RC snubber support required

Thread Starter

Ravi Kumar 2

Joined Mar 8, 2016
10
Hello expert,

Please refer attached image for My issue ,

I have connected RC snubber across Relay contact. RC value is 220 ohm & 0.1uf, one contactor is operated by this relay.

but when i deenergize relay coil, contactor does not get off. need your support.
 

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ericgibbs

Joined Jan 29, 2010
21,439
hi Ravi,
What are the ratings of the relay contacts and the load.?
It could be the contacts are 'welding' together, contacts maybe well worn.??
E
 

Thread Starter

Ravi Kumar 2

Joined Mar 8, 2016
10
relay contacts are 7 Amp rating, & Load is less than 1 ampere, if i remove snubber than it works well. so contact is not sticked.

some other issue is there.
 

ericgibbs

Joined Jan 29, 2010
21,439
hi,
When it is in the fault state ie: can you see if the relay contacts are really closed, when they should be open.?
Thats if its possible to see the contacts.??
 

Thread Starter

Ravi Kumar 2

Joined Mar 8, 2016
10
I broken the Relay & checked physically, relay contact is open, but still contactor contact is not open, it means snubber is able to supply the holding current. so what value of snubber should i have to use. contactor coil resistance is 1.58 kohm
 

ericgibbs

Joined Jan 29, 2010
21,439
hi,
Thats suggests the 0.1uF is defective, do you have a spare.?
The combined 200R and 0.1uF are about 30k ohms, which should not allow sufficient current to energise the load.
Do you have a 0.01uF or 0.047uF you could use as a test.??
E
 

Thread Starter

Ravi Kumar 2

Joined Mar 8, 2016
10
i tested with 1K in place of 220ohm but still its not open. tested with 300K then its working ok

so what will be proper value for R & C
 
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