[SOLVED] suppress spike of contactor

[larten]

hi
I use contactor to control my ac motor
but when it changes the direction there are some spikes that sometimes reset my micro

when i google my problem some says that i should use snubber
is it the best way or not?
where shoild i use RC snubber? in parallel with contacts or coil

 

[horace1]

may be worth having a look thru the application notes on Microchips Motor Control page
https://www.microchip.com/pagehandler/en-us/technology/motorcontrol/

 

[paulfjujo]

hello

Could you post your schematic?
If your contactor has a DC coil , you need a diode (anti-retour = reverse way) accross it.
You can put a RC snubber 100 Ohms in serial with 47nF (400V minimum) accross the used contact.

What is the power of your motor ?

 

[goldsmith]

Hi larten .
there are some suggestions : 1- use a low value capacitor ( e.g 4.7u ) pretty nearby supply pins of your micro . 2- use an LC filter for your motor 3 - use an snubber network 4- use a suppressor filter ( kind of EMI filter )
Best Wishes
Goldsmith

 

[larten]

If your contactor has a DC coil , you need a diode (anti-retour = reverse way) accross it.

I place diode in reverse across my DC coil

ou can put a RC snubber 100 Ohms in serial with 47nF (400V minimum) accross the used contact.

isnt it beter to use one o these circuits

2- use an LC filter for your motor 3 - use an snubber network 4- use a suppressor filter ( kind of EMI filter )

could you explain more?


if it could help I use relay to drive my contactor and it has reverse diode and transistor and I use 3 phase motor

- - - Updated - - -

I put RC between each phase and it eliminate most of spikes

I wonder if it won't harm my motor

 

[paulfjujo]

This link (even in french) show all possible solutions..
**broken link removed**

 

[goldsmith]

could you explain more?

Hi again
Certainly ! if you use a differential filter before supply of your control section with ability of attenuate an special BW that is in your problem , thus there won't be any problem .

if it could help I use relay to drive my contactor

It will be same !
Best Wishes
Goldsmith