How to wire a float switch to DC and AC supply at once

[Houtos]

Hello,
I want to power the water pump with two different power supply, from the solar panel (DC) and from the electrical supply (AC). both should be activated with a float switch at different times. during the day it should be solar and at night it should be AC supply automatically. what do i need to make it work?

 

[SparkyChick]

I think it's unlikely a single float switch will do this for you.

Can you provide some more details about the installation showing the supply arrangements to the water pump?

 

[davesparks]

You will need to put together a small control panel which incorporates switching between the two supplies, the float switch input, any safety devices required, any protective devices required etc etc

You can't simply supply a float switch with two supplies and make it work, there needs to be some control system to decide between the supplies and then switch them appropriately.

 

[Spoon]

If I'm reading you post correct, you will need a timer to switch between the two supplies. This then feeds to the float switch and then to the motor... This is put in very simple terms.
As above, you will need additional equipment, mentioned by @davesparks
As @SparkyChick has mentioned, please give more info. The more the better.

 

[davesparks]

If I'm reading you post correct, you will need a timer to switch between the two supplies. This then feeds to the float switch and then to the motor... This is put in very simple terms.

As one of the supplies is solar PV it may be possible to set up a priority system so that it switches to the solar supply whenever it is generating without using a timeswitch.

 

[James]

Have you considered 2 float switches?
bottom float to run solar power pump,
1 extra, slightly above the first that runs on ac.

priority will always be to the solar pump but if that fails due to lack of sun or any other reason, when the level gets a little higher the ac pump will be activated.

 

[davesparks]

Have you considered 2 float switches?
bottom float to run solar power pump,
1 extra, slightly above the first that runs on ac.

priority will always be to the solar pump but if that fails due to lack of sun or any other reason, when the level gets a little higher the ac pump will be activated.

This is assuming that this is pumping out of a tank when it is full, it could also be pumping in to a tank as it empties.

 

[James]

This is assuming that this is pumping out of a tank when it is full, it could also be pumping in to a tank as it empties.

correct, however the same principal can be applied for either situation, by swapping the float switch positions.

 

[davesparks]

correct, however the same principal can be applied for either situation, by swapping the float switch positions.

Only if the first pump supplies water at the same rate, or higher, than it is draining at. Otherwise both pumps would then start at the same time.

It's almost like the OP has given next to no information about the setup and expects us all to look in our crystal balls!

 

[James]

childish giggle

he said balls !!!

 

[Megawatt]

Hello,
I want to power the water pump with two different power supply, from the solar panel (DC) and from the electrical supply (AC). both should be activated with a float switch at different times. during the day it should be solar and at night it should be AC supply automatically. what do i need to make it work?

Houtos welcome to the forum and what you need to do is let the float control a relay with 2 sets of contacts 1 set would be NO and the other set should be NC and that will work.

 

[DefyG]

Houtos welcome to the forum and what you need to do is let the float control a relay with 2 sets of contacts 1 set would be NO and the other set should be NC and that will work.

Agreed, DC Relay DPDT, no need to over complicate it with 2 pumps, 2 float switches.

 

[James]

Agreed, DC Relay DPDT, no need to over complicate it with 2 pumps, 2 float switches.

missing the point here.

there is not in existence as far as I know a pump that will run on dc or ac

by definition, we must be looking at a system that has 2 pumps?
1 dc possibley 12 or 24v
1ac possibley 230v

it is over complicating matters to use a relay and time clock to decide which pump to opperate.
also, the control voltage for the relay will have to be considered, depending on the importance of the pump working at all times required.

what could be simpler than float 1 controls pump 1 and float 2 controls pump 2?

if you use a relay then you will loose power to both pumps if the supply to 1 pump fails (assuming it is the supply to the control relay too.)

 

[davesparks]

Houtos welcome to the forum and what you need to do is let the float control a relay with 2 sets of contacts 1 set would be NO and the other set should be NC and that will work.

How will that work?

 

[DefyG]

missing the point here. - It would help to know more about the application.

there is not in existence as far as I know a pump that will run on dc or ac - Agreed

by definition, we must be looking at a system that has 2 pumps? - Disagree

1 dc possibley 12 or 24v1ac possibley 230vit is over complicating matters to use a relay and time clock to decide which pump to opperate. - I didn't mention a time clock. The solar panel would activate between dawn and dusk eliminating need for a time clock

also, the control voltage for the relay will have to be considered, depending on the importance of the pump working at all times required. - The relay coil would be DC (powered by the pv panel, subject to coil voltage being compatible) switching the AC supply to THE 230v pump. During hours of darkness the relay switches over onto the NC contacts (ie relay coil not energised) maintaining the AC supply to the pump.The ONLY float switch needs to be between the relay output and the pump.

what could be simpler than float 1 controls pump 1 and float 2 controls pump 2? - Consider cost of an unnecessary (in my opinion) second pump.

if you use a relay then you will loose power to both pumps if the supply to 1 pump fails (assuming it is the supply to the control relay too.) - Loss of power (supply or component) can happen at any time, irrespective of system used.

Source URL: How to wire a float switch to DC and AC supply at once - https://www.electriciansforums.net/threads/how-to-wire-a-float-switch-to-dc-and-ac-supply-at-once.185708/#post-1625086

 

[Houtos]

GRUNDFOS SQFLEX that is the name of the pump,
The pump is fitted with a highefficiency motor for DC and AC voltage. SQFlex is more than just a pump – it's a complete intelligent system. Thanks to its built-in electronics, the pump is compatible with both DC and AC power supply without requiring an external inverter. i got this statement from their website

 

[James]

ok,
this is a specialist application that is beyond the realms of a simple relay or switch solution.
I suggest that you purchase one of the recommended control solutions from the manufacturer.

https://net.grundfos.com/Appl/ccmsservices/public/literature/filedata/Grundfosliterature-1663877.pdf

 

[DefyG]

what could be simpler than float 1 controls pump 1 and float 2 controls pump 2? - Consider cost of an unnecessary (in my opinion) second pump.

especially now knowing the cost of the ones the OPs intending to use.
It Would have been more helpful knowing pump type information at the start of the thread! but then again had the OP done his homework and found this out to start with, there wouldn’t have been a need for a thread at all!