remote power question

**Champak** · 12-06-2012, 08:45 AM

I called the manufacturer to ask them about the amps running up the remote line and they said dont worry about it because the product will only draw what it needs. This doesnt make too much sense to me because that is pretty much any device will only draw what is needed, but we still fuse them. The point is to protect it and what is the minimum and breaking point as far as the amps needed. I tapped into a line off my factory amp the manual calls the line "acc power supply battery voltage" (looks like 20 awg) NOT "battery power supply". My main fear is thinking the remote line doesnt it just receive what is sent to it rather than actually draw the power? And if the amp is drawing x amount of power, and that iz what i am tapping wont it mess up the product if it is too much? What is the maximum number of amps that can be running through the remote line? do I need to put a fuse on the remote line? Am I over thinking this as manufacturer seemed to tell me?

Thanks.

**OldSpark** · 12-06-2012, 06:13 PM

Not that I'm an amp or audio expert - refer to others here else the12volt.com.

But the remotes I have seen are mere low-current inputs that energise the amp's main power. Usually they energise a relay direct though some might energise electronic circuits that energise the relay (or solid-state relay else "kick" the amp's PSU into operation).

Hence they should be from mA to maybe 2A (assuming the man power is connected to other terminals).

And hence too how fusing probably won't protect the amp's remote - it's like fusing a LED or relay coil - pointless. EXCEPT to protect the device powering the remote (or LED or coil etc)...
IE - If the thing supplying the remote can only handle 1A, then a 1A or smaller fuse to protect it and its 1A or greater rated wire to the remote in case that wire shorts to GND, or the amp's remote has some internal short or fault.
IOW the fuse is then merely the normal consideration - protection of the source and its distribution (wire etc).

As to the comment "don't worry .... the product will only draw what it needs" - yeah, a frigging useless comment, and self apparent to anyone with a bit of knowledge. (Hey man, don't fuse anything because they only take what they take - including when they short!)
YTF can't manufacturer's supply the SIMPLE detail - the remote draws 450mA for its relay coil, or 15mA for its transistor circuit, etc? And stuff like "it's protected from external relay spikes and surges" or +/- 100V inputs etc?
[And some wonder why they go out of business or lose sales to elsewhere!]

If the remote itself is the main power feed, then that's a different kettle of fish. But them IMO it is not a "remote", it is the "power" input. And all things tied to any input are "remote" if anyone wants to use that argument.

And be aware, I am aware of cases where the remote does draw lots of power, especially when the main power fails. But IMO that's the result of a fault. (I think one used solid-state inputs and relays and it probably failed in short-circuit mode (ie, low current paths ties direct to high-current rails); maybe a Sony amp?)

**soundman98** · 12-06-2012, 06:30 PM

^correct, but i'll offer a short summary

99% of any devices that uses a remote turn-on wire will draw less then 500mA on that wire. in most cases even less then that.

what product are you referring to?

**Champak** · 12-06-2012, 10:54 PM

It's a rockford fosgate 3sixty.3 (yes it's a seporate remote and power wire). And then the remote wire from that relays to the aftermarket amp. So I dont need to put a 1 or 2 amp fuse to protect the 360? But I should still put a fuse to protect the factory amp just in case right?

**soundman98** · 12-07-2012, 07:13 PM

you do not normally need to add a fuse to the acc wiring because typically the car will have a fuse for that wire that is adequate for most cases. but it's best to always fuse the main power input of any device.

99.9% of the time, if the device fails, it's going to do something funky with the main power input. rarely will any part of the acc circuit in a device lead to a terminal failure, and even less rare for it to cause issues outside of the device..