I'm gonna do as much searching as I can, but I have a homeowner (I've worked for forever). Keeps having problems with his well/water system. This year he has put over 5k into it and the well guys still can't get it right. And its the second set of well guys. I told him to get rid of the first guys cause he didn't know what he was doing. The well pumps to a reservoir and therefore is controlled by a float switch. The controller for the float switch is the issue. The first guy I had to argue with because he kept saying there was a short in the float wires because it read 220. If there was a short it would read 0 because there would be no difference in voltage. So the float switch lead that has the power where it shouldn't goes back to the coil on the contactor, which is what kicks the pump on/off. So this tells me the contactor needs to be replaced, that it is shorting to the coil somehow. But the coil test in range on ohm reading and it has already been replaced 2 or 3 times (at $600 a pop) by the other guys. So something may be wrong with it now, but something is causing it to continually go out. All the other relays and capacitors test within spec. If anybody has any ideas I can post a schematic
Help!! electricians, well guys, anybody
- Thread starter tbrooks
- Start date
In bigger tanks and Res's, level control is usually controlled digitally with 4-20mAcontrol circuits.
I have done some work on some small er stuff like your talking about, there should be a set of contacts that are open when float is full, closed when it is calling the pump. They sometimes arc them self together, or the wiper mechanism will just get froze up.
See if you have a set that is coming from float switch to the pump... I'd imagine that's where the problem lies. You can get them from Grainger if you can find the parts # on them.
I have done some work on some small er stuff like your talking about, there should be a set of contacts that are open when float is full, closed when it is calling the pump. They sometimes arc them self together, or the wiper mechanism will just get froze up.
See if you have a set that is coming from float switch to the pump... I'd imagine that's where the problem lies. You can get them from Grainger if you can find the parts # on them.
Its got a Franklin control box, and a simple float switch. The box has the contactor, 3 capacitors, and a couple relays. The float completes a circuit to activate the coil, which activates the contactor to turn the pump on. I found an article by them saying when the control mechanism (float) is more than 300 feet away you should put a capacitor on the leads to the coil of the contactor. Otherwise the wires over that long of a distance create their own electricity, to put it simply. I know they are around 1000 feet apart so I would assume that is the problem.
I don't know what size capacitor you'd need...a lot of that comes from info on the motor itself power factors and and other things. Might be worth looking into if there is a soft start that's available for it.
What voltage is being applied to the control leads.
AC or DC?
What is the wire size of the leads, are they fig 8, or spiral wound, and what type of dielectric.
Is the problem actually caused by mutual induction, or is the long lead restricting the current flow?
AC or DC?
What is the wire size of the leads, are they fig 8, or spiral wound, and what type of dielectric.
Is the problem actually caused by mutual induction, or is the long lead restricting the current flow?
only thing i know or think i know about capacitors is,i believe it is used to store power,so if it gets a big voltage requirment all at once it can take from the stored energy in capacitor,and not tottally from electrical supply,but that is winging it ,not positive,lol
I confirmed with the homeowner earlier theres 1600 feet of wire, pump to float switch. The wire is UF 12-3, which is not built for long distance at all. 12 awg solid copper with no shielding. It carries 120v, up the black and back down the white with a red and ground in between. The problem is when you have very long wires, so close together it kinda gains capcatince, possibly mutual induction as blaaster said, but I have forgotten most of my electrical knowledge from school. I know it creates extra power(?) and keeps the switch open when it should be closing or something like that lol, and it could also be frying the coil because of the extra voltage generated. A capacitor will take the extra power and discharge it, is what I assume. They told me (the controller switch company) to use a 5 or 10 microfarad ~240v capacitor on the coil leads (yel and blk). Its not gonna be taking the load of the motor, just flipping the contactor to complete the pump circuit.
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I too feel that the mutual inductance could be providing a ground over such a long distance.
The voltage loss over such a long run could also be a factor!
The voltage loss over such a long run could also be a factor!
Here look at this http://www.franklin-electric.com/media/documents/vol16no2.pdf Now according to this, this would keep the pump from shutting off, which seems to be how the problem starts. Now there could be a problem in the wiring that I can not pick up because of my small tester. The tech I spoke with said I/we would need to get someone with a "megar" (not sure of spelling) to accurately test that long of a run. We are running another line up to the reservoir from the HO house which is about 300 feet. This is so we will have power there, mainly to clean the tank with. I suggested to him that we might be able to use that to deliver power to the float switch. I'm not sure if that will work because in the circuit diagram the power entering each side of the coil is out of phase with the other. I will be calling franklin elec back on Monday to find out more about the capacitor I need and see if my alternate power source would help anything
Well I've got it all up and running. I was slightly confused from working with the well guys and it is actually a 240v coil which activates the contactor. Also I misspoke above, the capacitance created in the long cable lead was keeping the contactor CLOSED, so therefore the pump would just keep running. So I can't use the alternate power source as I thought, or rather I could but it would have to be the right phase, but its all working so it doesn't matter. Got the capacitor installed as directed across the contactor coil and replaced the contactor, because the one the previous guy put in was actually for hvac and could not handle the start amps of the motor and therefore burnt up. Glad to say the HO is elated, but I informed him that I can not guarantee how long it will last. Hopefully it is all good now and will last awhile. His current well guy was dumbfounded that I (not a well guy) was able to get it working after he has tried for months, and he's prob mad that he didn't get to sell him a $4000 wireless float system he was trying to talk him into
Congratulations on the fix!
What one will have learned from this lesson is that if you run electrical conductors in close proximity and parallel for some distance, mutual inductance will occur and wreak havoc.
What one will have learned from this lesson is that if you run electrical conductors in close proximity and parallel for some distance, mutual inductance will occur and wreak havoc.
