Switch 3 phase induction motor by arduino

Hello to all. Sorry if my English is poor. I have a 3 phase Induction Motor and I want to turn off or on by Atmega328p. My circuit is the same as below, when the motor is disconnected from relays, the board works very fine, but when I connect the Motor to the relays and I switch relays by Micro, It goes to restart. Does somebody know what is my problem. Very thank you |500x376

You have a capacitor across the output of your MOSFET driver. Why?

You have good decoupling on the ATmega? This is mandatory.

You have high current stuff well away from Arduino?

You have star-grounding to avoid ground-loops?

Is the 12V supply coming in clean? It needs to be if you are running the MOSFET driver from it, it might benefit from some extra filtering and decoupling.

Cables and box are shielded?

The current path for the relay/MOSFET is separate from the other 12V devices and has decoupling?

first of all, you should not be using three separate relays. You should be using one three pole relay or contactor. the three relays can cause more noise, and can cause problems if one fails to function properly. There should be two power supplies one for the Arduino, And one for the contactor/relay. if only one power supply Is used, make sure the power for the relays is connected as close to the power supply as possible. as mentioned above, shielding and capacitors should be used to cut down noise. and make sure your power supply for the relay/contactor is adequate for the job.

Also, where are you getting your three-phase from. Is it line voltage, rotary converter or is it from a variable frequency drive. You should never put a switch/relay between a variable frequency drive and the motor. This could damage the VFD.

Hope this helps.

Joe.

MarkT: 1-You have a capacitor across the output of your MOSFET driver. Why?

2-You have good decoupling on the ATmega? This is mandatory.

3-You have high current stuff well away from Arduino?

4-You have star-grounding to avoid ground-loops?

5-Is the 12V supply coming in clean? It needs to be if you are running the MOSFET driver from it, it might benefit from some extra filtering and decoupling.

6-Cables and box are shielded?

7-The current path for the relay/MOSFET is separate from the other 12V devices and has decoupling?

1- I have done like Mosfet driver Datasheet. Does it make any problem? 2-Yes I do. 4-Yes I do. 5-Actually it comes from a switching adapter and I have tested many adapter but it still has problem. 6- Yes, I think so. actually I think problem is the noise of source +12v. 7- Yes both current paths is separated from each other. I have connect a 12v 3A battery to power arduino and a 12v 3A switching adapter to power the mosfet and relays. and everything went well. But I don't want to use battery and I want to use just one switching adapter to power all board. What can I do? What do you think.? Very thank you.

promacjoe2:
first of all, you should not be using three separate relays. You should be using one three pole relay or contactor. the three relays can cause more noise, and can cause problems if one fails to function properly. There should be two power supplies one for the Arduino, And one for the contactor/relay. if only one power supply Is used, make sure the power for the relays is connected as close to the power supply as possible. as mentioned above, shielding and capacitors should be used to cut down noise. and make sure your power supply for the relay/contactor is adequate for the job.

Also, where are you getting your three-phase from. Is it line voltage, rotary converter or is it from a variable frequency drive. You should never put a switch/relay between a variable frequency drive and the motor. This could damage the VFD.

Hope this helps.

Joe.

It’s true. When I use an Inverter to power the Induction Motor, there is so much noise. But when I use 3 phase source to power the motor it has less noise.
When I use two power supplies everything goes well.
What can I do if I want to use just one supply to power the board.
Very thank you.

Hi,
Can you post some pictures of your project so we can see your component layout?

What are the specs on your relays? (You should have one relay switching a 3phase contactor.)

Tom… :slight_smile:

Hi,

When I use an Inverter to power the Induction Motor

What do you mean by an "Inverter"?

Tom.. :)

TomGeorge:
Hi,
Can you post some pictures of your project so we can see your component layout?

What are the specs on your relays? (You should have one relay switching a 3phase contactor.)

Tom… :slight_smile:


why 1 relay. if I use 3 relays to switch a 3 phase motor, does it have any problem?
Very thank you.

Hi, Where is your 328?

You are asking for trouble by mounting the controller and relays on the same PCB. They should be separate PCB and 3phase contactor. The contactor being away from the controller.

The picture does not reflect how you have the motor connected in your circuit diagram. Why have you only got two relays connected to motor?

Did you design the PCB, if so can you please post a image of your pattern?

What is the specs of the motor.

Tom... :o

Why are you using a 50 Amp power MOSFET to control 100mA worth of relay coils? A 2N4401 BJT could do that easily. Do you have snubbers across the relay contacts?

leoncorleone: why 1 relay. if I use 3 relays to switch a 3 phase motor, does it have any problem? Very thank you.

A 3phase contactor ensures a reliable and consistent synchronous disconnection of the motor, this way the contacts will be unloaded together and with minimal loading. Have you got an overload fitted to the motor? Again, what size is the motor?

Is the application a phase monitor?

Thanks.. Tom.. :)

TomGeorge: Hi, Where is your 328?

You are asking for trouble by mounting the controller and relays on the same PCB. They should be separate PCB and 3phase contactor. The contactor being away from the controller.

The picture does not reflect how you have the motor connected in your circuit diagram. Why have you only got two relays connected to motor?

Did you design the PCB, if so can you please post a image of your pattern?

What is the specs of the motor.

Tom... :o

Thanks,Actually 328 is under the LCD and also I used 3 relays for 3 phases. The motor is a 3 phase induction motor and is about 1200 watts.

This is my PCB.|500x206

FYI,

A 3-phase contactor assumes a 3-phase AC SOURCE, which the OP clearly does not have.

Second, the absence of any details about the 3-phase controller pcb the OP is using (namely schematic)
makes it difficult to provide help.

A 3-phase contactor assumes a 3-phase AC SOURCE, which the OP clearly does not have.

??

The OP clearly shows a 3-phase supply on the right of his diagram.

I'd look for magnetically or electrically coupled interference - ie use capacitors, ferrite beads, MOV's in strategic places..

I think my first try would be to put small ferrite rings with a few turns of wire in series with each motor lead to slow the switching transients.

Allan

Hi, To prevent the relay contact arc you can use a varistor, They will prevent the arcing when the contact are close/open. Just install them across the contacts.

Apart from anything else, the concept of crossing over the relay output contacts such that all three NO are together, all three NC are together and all three C are together, when immediately adjacent are the three respective relays, is seriously flawed. The phase-to-phase voltages appearing on adjacent terminals will be in the order of 400volts (assuming a 230 supply) and your separation, either sided by side, or through the PCB, is questionable.