12v relay specs 20/30a

'scuse my ignorance...but if the contacts are normally open why would there be a current draw?.........is not the relay either open until it receives the switching power and then when closed allowing current draw through it?

thanks

A change over relay has two contacts. One closed when not energised and the other closed when energised. They may have different current ratings.

EG If you have a look at the Narve range most (all) of their changeover relays have two current ratings.

All their single contact relays have one current rating.

A relay may need to be derated for continous use as opposed to intermittent use eg a horn relay as opposed to a headlight relay.

very clear to me now..........using the multi tester across the terminals has cleared it up ...I didnt realise that there was one closed circuit when not energised........

I can just use this change over relay as a standard functioning 30 amp relay via the 87 pin by ignoring the 87a terminal which is obvioulsy live (and 20 ammp)when the relay is not energised and inactive when the relay is energised


thanks again

thanks all understood

cheers