The reason for asking is that if it is a submersible borehole pump then the pump motor has two windings one is a start winding and the other one a run winding and the controller has two capacitors in it to create a phase shift in order to start the motor and the controller cannot be bypassed otherwise the motor would burn out.

The on button press a normally open switch momentarily which powers the coil of a contactor and once the contactor closes one of the contacts of the contactor is used to maintain the current flow through the coil which keeps the contactor closed. The off button is a normally closed switch which is wired in series with the coil power and once the button is pressed then the current flow to the coil is interrupted and the contactor open and the motor stop.

The contactor supplies power to the borehole pump controller and if that is known then it simplifies the design of the circuit in question.

Kind Regards

GerhardK83

Thanks Gerhard

The borehole does have a control box, the pump is switched on by the breaker on the DB. The smart switch was installed between the breaker and the control box (ie the breaker now stays on and the on off is controlled by the smartswitch)

Here is sketch of the layout, as you can see the the water tank where the level switch will be installed is quite a distance from the borehole DB. That is why I think using a relay switch will be a better option so that the pump "power" doesn't have to go around the house before powering the pump.

Good afternoon @johnna

Thanks for the sketch and the feedback.

I assume that the borehole switch is in the borehole DB, where does the borehole DB receive the power from?

Kind Regards

GerhardK83

Hi yes thats correct. The DB is on the lawn next to the lapa, it is wired as a sub DB from the main house

Ok, you stated that "it is wired as a sub DB from the main house" is that the same house as the one on the rough sketch or is there another house on the same premises?

Correct, sub db off main house, only 1 house on property

Ok, there are a couple of options depending on the scenarios as laid out below.

A] The borehole DB stays where it is currently situated and a trench is dug where the cable from the borehole DB goes to and back from the float switch which actuates the coil of a relay or contactor in the borehole DB.

The cable must either be an Armoured Cable or Surfix which is insulated and sheathed, if Surfix is chosen and the cable is buried at a depth of less than 500mm then the cable must be enclosed in conduit or otherwise be mechanically protected against damage by eg paving or concrete or be protected by an earth leakage protection device with a rated earth leakage current not exceeding 30mA.

If the Surfix cable is buried at a depth of more than 500mm then the backfill must not contain any sharp objects and there must be marker tape which runs above the cable route at a depth of between 300 mm and 400 mm.If a relay or contactor is used then the cable to and from the float switch can be the thinnest Surfix available because the current that the coil uses is small in comparison to the current that the contacts are switching.

B] If possible the borehole DB is moved to the side of the house so that the cable required to and from the float switch is much shorter and the same cable burrowing stipulations are adhered to as laid out above.

There must be a cable running from the borehole DB to and from the float switch because current cannot flow through air, there are wireless pump controllers available but some of them are about R6k.

9 minutes ago, GerhardK83 said:

Ok, there are a couple of options depending on the scenarios as laid out below.

A] The borehole DB stays where it is currently situated and a trench is dug where the cable from the borehole DB goes to and back from the float switch which actuates the coil of a relay or contactor in the borehole DB.

The cable must either be an Armoured Cable or Surfix which is insulated and sheathed, if Surfix is chosen and the cable is buried at a depth of less than 500mm then the cable must be enclosed in conduit or otherwise be mechanically protected against damage by eg paving or concrete or be protected by an earth leakage protection device with a rated earth leakage current not exceeding 30mA.

If the Surfix cable is buried at a depth of more than 500mm then the backfill must not contain any sharp objects and there must be marker tape which runs above the cable route at a depth of between 300 mm and 400 mm.If a relay or contactor is used then the cable to and from the float switch can be the thinnest Surfix available because the current that the coil uses is small in comparison to the current that the contacts are switching.

B] If possible the borehole DB is moved to the side of the house so that the cable required to and from the float switch is much shorter and the same cable burrowing stipulations are adhered to as laid out above.

There must be a cable running from the borehole DB to and from the float switch because current cannot flow through air, there are wireless pump controllers available but some of them are about R6k.

Thank you for the comprehensive reply! I really appreciate it

Ok wiring would be as follow:
The live output of the 32A Smart switch will be connected in parallel to the relay or contactor contacts and the common point of the float switch then the normally open contact of the float switch would be connected to the coil of the relay or contactor and the normally closed contact of the float switch can also be used to light up an indicator in the borehole DB to indicate that the tank is full or that the pump is not running.

You also stipulated that you want to be able to manually power on the borehole pump for irrigation purposes then you would need two additional switches or a change over switch, one to interrupt the current which is flowing through the relay or contactor coil and another to bypass the the float switch.

The reason why I suggest two additional switches or one change over switch are if the borehole pump is running filling the tank and you want to irrigate then you must be able to switch the pump off before changing any valves and for that you use the switch that interrupts the current flow to the relay or contactor coil, the other switch is used to bypass the current flowing through the float switch and power the borehole pump.

Have a look at the attached diagram I created.

S1 is the 32A Smart Switch
S2 is there to interrupt the current to the coil if you want to irrigate and the pump is running
S4 is the Float Switch
S3 is to bypass the float switch and to power the relay for irrigation
DS1 Indicates that the relay coil has power

I used the socket J1 as the output but that is where the borehole pump controller is connected.

S2 and S3 can be a 1 lever 2 way switch.

Float Switch.pdf

On 2024/12/07 at 1:33 PM, GerhardK83 said:

Ok wiring would be as follow:
The live output of the 32A Smart switch will be connected in parallel to the relay or contactor contacts and the common point of the float switch then the normally open contact of the float switch would be connected to the coil of the relay or contactor and the normally closed contact of the float switch can also be used to light up an indicator in the borehole DB to indicate that the tank is full or that the pump is not running.

You also stipulated that you want to be able to manually power on the borehole pump for irrigation purposes then you would need two additional switches or a change over switch, one to interrupt the current which is flowing through the relay or contactor coil and another to bypass the the float switch.

The reason why I suggest two additional switches or one change over switch are if the borehole pump is running filling the tank and you want to irrigate then you must be able to switch the pump off before changing any valves and for that you use the switch that interrupts the current flow to the relay or contactor coil, the other switch is used to bypass the current flowing through the float switch and power the borehole pump.

Have a look at the attached diagram I created.

S1 is the 32A Smart Switch
S2 is there to interrupt the current to the coil if you want to irrigate and the pump is running
S4 is the Float Switch
S3 is to bypass the float switch and to power the relay for irrigation
DS1 Indicates that the relay coil has power

I used the socket J1 as the output but that is where the borehole pump controller is connected.

S2 and S3 can be a 1 lever 2 way switch.

Float Switch.pdf 22.04 kB · 0 downloads

Hi Gerhard, thank you for your comrehensive input. I truly appreciate your help and the time you have taken to assist me!