Author Topic: MY PERSONAL HOME HMI  (Read 345 times)

DavidSr

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MY PERSONAL HOME HMI
« on: April 05, 2025, 01:58:58 PM »
My guess is that most of you will look at this and see what appears to you as a disorganized mess with too much on one screen. This it what happens when you slowly build and add on to a project over time.
It certainly can use some re-arranging which I am slowly working on but my HMI screen is a 27" monitor so I can get a lot on one screen and I actually prefer having everything visible as opposed to having to click on a control to bring up another screen. I will be upgrading the monitor to 34" so that will allow me to spread things out and group them better.
I have been working on this slowly as a hobby for several years. I just started adding the generator section which monitors our Kohler 26KW generator. It will actually get it's own HMI at some point but be using the same PLC in it's own file. So far I have 25 separate ladder files in the PLC.

Anyway.. this serves our purpose for many things including monitoring our propane usage and percent left as well as predicting when we will need to get a re-fill. Beats walking out to the propane tank in nasty weather.
« Last Edit: April 05, 2025, 02:29:57 PM by DavidSr »
David

boardmaker

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Re: MY PERSONAL HOME HMI
« Reply #1 on: April 10, 2025, 02:18:46 PM »
Really cool David!

Could you explain a bit more about how you monitor your propane?
What size tank?  What sensor(s) you use?


DavidSr

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Re: MY PERSONAL HOME HMI
« Reply #2 on: April 10, 2025, 08:40:13 PM »
 
Really cool David!
 
 Could you explain a bit more about how you monitor your propane?
 What size tank?  What sensor(s) you use?
 
The tank is an older 450 gallon and unfortunately the gauge cannot be retrofitted with any type of electronic device to transmit the level of the propane inside without completely emptying the tank and changing the level indicator socket and float. If the propane supplier had provided a different tank this would have been a lot easier.
 In order to know how much propane was left at anytime without the luxury of a meter or the availability of sensors which I would have preferred, I came up with a way to monitor the usage of every gas appliance we have and use that to determine how much fuel was left. The only sensors involved are discreet Inputs to my PLC monitoring the gas valves on every appliance being monitored.
 This is how I did it
 Establish some constants and multiply them by variables.  Each appliance has an input BTU rating on its nameplate.  1 Gallon of propane is 91,452 BTU.
Starting with whatever percentage of fuel is in the tank, you calculate the amount of fuel to reduce it by Multiplying the time your appliance gas valve is open x the input BTU of the the appliance. 

 
For example: If a  80,000 btu per hr furnace gas valve is open for 7.5 hours in a week, the fuel it used is:(80,0000 X 7.5)  / 91,452  or  7.5 x 80000 / 600,000  / 91,452= 6.560818790185015  Gallons for the week. Of course to have a constant update every cycle an appliance runs, we multiply the time the gas valve is open for each cycle.

 
The fuel used for all appliances combined is totaled each time a gas valve closes in every appliance.

 
The math gets a wee bit more complicated that way since we are multiplying by seconds the valves are open not hours. 

 
This has proven to be surprisingly accurate. We only have to make adjustments a couple times a year. When it was first set up we did watch and tweak the input BTU values of the appliances to get a more accurate value then what is on the nameplate Adding all appliances usage every time an appliance gas valve shuts off gives a constant real time amount of propane left in the tank. In addition all values are moved to a memory location for each appliance at midnight and used to calculate daily averages weekly averages and monthly averages PER DAY. This data is kept for 6 months before being overwritten. This way we can also project how much fuel we will need to buy the next season.  The projection of days to 20% or 60 Gallons is based on the average gallons used per week. -

 
As a side note, I have been involved in discussions with electricians and other engineers about how to compare the cost of heating a building, a house etc.  with one method of heating vs another and quite frankly I am surprised at the ignorance of people that have more formal education than I have.So for anyone that cares to know, To compare your heating cost with your neighbor based on the heating source used You MUST as in any math equation reduce the formula to a common unit. In this case BTUs. Determine from the bill how many BTUs were used to heat each home based on the heat type used so many BTUs per cubic ft of NG, so many BTUs, Gal LP GAS, So many BTUs per Kilowatt of electricity.Then the cost per BTU from the supplier of the source. I can tell you from years of study it is NEVER less expensive to heat with electricity, The cost per BTU for electricity has historically been much higher then the cost per BTU of all other fuels.You have to know how many BTUs are in the source being sold in order to compare.

 
« Last Edit: April 11, 2025, 08:40:25 AM by DavidSr »
David

bachphi

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Re: MY PERSONAL HOME HMI
« Reply #3 on: April 11, 2025, 04:02:59 PM »
This easy-to-use sensor requires no installation and uses ultrasonic technology to accurately measure propane levels.

https://www.walmart.com/ip/Mopeka-024-2002-Tank-Pro-Sensor-with-Magnets-for-Steel-LP-Tanks/902607225?classType=REGULAR
UCL =================
This is NOT alt.read.my.mind.
No such thing is sh^t-for-brains unless you are posting to alt.read.my.mind.
My understanding of computer is well below six Σ. Savvy?
Unless what I say is logically defined in a PLC, everything else might be beyond my control.
LCL =================

DavidSr

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Re: MY PERSONAL HOME HMI
« Reply #4 on: April 11, 2025, 05:58:33 PM »
 

 This easy-to-use sensor requires no installation and uses ultrasonic technology to accurately measure propane levels.
 
 https://www.walmart.com/ip/Mopeka-024-2002-Tank-Pro-Sensor-with-Magnets-for-Steel-LP-Tanks/902607225?classType=REGULAR


 
Not so accurate.. but I appreciate the response bachphi

 
I looked into these a while back, They were not available when I built my own system.

 
Actually my system is more accurate because these do not work well and are not marketed for use on large tanks. Accuracy depends on the tank being pretty well level and no way to easily input the results to anything but its own reader. If this is the technology a person wants to use, there are better options that don’t incorporate dedicated readers. Like https://maxbotix.com/products/mb7854-tanksensor   with stand alone devices you can connect the output directly into an analog input module of your PLC.

 
I looked into other sonic devices and find them excellent options for measuring distances which is actually all they do. I have tested them to measure the salt level in a brine tank, distance to a vehicle entering a garage to signal the driver when to stop,  distance to a vehicle in front or behind you and tons of other applications but measuring the liquid in a large tank would not be my choice.

 
Also it is nice to have a system that is as accurate as mine with no sensors to maintain . :-)
« Last Edit: April 11, 2025, 06:08:57 PM by DavidSr »
David