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Long story... Might have been last fall but I posted about wireless well to tank water control for a 40 home subdivision. We put in whole home plus power strip surge suppression on the power plus gas discharge surge supression on the RF antenna. Good single point grounding.
We are at 7000 ft el and the tank on hill gets more than its share of lightning and about three weeks ago, lightning burned out the wireless electronics. The power to the electronics was fine, the inputs and outputs were fine, I think the antenna RF input on the hill transmitter was burned out.
For nearly 40 years before this, the well/ tank control was a buried wire. The wire has some corrosion problem that caused the system last fall to keep the pump running all the time so when the wireless burned out, I (volunteer retired EE) modified part of the wired system and its working right now but expect the wire to further degrade. Ie, I just bought us some time for a more permanent solution.
We are going to put in another wireless system but we are also going to fix the buried wire so we will basically have two completely different methods for the water control comunication. At this point, Im liking the wire better as its only mechanical switches and relays at the tank on the hill and no antenna inputs. Ie, the wire system is very robust for lightning.
The problem with the wire is that for years, the control used about 1/2 miles of phone line wiring and somewhere in that length is where the corrosion is that is causing the problem. We want to get away from the phone line wiring. Years ago, a resident left about 3000 ft of suitable to be buried never used wire and we are thinking about bypassing the funky phone like length with the wire we have.
The signal on the wire will be 30 VAC and current limited to about 0.15 amps. I believe this qualifies as low voltage and only needs to be buried 6 inches https://www.electricteam.com/blog/20...0above%20grade This site just mentions 30 volts, no mention of AC or DC.
The wire run will go along a county maintained DIRT road with utility easements on each side. Utility easements are on property owners lots sometimes crossing driveways. The easements already have buried electricity, phone, natural gas and fiber optic lines. Plus the wire would need to cross the dirt county road at least one time.
We have not talked to the county about this yet. The residents like having water to their homes so no issue using the easement. We would need to find out where all buried cables were and I think this qualifies as low voltage. Its rural and the residents have tractors etc so putting the wire in might be a mostly volunteer job.
Yep, I know we need ot consults experts and the county. But any comments. Are we crazy to even think about running this 1/2 mile long wire along a dirt road? All in an HOA, we are on the HOA water board. As a home owner here, the buried wire is the only solution that Im going to really trust given the lightning history of the hill where the tank control is.
What exactly are you/were you controlling with the wireless?
How far is the well/pump from the road that has the utilities/easement?
I think you may have a solution with the fiber-optic...
I don't think your solution would fly with the AHJ. The easement is for those utilities- not HOA private property (which is basically what your "wire" would be. And "low voltage" can sometimes be rather confusing even within the NEC, the term “low voltage” can mean anything from less than 600V, 50V or less, or less than 30V depending on the section you reference- note there is no refrence to AC or DC.
The well and tank are 0.7 mile line of sight apart.
Well house is pretty much on the easement that goes along the dirt road. The wire goes from the well house (pump) along the road and quickly picks up the phone line wiring at the frist home owner lot (and first available phone line stand). At the end of the road where the last phone line stand is and where the fiber optic ends, a good wire about a 1/3 of a mile length runs up to the tank on the hill. So one issue with the fiber optic is that it doesn't go up the tank on the hill and never will (super expensive to even think about). I suppose some fiber option solution that still used that last 1/3 mile wre up the hill might work but this would be complicated including powering things.
How it works.. We have AC power up to the tank on the hill. There is a float in the tank that basically closes a switch when the float goes to the low level. When the float indicates low, a signal either on the wire or wireless goes to the well house and tells the pump to run. After some hours, the water level in the tank causes the tank float to go to the high level and the mechanical float switch turns off. That signal then turns the well pump off. This will all vary from system to system and depending on time of year (winter time the pump runs much less) but the pump will run from 6 to maybe 9 hours, then be off for maybe maybe 12 to 16 hours. Water use is the highest per year right now (very dry, waiting for the monsoon) and the pump is runing somewhere between 1/3 to nearly half the time. In the winter, the pump runs about 1/5 of the time.
With the wireless, the float switch just activates a dry contact input on the transmitter and the receiver at the well just closes a relay output that goes to the motor start up. The wired sytem just modifies the 30 VAC ac signal and that is easily detected at the well house.
I think the wireless solution we picked last year is NOT well designed for lightning and I think there are better solutions. We are also considering cell based control.
If you want to hear my crazy theory.. I will post it but I think the higher frequency wireless systems (ike cell or 900Mhz) may be more tolerant of lightning and we will implement every possible surge protection option possible but.. man Im still a little worried and it really s_cks when the control burns out. I think Zeus spends the summer on this hill
Last edited by waltcolorado; 07-20-2023 at 09:24 AM..
I remember your posts. I'm a little surprised the electronics got fried, but I guess they are more delicate these days.
With all the problems on the hilltop with electronics, your ultimate solution might be to eliminate them entirely.
You obviously already have a buried pipe going from the pump to the cistern. A second smaller overflow pipe, buried alongside, would allow water from the cistern to overflow into it and back to the pump house. When water in that pipe had enough pressure, it could flip a cut-off relay at the pump house. a drain hole back into the well would then purge that line of water. After an interval of four hours, the pump would cycle back on again and run until the overflow again shut it off. That eliminates all electronics on the hill, eliminates excess wiring and makes it simple.
The downside is the need to dig up the original pipe to lay the second one. However, if the first pipe is either too small or old, replacement could be done at the same time.
If the water line is in good condition(no leaks) you could put a small (2 1/2 gal) captive air tank and pressure switch at the pump and install a solonid valve at the tank controlled by the float switch.
While the tank is low the float opens the solenoid valve allowing water to flow, the line pressure drops and the pressure switch starts the pump. When the tank fills, the float closes the solenoid and the pump brings the line pressure up to the pressure switch cut off point and the pump stops.
This method counts on the piping not having any leaks, if it leaks the pump will short cycle it's self to death in a short time. As insurance you could put a timer at the pump that will not allow a restart inless the pump has been off for 1/2 hr or more
If the water line is in good condition(no leaks) you could put a small (2 1/2 gal) captive air tank and pressure switch at the pump and install a solonid valve at the tank controlled by the float switch.
While the tank is low the float opens the solenoid valve allowing water to flow, the line pressure drops and the pressure switch starts the pump. When the tank fills, the float closes the solenoid and the pump brings the line pressure up to the pressure switch cut off point and the pump stops.
This method counts on the piping not having any leaks, if it leaks the pump will short cycle it's self to death in a short time. As insurance you could put a timer at the pump that will not allow a restart inless the pump has been off for 1/2 hr or more
I like this idea-
But, 3/4mi of pipe leaves a lot of "what if's"...
I dont think we will mess with the pipe going up the hill (at least I wont, not something I know anything about). With our temps here at 7000 ft el, water pipes are also buried under at least 5 ft of dirt.
My partner (two us handle the technical well stuff) did run some numbers of just looking at the pressure. This is already a pressure gauge in the pump house, it runs 100 to 105 psi (when the pump is running) but the pressure difference between the tank not needing water and wanting water is not significant enough to reliably resolve.
The subdivision has wireless meter reads on all the homes which are read once per month. Last fall we added an additional read of the main water meter (which will also be wireless within a month). We then take the sum of all the homes and compare it to what the pump put out. The difference is a leak somewhere in the distribution. We do have some leak in the distribution but that has so far been in the noise compared to some other issues. The well has been run by the HOA and typically NOTHING gets done each year and a large turn over of the folks who are involved. Not at all a fan of an HOA run well...
Harry, I think the product we picked was a poor choice made in an emergency situation and had poor RF input protection. We could not even find a manual for this product. The RF input at least has to survive surge voltage until whatever antenna surge suppressor kicks in. Some chance we just made a bad choice.
Below is what I sent to a few folks regarding why I think higher frequency for the control hardware may be better for lightning and at the moment, am thinking our replacement wireless will be cell or 900 Mhz. The wire is backup and I want both the wireless and backup wire in place (after dealing with two emergencies now.. not at all fun).
----------------
(note, the system we had burn out was 433Mhz and used a fairly large Yagi antenna)
Lower frequency tends to use longer antennas, higher frequency shorter antennas. Example, RCT Legacy 27mhz antenna is 42 inch. HS 154Mhz antenna is 39 inch. RCT newer 900Mhz antenna is 23.6 inch (I believe the actual antenna is even shorter than this).
Conclusion from looking at these two papers.. The 900 Mhz RCT or the cell based applications should be better for lightning. The lightning spectrum is mainly under 300 Mhz and these systems use shorter antennas so should couple in less energy. This is just my observation, could be wrong, I dont think you will find this referenced anywhere.
All of the products should have some sort of surge protection on the RF input, typically a PIN diode, then a filter based on the operating frequency.
FYI, all of the wireless meter reads are some sort of 900 Mhz system. The antenna is on the cover above the home meter pit. As far as I know, lightning has never damaged any of these.
Last edited by waltcolorado; 07-20-2023 at 11:56 AM..
Use a fiber-optic cable, and run it INSIDE the water line!!
Fiber-optic is immune to corrosion/saturation; simply empty the water line, and blow a pull-cord (braided nylon line) thru the drained pipe using compressed air, then use that to pull the fiber-optic cable thru the pipe.
I'd use 'positive' signaling (turn pump ON when light sent thru cable - OFF when no signal) - safeguards burning-out pump by overrunning.
Somewhat technical post that a few folks here might find interesting and your discussion was useful to me.
Back story, we have a community well for about 40 homes where the well/ pump is about 3/4 mile from a tank on the hill. The tank has a float switch that uses some sort of communication to turn the well pump on and off. Water pressure to the homes is provided by the tank being on a hill higher than the homes.
Originally this communication was a wire (actually used a wire out of the old style phone company buried bundle) and that wire went bad. Not totally bad but it changed enough to where the old system kept the pump running constantly.
Last fall, we installed a 433 Mhz wireless system including antenna surge suppression and whole house AC surge suppression and the first big lightning storm this last spring blew up the wireless system.
I temporarily got the old wire (using about 1/2 mile of the phone companies wire) working with a custom electronic circuit and that ran the well most of the summer while we worked on a permanent solution.
Late this summer, we installed a new wireless system (different manufacture - Hotshot 154 Mhz) also with good antenna surge suppression (Polyphaser) and with good AC power surge suppression.
First twist in the story is that I took apart the old damaged wireless system to see what had blown. Turns out it was at the well house where the wireless receiver has a relay output that provide a power signal to run the pump. Lightning charge from the well control electrics had jumped across the relay contacts on the wireless receiver to the relay coil and blew out a bunch of stuff on the circuit board.
So our failure was actually caused by poor grounding. We had done a good job grounding the new wireless receiver box but it turns out the rest of the well electric stuff might have had adequate grounding at one time but after 40 or so years, was no longer adequate. There is a high voltage power line close to the pump and I think somehow lightning charge went through the AC power lines and created a large ground difference between the wireless box and the well electrics.
So now the well electrical box has a good ground to the common ground connection that the wireless box is grounded to. The intention is to keep the wireless box and the well electrical stuff near the same voltage potential in a strike. I also added MOV surge suppression from the relay contacts to ground that should limit surge voltage from getting high enough to jump from the relay contacts to the circuit board. Our next lightning season wont be until next summer.. Lesson learned.. you have to have a good "star" ground on all the equipment that is tied together.
The second twist to the story.. Turns out the subdivision had been using about 1/2 mile of the phone company wiring for many years without paying for it. I dont know the story about how this happened but about a week after we got the new wireless system working again, the phone company used OUR wire to service a new house that someone built and wanted a old system phone.
What fortunate timing we had to get the new wireless control setup just barely before the phone company took their wire back. Fortunately for us, they waited about 40 years LOL We have no backup wire system now so have to make this new wireless system work.
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