Mega 2560 + MPU5060 + HD44780 + 4 chanel relay module + 400V three-phase motor

Hello,

i have a machine with two 400V three-phase motor, one of these change the angle from an shaft and one to move an conveyor.

so i programmed an Original Arduino Mega 2560 with an MPU5060 to get the angle from the shaft, an HD44780 to display some information’s.
To move the motors forward or backward I use a “Sunfounder 4 Channel 5V Relay Shield Module” on to are connected 4 ABB relays.

If I try anything without the 400V motors all works fine.
If I connect the motors and try to move the motors sometimes the display shows strange symbols and sometimes the program hangs.

It is very strange, I don’t understand why it works without motors and with the motors it makes problems.

Anyone have an idea?
Sorry for my bad english!!
Thank you very much!

Well, The drawing shows the relay board ground is not connected to the Arduino ground.

Paul

Hi,
You need to keep ALL your controller wires away from the 230Vac.
Can you post a picture of your project please?

Thanks.. Tom.... :slight_smile:

Paul_KD7HB:
Well, The drawing shows the relay board ground is not connected to the Arduino ground.

Paul

Thanks Paul for the answer but first I tried to use the 5V power from the arduino to run the relay board, but I haved always the problem described first. In the manual from the relay board I have found that I can run the relay board with an external 5v power supply and there is not required to connect the GND to the arduino. The relay board works perfectly but always with the same problem.
Sometimes the display shows strange symbols or the program hangs completely.

TomGeorge:
Hi,
You need to keep ALL your controller wires away from the 230Vac.
Can you post a picture of your project please?

Thanks.. Tom.... :slight_smile:

Hi Tom and thank you for the answer, the 230Vac wires and the ABB Contactors are completely seperated. At the moment i cant send some pictures. I think in the afternon i have the possibility to take some picture and send them.

I have also tried to disconnect the motors from the ABB Contactors and test it without motors and there are no problems, so the problem is only if the motors are connected.
Any other Ideas?

The motors connected work with 0,18kw and 0,6kw, both 400Vac

Update

On the first pic I forgot the 3 buttons to controll the system
Now I attached the Overview (see picture, Blue line is the input power) of the machine, on the left side top in middel is the Arduino with the control panel (see picture), to the other side is one motor.
The ralay board is for testing not fixed inside of the machine, it is on the ground savely in an plastic container whith is about 50 cm away from the ABB contactors.

I hope this help

Overview.jpg

Controll Panel on.jpg

Standard Arduino relay boards are not rated for 3-phase power (which is 415Vac between phases).

Its not clear if your relays are controlling the contactors or switching the phases?

If the latter note that standard relay contacts will burn out on an induction motor load without
appropriate snubber circuit, and you are exceeding the design voltage of the relay board.

Your crashes and problems may be curable by using the relay board fully opto-isolated (many relay
boards support this if you provide separate power to the relay board), but first checkout the
basic safety issue of employing single-phase equipment on a 3-phase circuit…

Hi,
The arduino relays are only switching 230V to the contactor coils of the 400V motors.

Tom.. :slight_smile:

Exactly the Arduino Relay are only switching 230V to the contactor.
Can I maybe resolve the problem using an opto isolated board?

I have read on the page for the relay board and i found find out that this board use 4 optocoupler
https://www.sunfounder.com/wiki/index.php?title=4_Channel_5V_Relay_Module

Any other ideas?