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???
01/16/06 14:04
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#107492 - Varistor
Responding to: ???'s previous message
Raja said:
what are the precautions to be taken for using a relay to switch (230v ac power lines)

In order to achieve a long life for the relay contacts a varistor should be used: Use a relay which switchs-off the load at phase and neutral. Then, connect a varistor across phase and neutral on the load side.
When you switch-off the load and there comes some inductance into play, then the varistor and its parasitic capacitance of about 1nF helps the relay contacts from becoming eroded.

Use a 275V varistor and connect a series circuit of two 1M resistors in parallel to it.

Kai


List of 8 messages in thread
TopicAuthorDate
surge/spike suppression??            01/01/70 00:00      
   Depends on the circuit            01/01/70 00:00      
      Varistor again            01/01/70 00:00      
      where should i connect the varistor?            01/01/70 00:00      
         At input of transformer            01/01/70 00:00      
   Varistor            01/01/70 00:00      
      Connect a fuse..            01/01/70 00:00      
         Of course!!            01/01/70 00:00      

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