Where can I tap in a diesel generator

Alright. Had a long day at work and couldn’t respond sooner.

As I have stated before to get started you need a RPi3, and RS485 to TCP converter as the hardware list, assuming you have the easygen 2500 panel then installing the emonCMS image onto the sdcard to establish modbus communication with node-red application the use JSON to publish to emonCMS.

Now to answer your second post, yes you can have arduino and modbus under each RPi3 your choice but the simplest way is interfacing instead of splicing into analog signals. Issue I potentially see with tapping into analog signals from the panel is the voltage drop you will encounter when connecting to a analog signal. Say your RPM gauge says 1500 RPM and you tap into that signal, you will read 1400 RPM give or take because of voltage drop, and the genset panel will read 1400rpm and will mess the signals going to the panel controller. Just giving you a heads up.

Like I stated earlier all commercial gensets have modbus available, it’s a matter of figuring out how to communicate to it. Some are easier to interface than others but it’s the correct way of doing things. I have never seen tapping into analog signals of me integrating genset systems for 6 years.

Yes the TCP converter is a cat5e you can connect to a switch, both the TCP converter and the RPI to communicate via TCP.

Your choice at this point but I highly recommend modbus, once it is setup, you will love it.

A RS232 bus is a peer-to-peer connection, only 1 master (RPi3) and 1 slave (easygen 2000 panel)

A RS485 is a multi device protocol utilizing 2-wire communication with a daisy chain communication.

You are more than welcome to buy the RS232 to TCP converter but it will cost you more than a RS232 to USB would, and you will not be able to add more RS232 devices under the RS232 to TCP converter except 1 slave device.

I think you misunderstood me.

I was asking why not RS485 to USB?

1 Like

Good question, I did misunderstand, I’m sorry. yes that would work too, I use a RS485 to USB adapter to troubleshoot modbus communications, but in the commercial space we use TCP as much as possible with its ease of use and wide acceptance.

Many possibilities, just have to figure out which one would work for you and run with it.

Not a problem. :slight_smile:

You’ve confused me with the OP though. His name is Jason.

1 Like

Ahh yes. I hit the wrong reply. I’m using my iPhone to reply. Don’t have access to my laptop.

Can you give an insight how you are integrating your watt meters using pymodbus into emoncms? Perhaps start a new topic under show case and show off your work.

Do you mean for example, a one line diagram? Or perhaps the Python code? Both?
PyModbus was overkill for the Wh meters, so I went with minimalmodbus.
Happy to help if I can. I’m an Electronics Tech, so coding insn’t my strong suit. Just want to be up front about that.

Hi. the easiest and safe way to connect to the gensets is to interface.

i just dont know if our old gensets have modbus. thats why we are considering directly tapping to the output of the gensets. can you give me some advice if ever no modbus is available. what is the safest and most accurate way to monitoring the gensets power?

I understand not all gensets in the older generation offer modbus but there is a high chance they do since modbus has been around since 1979.

If they don’t have modbus capability then the most accurate way is to use a split core type amp meters that also monitor the voltage and amps on each phase and also offer multiple modbus points such as volts per phase, Amps per phase, kW output, and more.

Here’s one set of split core power meters we use in an event where they have a older style generator and do not modbus. Refer to page 17 for the available information available from the meter. eBay has these meters for a very good price.

Yes the meter is modbus, any industrial PLC will always have Modbus, any serious Plc will have at the very least modbus If not other protocols as well.

Yes both and if you got pictures as well to share on the showcase site on this forum, how you are using emonCMS to monitor.

thank you very much. we will try to work on this and ill update you guys. i really appreciate all the things you said to me. ill try to keep in touch. :slight_smile:

guys.can you help me find some batteries. i need the price and where can they be bought. I’m trying to find batteries for my prototype.
I need a:

18650 Li-ion battery - 3500mAh,(can be higher) 5V output.
18650 battery pack - 5400mAh(can be higher) 12V output.

and a current transformer with this kind of specifications non-invasive type and is flexible for ease in installation even at tight spaces and can fit for wider range of cable diameters without drawback on its performance. It shall be capable of operating at high voltages and can read current from 0 to at least 5000A. The furnished Current Transformers/Sensors shall have its compatible cable for optimum data transmission.

The Current Transformers/Sensors shall be self-powered and shall output current in milliampere range (standard 4-20mA). All necessary protections on the part of the sensors and of the personnel shall be required

thanks guys

The term high voltage is ambiguous. Can you specify an actual voltage?

Very true. I once heard a transmission line engineer, used to working with 275 and 400 kV systems, call 11 kV “low voltage”.

@Robert.Wall and @Bill.Thomson my colleague says. the cts will work at voltages up to 480V.

so 480V is categorized as low voltage?

this is the power supply of my arduino mega.

The power supply of my Arduino Mega module board shall be able to provide regulated power of 5V and 1A, ensuring longer operating hours in case of power interruptions and emergencies; as well as to sustain the board in full operating conditions.
i want it to be at least 4 x 18650 Li-ion batteries rated at 5V and capacity of 3500mAh. Batteries shall be with battery holder and charger modules with input (charging) rated at 5V, 2A; output (discharging) rated at 5V, 1A.

this is the power supply of my RPi3.
The power supply my Raspberry Pi 3 Model B shall be able to provide regulated power of 5V and 2.5A, ensuring longer operating hours in case of power interruptions and emergencies; as well as to sustain the board in full operating conditions.
i want it to be at least 6 x 18650 Li-ion batteries rated at 5V and capacity of 3500mAh. Batteries shall be with battery holder and charger modules with input (charging) rated at 5V, 2A; output (discharging) rated at 5V, 2.5A.

im searching for single cells, but if can give me a compact one. it would be good. i need a pack of 4 and a pack of 6.

IEC definitions of the voltage classes is here: IEC 60038 - Wikipedia

I think for your battery packs, you should be looking at suppliers’ catalogues. There are concerns regarding the use of multiple cells of the type you have in mind in a battery, especially over-temperature protection and the charging regime, and it’s my understanding that the cell manufacturers are reluctant to sell single cells without some assurance that proper charging systems and protection is in place. http://batteryuniversity.com/ is a good resource for information about all types of battery.