Relay question

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The RT424024 relay

[url]
http://relays.tycoelectronics.co...
[/url]

has 2 separated contacts. On the top of the plastic of the relay it says 8A/250Vac.

1. What exactly this means???
8A on each contact so 16A totaly or
8A totaly so 4A on each contact.

How much could this current (totaly) could be for a load warking at 24Vdc and not 250Vac???

Thanks.

Michael.

Michael.

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Quote:

8A on each contact so 16A totally

At 24V DC you should get the same provided your load is not inductive, eg, motor load. Inductive loads tend to produce sparking when the contacts open, causing the contacts to stick and/or wear out. Be conservative if you are using an inductive load. There are automotive class relays which are built sturdier and are recommended for those situations.

If you think education is expensive, try ignorance.

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Also, paralleling the switches is not really a good idea, as the (small) delay between the switches will tend to momentarily overload one of the switches. Better than nothing, but try to get a bigger relay if you need to switch more current.

If you think education is expensive, try ignorance.

Last Edited: Wed. Sep 10, 2008 - 05:55 PM
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The 250V value means that it is "safe" to use in 250V circuits. That is, the contact spacing, when it is open, will NOT allow arc between the contacts at 250V. It also means that when the relay opens while load current flows, the resulting arc between the contacts will not damage the relay AND the relay opens far enough so that the arc will stop.

Normally, these relays are used to switch both sides of a circuit carrying current to a load (ie, a motor or a heater, for example). So, it is expected that there will be the rated current (8 Amps) in both contacts. Thus, the current rating is the rating for each contact, independently.

DC is a different "ball game". Arc is much worse than same voltage AC. You would be better to use a relay designed for DC loads.

Jim

 

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