# Measuring variables from a Portable Power Generator.

Hello dear Friends,
I´m a brand new member of this forum and I really don´t know how to start....so please excuse me if I'm doing something wrong.

I'm currently working on my thesis project and there are some issues I need help with.
The project is about measuring many variables from a portable power generator. This variables are Power, Energy, Current, Voltage and many more. But.....we want to measure these without manipulating the internal circuitry of the generator + I know the current & voltage will not be suitable for a direct interface with the arduino....How can I do this? Any good ideas?

Also, the main purpose of the project is to estimate the amount of fuel needed for a certain time of active work. I know I ought to measure the efficiency of the Generator based on the amount of KWh per Liters/Gallons of fuel. Does someone have an idea on how to make this test in a easy and accurate way?

Peace. 8)

I presume it is an AC generator?

You can get clamp-on current sensors that an Arduino can read. I think for voltage you will need a suitable transformer to bring the voltage down to a max of +/- 5v and then a rectifier to get rid of the negative part.

I am interested in the results - what sort of generator are you using?

...R

If you can't access the internal circuitry of the generator, you will need a clamp-on current transformer for each device connected to the generator. And you will need to clamp onto ONE power lead, not the whole cable. So, how many devices are going to be taking power from the generator?

Paul

Here is how to safely measure AC mains voltage and current with Arduino.

Robin2:
I presume it is an AC generator?

You can get clamp-on current sensors that an Arduino can read. I think for voltage you will need a suitable transformer to bring the voltage down to a max of +/- 5v and then a rectifier to get rid of the negative part.

I am interested in the results - what sort of generator are you using?

...R

Hello Mr.Robin.

You are right! I'm using a generator similar to the Honda EM4000S. I have been thinking about using those clamp-on current sensors....but I have some doubts you might help me clarify.

As you know, generators have usually several outlets. Let's assume my generator has 7 outlets and I have 3 Loads connected respectively. That means that 4 outlets are void and not consuming current at all. So, is there any way to measure the TOTAL current coming from the outlets,without altering the internal circuitry and without using 7 separate Clamp-On current sensors? BTW, If you were to do this measurement what kind of clamp-on sensor model would you use?
Thanks

Paul_KD7HB:
If you can't access the internal circuitry of the generator, you will need a clamp-on current transformer for each device connected to the generator. And you will need to clamp onto ONE power lead, not the whole cable. So, how many devices are going to be taking power from the generator?

Paul

Hello Mr.Paul

I know you ought to use a single clamp-on current transformer for each device connected to the generator to know the amount of current each load is demanding....but is there any other way to measure the TOTAL current coming from the outlets,without using a separate Clamp-On current sensor each time? Can I make myself a current meter out of existing current meter modules, such as the ACS712 Module for Arduino, a multi input current meter? If it's possible can you give me a hand with the diagram?
I guess the Arduino sketch would include a summation of all the currents....right?
Thanks. ;D

On generators I have had in the past, I have had to operate them monthly or so, just to be sure they would work in an emergency. I have used several electric heaters to provide the load. If you did the same, you could get pretty close to the total power usage by adding the rated power of each electric heater.

And the ACS712 modules I saw would probably work for you, but in any case you will need access to the electric wires going to each outlet.

On another piece of information. The generator most likely is a center tapped unit, supplying 240 volts and a grounded center tap. Each set of 120 volt outlets is tied to one end of the 240 volt output and ground. So you load should be balanced for each side of the generator power output. I am sure you know this. It's in the instruction manual.

Paul

I was hoping it might have been a Honda EU2000i or similar

If you are using electric heaters to dump the power please don't have them close to the cans of petrol. When I was working I was taken to a demo where that was being done. We asked them to move the petrol cans

...R

Robin2:
I was hoping it might have been a Honda EU2000i or similar

If you are using electric heaters to dump the power please don't have them close to the cans of petrol. When I was working I was taken to a demo where that was being done. We asked them to move the petrol cans

...R

We use this power generator on the mission trips in order to provide enough power for dental compressors set on the clinics. We're always careful with the petrol cans

jarib777:
We use this power generator on the mission trips in order to provide enough power for dental compressors set on the clinics. We’re always careful with the petrol cans

Ok. This sounds like a permanent problem and may be for more than one generator. If this was my project I would:

Build a box similar in size to the output panel of the generator. Mount the same number of power outlets on one side of the box so the compressor, etc. can be plugged in.

One the opposite side, I would have short power cords coming out to connect to the generator sockets. One for one.

Inside the box, I would separate the wires in the short power cords. Ground the green wire to the box so the generator and box are at the same potential.

I would get one of the ACS712 modules for each power cord and wire it in as the instructions say.

I would select ONE short power cord to always be plugged into the generator. To this power cord, inside the box, I would connect a power supply for the ACS712 modules and your Arduino and what ever else you need.

Then you can test all this without actually having the generator hooked up. Your regular power can go to the special power cord.

There is no way you can get what you want on the cheap!

Paul

You can buy "monitored PDUs" (power distribution units) like those that are used in datacenters. The problem is that they start around \$250 for a 15A max unit with ~8 outlets, but you can find models with a serial port or ethernet (web) interface.

If you want to build it yourself then you should look at chips like the MCP3901 or Si8900.