Relay question

[mackmaster]

Hi guys
I have an Omron relay part# G5V-1-DC24 with contact rating:
1A at 24 VDC
or 0.5A at 115VAC
I want to use it for 12VDC ,is the rating of the contacts remain at 1A or could be more than that?
Thanks

 

[VEBill]

The relatively small difference between 12 and 24 volts would probably have a negligible impact on the current rating. So it's best to assume the contact rating remains at 1A.

The type of load has impact on contact life as well.

 

[waross]

I would take the ratings as maximums;
On DC, the maximum current is 1 amp and the maximum voltage is 24 volts.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[mackmaster]

Thanks for help.
Also, I would like to know why that differences between AC and Dc ratings ?
If I use it for 24VAC is the current rating remain at 1A?

 

[carnage1]

I don't have an Omron catalog but I would be comfortable running it as a 1 amp rated relay (with your standard safety factor built in). Somewhere in the catalog should be a section on interpolating the printed ratings to match their design standards.

Luck is a difficult thing to verify and therefore should be tested often. - Me

 

[BrianG]

Mackmaster,

The difference between AC and DC voltage ratings applies for most relays, and is higher for AC. This is because on AC any tendency for the contacts to arc on opening tends to be quenched when the voltage changes polarity on the next half cycle. With DC, an arc, once started, will tend to persist, so keeping the maximum voltage rating lower helps avoid this problem.

 

[roydm]

The Data sheet lists the "carry" current as 2 Amps. I am unfamiliar with that term, what does it mean?
Roy

 

[BrianG]

The "carry" current means the maximum current that the contacts can handle once they have completely closed. This is different to the maximum current (AC OR DC) as this is the current permitted that the contacts can SWITCH (either closing or opening)without damaging the contacts.

 

[waross]

Good design practice would be to use the values in the graphs under "Characteristic Data" as maximums. Exceeding these values will probably result in shortened life of the device and may lead to problems interrupting currents greater than rated currents. I would forget about the "Carry Current". It is not usually practical to use in designs. It is dangerous to use a relay or contactor to carry more current than it can safely interrupt.

Bill
--------------------
"Why not the best?"
Jimmy Carter