NEED AC water pump PROJECT HELP

OnMan

Joined May 15, 2021
10
Hello incredibly smart people! I have a general idea of electronics and wiring but once math, terms, and knowing exactly what I need gets involved I am completely lost. This is where this community comes into play.

Project:
So I have an AC motor, AC water pump, and small contact switches that I need to work in conjunction with eachother. The entire circuit should be wired to work with a 120V AC outlet (plug).

Process: When Contact Switches make contact, the motor and water pump shall run for 50 seconds and then turn off, awaiting the next time that the switches make contact.

What I'm sure of: I'm sure I will have to write an extremely small code for this but I have no idea where to start. I do have an Arduino Mega 2560 R3 but that runs off of a usb, which is DC as far as I understand so I would have to rig something up. Unless someone has a better idea or piece of technology to buy. I am trying to keep this as simple and small in size as possible.

The attachment below has all the specs and is somewhat of a diagram.

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MrChips

Joined Oct 2, 2009
30,497
You go and by a timer relay such as this:

or this:

MisterBill2

Joined Jan 23, 2018
17,829
OK, I will start with a guess that the witch contact closure that starts the 50 second shower is always less than the 50 second, and that each sequence must end before the next one can begin.
If I design the input to be a short pulSe, no matter how long the closure, and have that trigger a latching relay circuitthat runs a timer and a motor control relay, the job is half done. When the timer reaches the full time, 50 seconds, it's contact switches off both the motor and the timer. Then it is ready for the next cycle.
Does that description match the desired function???

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OnMan

Joined May 15, 2021
10
You go and by a timer relay such as this...
Awesome and how would you wire it all together to work correctly?

OnMan

Joined May 15, 2021
10
OK, I will start with a guess that the witch contact closure that starts the 50 second shower is always less than the 50 second, and that each sequence must end before the next one can begin.
If I design the input to be a short pule, no matter how long the closure, and have that trigger a latching relay circuitthat runs a timer and a motor control relay, the job is half done. When the timer reaches the full time, 50 seconds, it's contact switches off both the motor and the timer. Then it is ready for the next cycle.
Does that description match the desired function???
Yes that sounds right. As long as the contact switch is triggered (short or long time) then it will turn the electric motor and the water pump on to both run for 50 seconds. After 50 seconds they will shut off and be ready for the next trigger from the contact switches

MisterBill2

Joined Jan 23, 2018
17,829
ok, NOW FOR THE WIRING. Two considerations, first, I hope that all of the switches are momentary action, and so that they do not stay closed for more than the 50 seconds. Otherwise it would get a bit more complicated. And second, that the switches are OK to switch the mains voltage, 120 volts AC. Otherwise, there would need to be a small DC power supply included. That adds some complexity and a bit of expense, because of the power supply.
The timer needs to have a contact connection that is only closed when the timer is doing the time cycle.
And there needs to be a control relay with two sets of contacts adequate to switch the pump motor on and off. So based on the listed pump motor current, the relay needs 5 amp contacts, at least, and a 120 volt coil that draws LESS THAN 0.2 amps.
So there is the list of components.
Now comes the circuit description, because I still do not have my CAD computer repaired. I will call the 120 volts source Line and Neutral, and the terminals of all the two-terminal devices terminal 1 and terminal 2, or T1 and T2 (device name) , and the relay will have contacts A and B,both normally open.
First, the motor control part: the line connects to relay contact A,T1. The motor T1 connects to relay contact A,T2, motor T2 connects to relay contact B T2,relay contact B T1 connects to neutral. so that whan the relay operates the motor runs. When the relay is off, the motor is disconnected.
Next, The (small contact switch) T1 connects to Line, (small contact switch)T2 connects to the relay coil T1, and relay coil T2 connects to neutral, so that when (small contact switch) closes the timer runs. Timer contact T1 also connects to line, and timer contact T2 also connects to relay coil T1, so that while the timer is timing the relay coil stays on.
Timer power connection T1 connects to relay coil connection T1, and timer power connection T2 connects to relay coil connection T2. So the timer runs as long as the relay is operated. If the (small contact switch) contacts have opened before the timer contacts open, the motor will switch off when the timer reaches 50 seconds. That should be all of the circuit needed.
Of course, the (small contact switch) contact must stay closed long enough for the timer contacts to close, in order for the circuit to work.

OnMan

Joined May 15, 2021
10
You are a savior sir, thank you for taking your time out of your day to fully explain and lay that out to me. And yes the contact switches should only stay closed for about 4 seconds. I'm going to go buy everything and if I need any extra help then I will definitely come and ask you if you don't mind! Thank you again!

OnMan

Joined May 15, 2021
10
I do now notice that there may be a confusion, the motor and the water pump are 2 seperate pieces of the circuit. So in all I have a water pump motor, contact switches, and then the electric motor.

OnMan

Joined May 15, 2021
10
Unless you did include that and I'm just misunderstanding.

MisterBill2

Joined Jan 23, 2018
17,829
I had presumed that the motor provided the drive for the water pump. If the water pump is a single device then when I used the term "motor"it was intended to mean the motor integral to the water pump assembly. The pumps that I am familiar with are separate from the motors that drive them. Sorry about causing a bit of confusion there.
And it will be very interesting to discover what others visiting will think of my circuit description. Some folks are not very good about visualizing stuff.

OnMan

Joined May 15, 2021
10
Ah yes then we were on a different page than eachother. The ac motor is to drive a shaft, the water pump has its own built in motor, hence the two different set of specs in my drawings. Would this change the circuit you described or would I just wire the two motors together and then wire them into the circuit. Because both the water pump and shaft motor will run for 50 seconds.

MisterBill2

Joined Jan 23, 2018
17,829
OK, the one part that might change would be that relay and it's contact ratings.
The concern is that most motors draw much more current during those first few instants as they reach running speed. And unfortunately, as relay contact ratings increase, relay coil currents also increase. So at some point you may need to have the smaller relay power a larger relay to switch on the water pump and the motor.

OnMan

Joined May 15, 2021
10
Understood, I'll keep that in mind, the motor for the shaft is only 2 rpm so it's not fast and the water pump doesn't pump that much water via gpm so I think I'm good there.

MisterBill2

Joined Jan 23, 2018
17,829
Understood, I'll keep that in mind, the motor for the shaft is only 2 rpm so it's not fast and the water pump doesn't pump that much water via gpm so I think I'm good there.
OK, I only had he one currentvalue of 2.3 amps. A small motor should not draw much additional current.

OnMan

Joined May 15, 2021
10
No it shouldn't, I agree. I know I might be asking too much but is there any way you could list the exact components needed (size, specs) and draw up a small wiring diagram for me to go off of, like I said, I have very little knowledge in the exact process of wiring everything up correctly and I would appreciate it massively. Attached below are the parts in using. The pump, motor, contact switches.

MisterBill2

Joined Jan 23, 2018
17,829
OOPS, I see a possible problem, which is the voltage rating of that switch. 100 volts AC or DC. The max current listed as 0.5 amps, which should be OK, but the voltage rating is a concern.
The simple work-around would be to add a 24 volt transformer to supply the timer and the relay, with the transformer's 24 volt terminals replacing the connections to line and neutral for the timer and relay circuit.
The size of the controls section would be a bit larger and the system would now consume a bit of power all the time, other than that, no down side.
Quite probably another participant can produce the schematic drawing, since I have not repaired or replaced my cad-software computer yet.
I will need to do a bit of looking to find the best value timer, as that will be the expensive part of the project.

And really, the circuit could easily be built up straight from that description that I provided.