Electrical Question Water Pump

[TexasRanger]

I just replaced my well pump with exactly the same model, the problem is that an electrician wired it to work with a liquid level sensor in my water tank and i don't know what he did. (Cant get hold of him now).

The pump has a pressure switch which I am assuming is redundant when the liquid level sensor is used. I would imagine that like any switch the sensor would just break the circuit on one of the power lines. However when I do this the pump wont run, do I need to do something to the pump's pressure switch to make this work?

If I bypass the pressure switch completely the pump wont run. I can post pics if required.

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Edited January 20, 2013 by TexasRanger

[TexasRanger]

I was just thinking, do I need to short out the pumps pressure switch maybe?

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[Crossy]

Yes, photos would be useful.

A like for like replacement should just work if you've wired it exactly as the previous unit was connected.

Does the pump as supplied run if you don't connect via the level switch (just connected direct to the supply)?

Assuming the pump runs when connected direct I would expect it to work anyway, but since it's not you would need to short the pressure sensor on the pump.

I'm assuming there is no ball valve or similar in the tank and the pump should be controlled only by the level sensor.

[TexasRanger]

Hi, thanks for the help, I dont know if pics of the whole thing will help as it is hard to follow when looking at it in real life. He has used the supply to power a second pump which works fine. The new pump does work if connected straight to power. I have it working now but only on the pressure switch.

I am sure the issue is here because on closer inpection, the pressure switch silver contacts on the old pump look like they have been reversed so they don't make contact with the brass spring loaded contact. This is different to the new pump so the electrician must have done this. The confusing thing is I can understand doing that to take the pressure switch out of service but there is no continuity between the 2 wires coming out from the pressure switch, I would have thought it would be the other way round and be a short across the pressure switch so that power is applied constantly unless the cct is broken by the level sensor, am I seriously confused?

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[Crossy]

You're confused? So am I now

I have no idea why the pressure switch on the old pump has been 'adjusted' as it has, unless it was actually busted (I see it has only one wire connected).

I suggest you trace and draw the circuit from the mains, via the level switch to the pump connections.

Do note that level sensors (we have one) have a LOT of hysteresis, our tank needs to be nearly half empty before the pump starts and it only stops when the tank is brimming. Could just be that your level switch is never actually making the circuit. Ours is the floating type, so we can test simply by lifting it out of the water and letting it hang by the cable.

[TexasRanger]

Yeah, i know what you mean. Our level sensor has a shorting switch fitted also so I can run the pump when the tank is full, for garden watering etc.

The one wire is only because the other one got taken out by me when I removed the pump.

I am thinking that whatever happens I just need to short the pressure switch to get this to work.

The current setup is as below (not showing the level sensor), i guess if I just short the pressure switch and use the level sensor to make/break the circuit instead that should work, no?

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[TexasRanger]

Something like this?

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[TexasRanger]

OK after much buggering about, a bit of sunburn and plenty of foul language I think it is fixed. I wired it as per the last diagram and it is OK. The link I put in worked but god only knows what the electrician did as there is no visible link in the old pump. I think I will disect the old one now because it had me so confused.

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[Crossy]

Glad you got it going, it's not rocket science but some of the things the locals do just defy logic.