Relay Amp's In This Circuit - One For The Guru's

[Shaunous]

Hi Guys,
I just wanted to ask the guru's about this harness i'm making for my Redarc bcdc1240 battery management system.

The Instructions call for a 60A Resister Supressed Change Over Relay, this is to switch between alternator feeds and solar panel feeds. The circuit is running a 50A fuse, and 8B&S cable

My question is, as I have an abundance of them, can I use a 40/30A relay with resister, or is the relay going to blow before the fuse ever gets a chance to protect it, even though its only 10amps diff in that 8B&S cable.

Cheers,
Shaun....

[the evil twin]

I'd use a 60 Amp relay as specified.

There are times when that cct will use a fair bit of grunt from the battery. You won't see anything like that amperage from the Solar of course.

You could hypothetically use two 40/30's in parallel but in real life you would never bother

[Yendor]

Hi Shaun,

The problem with using a relay that is rated lower then specified is the contacts in the relay aren't designed to carry that extra amount of current.

So what will happen is the relay contacts will burn out quicker.

The fuse won't prevent this but if the current rises above the 50 amps it will still blow.

If it was me, after spend the coin on the Redarc unit I would purchase the relay they recommend and wire it up exactly as they recommend.

The last thing I would wan't to do is give them a reason to knock back a warranty claim.

Cheers Rodney

[Shaunous]

To easy guys, I thought as much, but just thought i'd ask. I have a million 70A relays also, but their only 4way relays. Damnit.

Haha, oh well, i'll find a reason to use them all one day i spose.

Cheers,
Shaun...