12v Relay Question - Electronic Circuits Projects Diagrams Free

jbarnaby2000 · 11th June 2008, 12:03 AM

I have a StingPro RL-5x 12v coil relay. From what I have found it has 20 amp contacts. Now this is an automotive relay and it does look like the contacts are rated upto 14v. What I was wondering is if I could switch AC with it and how much current this little guy can take before exceeding its rating.

I have found a link to one on the All Electronics site...
12V SPDT 30 AMP AUTOMOTIVE RELAY | AllElectronics.com

Anyone have any ideas if its current rating can be converted to an AC current rating?

RODALCO · 11th June 2008, 04:05 AM

Not a good idea. The 12 V relay has contacts rated at 12V20Amps DC.

To switch AC at mains potential there is not enough clearance when the contacts are open.

Generally it is harder to break DC current, so 12 V dc rated contacts will break 24 V ac allright at 20 Amps.

Bear in mind that the peak value of 230V mains is 325 Volts !!

Other matter is that the relay is not insulated to the mains voltage level, and a possible flashover might occur between your 12V control circuit and the 110 or 230 V mains.
There are plenty of cheap 12 or 24 Volt control relays about which can safely switch 230 V at 8 Amps or higher.

jbarnaby2000 · 11th June 2008, 04:08 AM

Quote:

Originally Posted by RODALCO

Not a good idea. The 12 V relay has contacts rated at 12V20Amps DC.

To switch AC at mains potential there is not enough clearance when the contacts are open.

Generally it is harder to break DC current, so 12 V dc rated contacts will break 24 V ac allright at 20 Amps.

Bear in mind that the peak value of 230V mains is 325 Volts !!

Other matter is that the relay is not insulated to the mains voltage level, and a possible flashover might occur between your 12V control circuit and the 110 or 230 V mains.
There are plenty of cheap 12 or 24 Volt control relays about which can safely switch 230 V at 8 Amps or higher.

Cool that was the info that I was looking for...thx again...

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11th June 2008, 12:03 AM	(permalink)
jbarnaby2000	12v Relay Question I have a StingPro RL-5x 12v coil relay. From what I have found it has 20 amp contacts. Now this is an automotive relay and it does look like the contacts are rated upto 14v. What I was wondering is if I could switch AC with it and how much current this little guy can take before exceeding its rating. I have found a link to one on the All Electronics site... 12V SPDT 30 AMP AUTOMOTIVE RELAY \| AllElectronics.com Anyone have any ideas if its current rating can be converted to an AC current rating?

11th June 2008, 04:05 AM	(permalink)
RODALCO	Not a good idea. The 12 V relay has contacts rated at 12V20Amps DC. To switch AC at mains potential there is not enough clearance when the contacts are open. Generally it is harder to break DC current, so 12 V dc rated contacts will break 24 V ac allright at 20 Amps. Bear in mind that the peak value of 230V mains is 325 Volts !! Other matter is that the relay is not insulated to the mains voltage level, and a possible flashover might occur between your 12V control circuit and the 110 or 230 V mains. There are plenty of cheap 12 or 24 Volt control relays about which can safely switch 230 V at 8 Amps or higher. __________________ There are more ways to get to Rome. Electricity, Electric clocks, Meters and Trains are great.