32 replies to this topic

[Mark G]

There's a zero missing I think:  120/240v.  Around here, only the McMansions need more than 200A service.

[Bad Habit]

NEC Article 551 specifically excudes the wiring within the vehicles.

Yes, but it does cover the wiring within RVs to include truck campers, along with RV Parks.  The only place I have found that refers to identification of conductors is "551.49 Grounded Conductors".  This refers back to 200.6 which is about marking white for Grounded Conductors (as opposed to Grounding conductors which would be green).  Going on the premise that the negative side of the battery system is bonded to the chassis, and that in turn could/would be grounded when plugged into shore power (assuming a non-damaged cord).  That would make the negative a Grounded conductor I guess.

 

I know I've seen another place where the White negative is a requirement, maybe Telcordia (old Bell Labs specs).  It'll bug me till I find it...

[Mark G]

NEC Article 551.1 Scope.  The provisions of this article cover the electrical conductors and equipment OTHER than low-voltage and automotive vehicle circuits or extensions thereof, installed within or on recreational vehicles, the conductors that connect recreational vehicles to a supply of electricity, and the installation of equipment and devices related to electrical installations within a recreational vehicle park.

 

I'm not sure what these provisions do cover then?

 

Great reading if you're trying to get to sleep.

 

Another thing about codes:  they only apply if the Agency Having Jurisdiction (city, county, etc. in my world) has adopted the code as their standards.

[DavidGraves]

I'm not sure what DavidGraves (OP) has in mind, but for me voltage drop is the controlling factor.  My batteries need 14.4 volts in absorption.  To get that I need 4 AWG wire.

 

If my batteries are at 50% they can accept 30 amps:

 

my alternator puts out 14.7 volts,

2% allowable voltage drop = 14.4 volts.

 

22 feet round trip alternator to house batteries, 

200ºF wiring temp rating,

60 amp fuses on both ends,

connector between truck and camper,

 

= 14.4 volts at house battery = happy battery = 

 

jim

Hi

 

I am gonna hijack my own thread here and ask a wiring question.

 

I am routing 4 ga into camper to a 50 amp fuse block about 6 inches from my battery isolator/separator.....

 

There is a factory install thermal reset 30 amp breaker  on the hot lead between isolator and battery.

 

Can I replace this with my 50 am fuse block at this same location ?

 

My need is to fuse energy from house battery into camper main harness.

 

Many thanks

 

DavidGraves 

Edited by DavidGraves, 09 February 2017 - 01:04 AM.

[JaSAn]

. . .

I am routing 4 ga into camper to a 50 amp fuse block about 6 inches from my battery isolator/separator.....

 

There is a factory install thermal reset 30 amp breaker  on the hot lead between isolator and battery.

 

Can I replace this with my 50 am fuse block at this same location ?

 

My need is to fuse energy from house battery into camper main harness.

 

 

A 30 amp breaker (fuse) is max size for 10 AWG wire.  I am assuming that the breaker was sized for the wire, so the answer is no.  Fuses are always sized for the wire gauge:

 

http://bdfuses.com/fusesnwires.php

 

The size of the fuse from house battery to camper harness should also be sized to the wire.  Is the camper harness run through a fuse block?  Correct wiring should be: house battery to fuse block, fuses in fuse block protecting individual circuits in camper.

 

jim

[DavidGraves]

Thanks Jim

 

So far here is what I doing.

 

Truck battery to 50 amp reset circuit breaker-

 

Negative and Hot 4 ga wire run to anderson plug in truck bed.

 

Negative 4ga direct to house battery......12 ga back to camper ground bar.

 

Hot 4ga to a  ????????

 

On hold where to place house battery fuse.....??????

 

Original wiring was 12 ga from truck battery negative to ground bar to camper battery and 12 ga truck hot to Battery separator to 30 am thermal reset breaker to house battery.

 

My thinking is to leave 30 amp thermal reset in place and install 50 amp fuse just before battery separator....

 

Eager for clarity on placement of camper end 50 amp fuse.

 

David Graves

[Squatch]

Put your fuse/breaker near the camper/house battery. That way you have one on each end near the batteries. This protects all the wiring between them. I used marine disconnect style breakers. This can also be used as a switch to disconnect the batteries for service work ect. It also kills the juice to the truck wiring if the camper is not connected.

 

Main fusing is always best near the source. This leaves little unprotected wiring.

 

Connect all loads downstream from the fuse/breaker.

Edited by Squatch, 09 February 2017 - 05:36 PM.

[Vic Harder]

Put your fuse/breaker near the camper/house battery. That way you have one on each end near the batteries. This protects all the wiring between them. I used marine disconnect style breakers. This can also be used as a switch to disconnect the batteries for service work ect. It also kills the juice to the truck wiring if the camper is not connected.

 

Main fusing is always best near the source. This leaves little unprotected wiring.

 

Connect all loads downstream from the fuse/breaker.

Not disagreeing with Squatch... clarifying, maybe...

 

If you have a 50A reset at the truck battery end, put another one just like it at the other end too, so after your Anderson Power Pole connector in the truck bed, the hot wire comes into your camper and heads off towards the separator/battery box.  Put it in line there, between the Anderson plug and the Separator.

 

The existing 30A is now redundant.  Re-purpose it maybe?  Do you have a fuse/switch in the DC load side?  IF not, put it there.

 

Just my thoughts.

[Squatch]

Actually I prefer one at each battery. This provides total circuit protection. The one in the truck protects to the separator. I think FWC provides one at the separator location just in case there is not one at the truck battery. In that case it isolates the camper from the truck if something goes wrong.  

Edited by Squatch, 09 February 2017 - 11:31 PM.

[DavidGraves]

Thanks to you both !

 

I think I have it under control but we are talking safety here.....so here goes again.

 

There is a factory 30 amp thermal breaker between separator and the house battery.

 

Is this correct location for my house battery 50 amp fuse ?

 

Hi Vic, you think it should be before the separator.

 

Is there separator function that you think it will affect ?

 

I think we are all keeping me safe but my only reason for routing  the 4ga is to try to insure "better" charging of my house battery. 

 

Keep it coming fellows....we hope to head south this weekend.

 

David Graves

 

North Oregon Coast