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How to avoid Spark at relay contact ?

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binu G

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hi,
can any one suggest a solution for avoiding the spark at the relay contact for a AC inductor load ?

Thanks
Binu G
 

dipal_z

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As far as i know you can prevent it by adding a capacitor across relay contacts but i don't have enough information about selecting its value.

Same technique is used in florescent tube light starters as well.
 

IanP

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B) If you are using a relay to switch an AC-powered inductive load, put a
varistor in parallel with the load. The varistor voltage rating should be about
1.5 times the peak-to-peak steady-state voltage of the load.
C) Relays switching an inductive load may require a capacitor placed across
their contacts. 0.1ufd to 1.0ufd is a good starting point. If the relays are
switching an AC load, place a 100 ohm resistor in series with the capacitor.
Quoted from: http://www.jkmicro.com/documentation/pdf/inductive_loads.pdf

Regards,
IanP
 

hr_rezaee

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you must use a flywheel (protection) diode.
see power electronic books.
 

Davood Amerion

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Use snabber :
connect (0.1uF-1.0uF series with 10-100 ohm) parallel with load or relay contacts.
 

myacirkhan2

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should i connect capacitor and resistor on both phase and neutral ?

and it is necessary to use both neutral and phase through relay or only phase?

pls help
 

kabiru

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You can connect it on the load to your relay contact.
 

Slammer

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Snubber (R-C) is OK for most cases.
You can get better results with a transil or varistor across contacts.
 

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