Extend contact closure from one site to another


@Bhaskar do we have a 1 channel relay board with Electron socket that has the 2 amp power supply on board? Seems like we designed that board maybe for Jordan if memory serves me correctly?


I’m inclined to go this route, Travis; I like it much better than WiFi. But I have to verify that we can get some king of AT&T cell service. I’m going to try and find someone in our community that has an AT&T phone and see if I can get at least one bar. AT&T’s coverage map suggests that they do have service on the north side of our little mountain, but I know for sure - and they map confirms - that there is no service on the south side where my house is. The good news (maybe) is that both the well and the tank sites are on the north sides!

Once I confirm that signal is available, do the contents of the cart that you linked me to earlier still comprise the entire solution at $295?


this one has 2A supply



The board Bhaskar linked above is similar to the boards I recommended but it has 2 relays and 6 inputs. This board has a higher current power supply on board to power the Electron module. The reason I bring this to light is if you go with the 1 channel relay board I recommended above then you will need to connect the Particle included LiPo battery to the Electron so it has the juice to make cellular transmissions. If you do not want to fuss with that LiPo battery then you can go with the 2 channel board Bhaskar linked above. Personally if you have the budget for it I’d recommend going with that 2 channel board but it is strictly up to you.


Since the price differential is negligible and since you recommend the 2-channel board, that’s what we’ll do.


Hi again Travis.

Can you pint me to some kind of wiring diagram that’ll help our well contractor figure out what’ll be involved in hoking this solution up to each end of the link? Also, can you verify that the shopping cart includes everything we’ll need?


Hi @blshaw45

This is a wiring diagram for a 2 channel Photon relay board. You have a 2 change IOT socket relay board, however the screw terminal layout is identical, your IOT interface board will just be a little longer.

I am not able to view your cart. Can you send over a screen shot of what is in the cart?


I believe you put stuff in the cart yourself way back in time. Here’s the link: https://store.ncd.io/cart/?kc=6fr4

I think the contents reflect the original expectation that the link would be via WiFi, not cellular.

Regarding the diagram: it appears that the SPDT relay ports would connect to the 240-volt relay at the pump end. Where would the float valve contact closure leads at the storage tank connect, one of the I/O connectors? If so, what associates a particular I/O connector to a particular relay port?

Sorry to be so dumb…


I believe you have since decided to go with the 2 relay board since it has a higher amperage power supply and a Cellular module correct? If that is the case then the cart would need to be revised. Let me know if that’s the case and I can put you together a new cart.


You are correct, Travis. Will the Electron gizmos be reflected?



We do not carry the Electron modules so you’ll actually have to purchase those directly from https://store.particle.io

Here is an updated cart with everything you need from us for this application:

Keep in mind you will need to purchase two electron modules from Particle for this project.


Hey Guys, I wanted to mention a couple of things that I like to do in remote pumping situations:

Well Site:
If the well panel doesn’t already have an HOA switch (Hand-Off-Automatic), you might consider having your well contractor adding one. This allows you to quickly and easily remove the Cellular Control when working at the Well Site. It also allows you to easily start the Well locally during a Communications failure, etc.

Another future option is adding a pressure transducer (gauge) to the Electron at the Well Site. This can be used as secondary Control Logic in addition to the Publish/Subscribe Method from the Tank Site’s Float Sensor.
The Pressure gauge can easily approximate the Tank Level from the Well Site. In the event of a Communications failure, the Well Site Electron will start the Well when line pressure drops too low and sends an Alert, as a fail-safe.

Tank Site:
The same type of pressure transducer can be used to replace the Float Switch at the Tank, or as a redundant sensor. Doing so will also allow you to always know you tank level from anywhere in the world in real time, verses the Float Switch.

You can add the pressure gauges (and modify the Code) in the future if you want. It’s a cheap method for redundancy at both Sites and adds a lot of value in my opinion. The Pressure gauges will pay for their-self the first time they prevent the Tank from Draining (thus preventing a Service Call-Out).


Agreed on all points. Its better to know the actual level of the tank and not just whether it’s full or not. The hand off switch is great as well and will be used at some point.


Hi again Travis.

My apologies for disappearing for a while. As I suspect you know, when dealing with a freakin’ committee, nothing moves quickly or, may times, logically. There is one clown involved in the decision making here that thought it best to try and locate and repair the wire between sites. So an electrician was called in and he pointed out that it is difficult to buy a reel of wire that is long enough to span the entire 1000’ (+/-) distance so there is likely an underground splice that is the cause of the loss of continuity. Running a new wire would result in the same problem again in the future, so he, too, recommends the cellular solution. $400 fee for that advice! That would have paid most, if not all, of the solution that you and others here have recommended. So we’re almost ready to pull the trigger, but I have a couple of remaining questions:

I will need an Electron at each end, right? $69 each plus $2.99/month each for AT&T IoT service, if I read the description on Particle’s website correctly.

The well company has no idea how to wire anything other than AC power to the pump, so they always call in an electrician for anything electronic. Is it possible that you, Ryan or someone else here on the forum might be willing to draw a simple diagram that shows connectivity to the float switch on one end and the pump circuit/relay on the other?


Have the electrician reference this diagram:

At the Tank side the two contact wires from the float switch will connect to GP2 and one of the GND terminals

At the Well side the contact lines that operate the pump will connect to Relay 1 NO and COM.

When the float switch opens there will be continuity between Relay 1 NO and COM terminals. When the float switch closes continuity between Relay 1 NO and COM will drop.

If you or he have any questions on this please let me know.

Thank you,
Travis Elliott


G’Day Travis,

We have ordered the devices you have recommended (order placed by our treasurer, Kevin Huck) and we have already received the Particle Electron devices. With the latter, we have verified that we have solid cellular connectivity at both the well site and the tank site. We are excited to receive the NCD equipment and get the solution up and working. Thanks for all your advice and counsel offered on this forum.

I do, however, have a couple of additional questions:

As recommended, we ordered the 10-amp version of your device, but the pump draws more than 10 amps (it has a 20 amp, 240 volt circuit breaker). Is the solution to provide an external relay with a control current that is well below 10 amps? Maybe a simple 12 volt DC input unit like this: https://smile.amazon.com/Ogrmar-SSR-25-3-32V-24-380V-Solid/dp/B074FT4VXB/ref=sr_1_8?ie=UTF8&qid=1540352587&sr=8-8&keywords=240v+relay? Really cheap.

Before we hook everything up permanently, can we test it by connecting a 12-volt DC device of some type - maybe an LED lamp - to the relay output at the well site?

Many thanks again!



Brian, the NCD board should operate the same starter or contactor that your previous underground wire controlled. You wont be switching the 240V Water Well directly with the NCD board.
The Cellular link just replaces the underground wire.

I believe the suggestion was made to use the 2-channel relay board simply because it has a larger (2 Amp) DC Power Supply. That allows you to Remove the Li-Po Battery from the Electron. No Li-Po makes life easier if the Electron lives in Freezing Conditions, etc.


Thanks Ryan. I think I may finally be getting my arms around this stuff!


Oops. Just looked at the order. Yes, it has a 2-channel board, but the power supply is described as 1.5 amp. Problem?


Hi Brian,

1.5 amps is the power supply on the board that powers the communication module(Electron in this case). The relays on the board are rated for 10 amps. Ryan is spot on with his recommendation to use the relays on our board to control the contractor that is already undoubtably in place.

I have your order here at my desk. I think the simplest thing will be to ship the boards to you and then walk you through flashing the firmware onto the electron modules. I will get the boards shipped out today. Please leave a message here as soon as you receive the boards and I will get you instructions and a link to flash the firmware onto your Electron modules.

Thank you Brian,
Travis Elliott