Two Pumps in the Desert

[waleed]

Hello ,

I have two pumps , which I want only one to be ON at any given time. The pumps are triggered by several event , i.e. tank empty , irrigation pressure (manual open one of the valves) , irrigation controller.. etc.

I am thinking of using two ON delay timers with say 2 min. on delay on each pump , the timer will connect to the AB of the pump contractors. Now if the input to the timer X is on , the other will be off and vice versa.

So if one of the pumps (well) is already on , and I tried to switch on the other pump (booster) , the well pump will be immediately switched off and the booster pump will be on after 2 min.

Will this work ? Is there a better way to control the pumps ?

Many thanks for such great forum and great people ..

 

[Knobhead]

If you’re going to control the pumps by a one ON, one OFF system you can dispense with the switch over delay.

 

[rapparee]

All you need is a n/o n/c contactor

 

[Charlie_]

How many possible events are there?
Are you familiar with PLC's?

 

[Engineer54]

How many possible events are there?
Are you familiar with PLC's?

The last thing you'd want to do in Saudi, is to complicate things. This installation is already suffering from other problems, outlined in another thread by the same OP!!

 

[davesparks]

Keep it simple, put a changeover switch in!

 

[Charlie_]

The last thing you'd want to do in Saudi, is to complicate things. This installation is already suffering from other problems, outlined in another thread by the same OP!!

Whats with all the exclamation marks?? Are you actually shouting whilst typing??
Obviously i'm not aware of any other issues which is why I asked the number of possible events..

 

[ifindoubtdont]

I assume you have a header tank/reservoir, if this is the case use a run till full float for that and use solenoid operated valves to divert the water to where you it.

 

[Marvo]

Usually we supply a booster pump via its own safety low-level controller to prevent dry run, we also use this control to activate any alarms required. We fit a separate level controller for the borehole pump that fills the tank. we sometimes also interlock the borehole pump with the low-level safety control unless there's probes down the borehole itself.

 

[Knobhead]

All you need is a n/o n/c contactor

Care to explain?

 

[rapparee]

Care to explain?

One pump on n/o the other on n/c they'd never be on at the same time.


Obviously i mean the n/o n/c are used to control the coil on seperate contactors for each pump with appropriate motor overload protection etc

 

[Marvo]

One pump on n/o the other on n/c they'd never be on at the same time.

And if the control side blows a fuse one of the pumps runs continuously.

 

[rapparee]

And if the control side blows a fuse one of the pumps runs continuously.

Well if we are assuming that the control circuit goes down, then neither the n/o or n/c feed is energised and neither pump contactor will pull in.

 

[Silly Sausage]

Well if we are assuming that the control circuit goes down, then neither the n/o or n/c feed is energised and neither pump contactor will pull in.

Aye, Fail Safe.
Then an alarm is sent to the locals to get out there and start cranking that Archimedes' screw.

 

[waleed]

If you’re going to control the pumps by a one ON, one OFF system you can dispense with the switch over delay.

Would you kindly link a sample switch over delay from Schneider or ABB .. etc ,thanks