20 replies to this topic

[Mderou]

My only comment would be to ensure there is a similar breaker (I just use regular reset-able circuit breakers) at the Aux battery side if there isn't one already. You want the breaker as close to the battery as possible on both the truck battery and camper battery.

Would a 30 amp inline fuse suffice? I have half a dozen of those laying around. 

[Mderou]

The 7611 ACR will work fine.  It will sense either side so it will close when either side voltage rises above the setpoint.  If you have solar this will keep your stating battery topped off.  My truck battery is drained after 2 weeks so now it is topped off daily while it is parked outside. 

 

In my case I had the 7611 installed under my truck bed before my camper to isolate and charge my ham radio gear and aux battery. In the past I have bypassed the camper's stock relay in favor of my dual sensing ACRs but with my new Hawk with solar, the internal camper relay is always on when needed so I left them in series, been working fine.

 

The ACR when located near the truck bed power connection Attwood connector) can act as a terminal strip making for easy transition between 6GA wire for the truck battery/breaker and the 10GA wire on the Attwood connector.   The short bit of 10GA won't affect much.

 

Mike

K7MDL

Thank you for the input. I don't have solar yet unfortunately, that is next summers plan.  I planned to solder that joint at the attwood connector with the 8Gauge-to-10G. 

[Mderou]

I don't have Clearance/Marker lights in my Grandby, as such the third prong of the attwood plug can remain dead. Should I run a hot wire there anyway just in case I may need to use it in the future for other things? I read somewhere about someone using that power source for their dc-to-dc charger. Sorry for the obscure conceptualizing, but electric stuff always serves challenging. 

[K7MDL]

I don't have Clearance/Marker lights in my Grandby, as such the third prong of the attwood plug can remain dead. Should I run a hot wire there anyway just in case I may need to use it in the future for other things? I read somewhere about someone using that power source for their dc-to-dc charger. Sorry for the obscure conceptualizing, but electric stuff always serves challenging. 

I would not run any wire until you know the final usage.  There is a good chance the wire size needed then is not what you might run now causing rework.   You could run a new signal wire into the camper through that connection for turning on stuff like rear flood lights from the cab.

[Mderou]

I would not run any wire until you know the final usage.  There is a good chance the wire size needed then is not what you might run now causing rework.   You could run a new signal wire into the camper through that connection for turning on stuff like rear flood lights from the cab.

Good point, Floods are on my to-do list. Would 12 Gauge suffice here? I bought a spool recently. Perhaps I'll finally use an upfitter switch for that. 

[K7MDL]

For LED floods 12GA would more than enough though its large size diameter may make routing through your camper and walls difficult.  I would imagine you would run the floods off your camper battery via the 12GA wire, a fuse, and a relay in parallel with a switch, both in the camper.  Then can run a small 16GA wire between the cab and camper to the relay.

 

For determining wire size you can use an internet calculator that considers wire length, load current and allowable/tolerable voltage drop.  Go one size up if in doubt.  A relay is very low current to the voltage drop is minimal.  Lights can be 10%.  Bigger wire is less voltage drop.  Lots of online calculator and charts but this link is a good start.   Select your desired lights, look up their max current draw.  Figure your wire length between the battery source and the lights.

 

Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems

Edited by K7MDL, 20 August 2022 - 07:07 PM.

[Mderou]

For LED floods 12GA would more than enough though its large size diameter may make routing through your camper and walls difficult.  I would imagine you would run the floods off your camper battery via the 12GA wire, a fuse, and a relay in parallel with a switch, both in the camper.  Then can run a small 16GA wire between the cab and camper to the relay.

 

For determining wire size you can use an internet calculator that considers wire length, load current and allowable/tolerable voltage drop.  Go one size up if in doubt.  A relay is very low current to the voltage drop is minimal.  Lights can be 10%.  Bigger wire is less voltage drop.  Lots of online calculator and charts but this link is a good start.   Select your desired lights, look up their max current draw.  Figure your wire length between the battery source and the lights.

 

Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems

Thanks for the great information and link. 

[mobilelists]

I am in the process of changing some of the wiring in my camper.  Does anyone know if it matters if the Blue Sea 285-Series Circuit Breaker - Surface Mount is mounted sideways?  It would make it easier to route some wires if I can mount the breaker sideways instead up up/down.

 

Stay healthy,

Pat
 

 

[craig333]

I've never seen a breaker that matters how its oriented. Might be confusing to someone else down the road but I think you'd be okay. 

[mobilelists]

I can see a potential issue if a standard breaker was upside down. In that case...off would be up.