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Discussion Starter · #1 ·
Hi Guys

I have a small single phase water pump motor around 450W, The motor did stall when it was working yesterday and is not working any more so i got a new one, I wonder if there is any kind of a motor stall protection that can turn off the motor when it has stalled ?
 

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quanchai said:
Hi Guys

I have a small single phase water pump motor around 450W, The motor did stall when it was working yesterday and is not working any more so i got a new one, I wonder if there is any kind of a motor stall protection that can turn off the motor when it has stalled ?
Install a tach and a plc program accordingly
 

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A little 450W pump, assuming single phase 120V type, is likely going to have a "klixon" internal thermal protector, which would eventually cool down and reset itself, or it is "self protected" which means that it has a smaller "fuse wire" built in that melts and opens the circuit before anything else catches fire. But once that wire melts, it's usually impossible to repair them, or impractical because they are too cheap. Assuming you have tried again after a while to run that pump and it still doesn't work, it's likely the self protected type. You need either a different pump with a klixon (which will say "internally protected" instead of self protected), or something that trips it off before that happens so you don't have to keep replacing it. So for that you could get a Current Sensing Relay and set it to trip at just an RCH above the rated amps, which if not shown you can assume is 450W/120V x .8pf, or around 3A. You will likely spend more for the relay than the pump is worth, so it's an issue of avoiding the hassle.

Oh, just saw that you are in Sweden, so 230V, so 1.6A
 

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quanchai said:
The Pump Is a centrifugal type, Why would the protector not work with it ?
What protector? Did you have one?
 

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Discussion Starter · #11 ·
No i dont have any protector but i am thinking about buying a motor protector, For what i know they all com in 3 phase is there any thing in single phase ?
 

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I pretwist and then use wire nuts. Solder pots rule.
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quanchai said:
No i dont have any protector but i am thinking about buying a motor protector, For what i know they all com in 3 phase is there any thing in single phase ?
We call them Tac switches over here.
Here is a picture.

Here is a link to the Square D catalog.
You will find single phase overload protection here. Also all the thermo heater element sizes you might need.

edit: first pic is the wrong one. Manual motor starter is the second one.
 

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I think the only reason we suggested the current sensing relay is due to the motor size.
450 watt motor is small and standard OL protection is slow.
 
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