Need help for motor driving with triacs

mesuthh

Jan 17, 2011
3
Joined
Jan 17, 2011
Messages
3
Hello people;
I really need help friends
I am tring to drive a single phase (230V AC) motor 4A with BT137(8A), but triac gets hot like 35 celcius degree (even I am using cooler) and after some switching it is getting failed. So that later on I have changed the triac with BTA41(40A) and heatshink, but it is still hot around 30 degree, and in one week BTA41 also gets failing. I am tring to drve the triac with Moc3041, and I am tring to switching the triac when 5Vdc available on Moc3041.
I have tried to use snubber but it is not solving the problem
you can reach the view of my circuit on 
soru1h.jpg


here I am triying drive the motor with 5V dc control to moc3041 so triac fries and the motor starts, and one more think I am also drving a 25uf 400 V capacitor (paralell with the motor) with that motor for compansating

if someone has an advice I will be really thankfull to him/her
Regards

 

Hero999

Oct 28, 2007
2,433
Joined
Oct 28, 2007
Messages
2,433
TRIACs don't like switching capacitive loads.

You probably also need a snubber network to protect the TRIAC from the back EMF.

 

mesuthh

Jan 17, 2011
3
Joined
Jan 17, 2011
Messages
3
thank you for your reply sir
I have tried a snuber network as moc3041 datasheet advice but it did not solve my problem.
do you have a specific idea for snubber for this circuit, or is there any calculation for snubbing depending for the load
regards

 

cachehiker

Jan 11, 2011
4
Joined
Jan 11, 2011
Messages
4
Basic 2 or 4-pole induction motor? Any idea of its resistance or inductance?

I think the snubber is likely where it's at. What values did you use?

You may have to use a larger one to limit 1000W of reactive load to 25 V/

 

GelecG1

Sep 14, 2008
3
Joined
Sep 14, 2008
Messages
3
I have driving 2.2 HP single phase ac induction motor with capacitor like you.
AND bta41 failing.

snubber and zero crossing is correct.but bta41 in full load suddenly failed.

can you help me?

 
K

kimico

Jan 1, 1970
0
The two motor driving rollers of the centrifugal casting machine must keep synchronous and keep load balance。 ;D

 

hotwaterwizard2

Jan 8, 2004
2,022
Joined
Jan 8, 2004
Messages
2,022
7831-cat_out1.gif

http://www.electro-tech-online.com/electronic-projects-design-ideas-reviews/93323-switching-ac-loads-triac.html

I think the resistor is too small needs to be 330


BT137 Datasheet

http://www.nxp.com/documents/data_sheet/BT137_SERIES.pdf


BTA41

http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00002263.pdf

Moc3041 Datasheet

http://www.electro-tech-online.com/custompdfs/2009/05/moc3041.pdf

 
Last edited by a moderator:
C

ccsintlcircuits

Jan 1, 1970
0
This one is the great post in which we get information regarding the power driving motor.

 
S

swarner11

Jan 1, 1970
0
'hotwaterwizard' you told us very thoroughly, thanks for your links but I found a little error in Moc3041 datasheet.

 
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