Aux Fuse Box Question for power to truck bed

[jnack]

I've got a Long Bed Tacoma and my plan is to have a blue sea fuse box along with switch pros under hood wired to dual battery.

for the truck bed I will need power for:
- fridge/freezer
- 12 v water pump (in the future, I will plan to utilize a 12v immersion hot water pump -- currently looking at a 600W unit ~ 50 amps)
- bed lighting
- spare 12v plug/USB

In the future, I may want to add a pure sine inverter (though I'm guessing due to distance and amp draw would need totally separate larger gauge wire).

My question is based on my desired power to the rear would I be better off wiring everything off of the fuse box up in the engine bay OR would I be better off running a sub-fuse box somewhere in the bed of the truck? I'm guessing this would make future wiring less of a pain since I won't have to route wire from under the hood to the truck bed.

thoughts?

 

[s.e.charles]

I try to follow along on the electrical threads because I want to learn more. sorry cannot give any concrete advise, but my gut reaction is the second option of getting the 'sub-panel' close to the point of use. for the reason you mentioned if no other. (well, maybe ease of trouble-shooting, down the road.)

 

[jnack]

bump...

 

[Bayou Boy]

You're going to want to run a very large set of wires to the rear due to the combo of the 50amp pump and the inverter. You really need to do an actual wire loop length and amperage calc and use the Blue Sea table to figure out the size wire to run. Also, you will want to use a buss bar to distribute power because every blade fuse distribution box I know of is rated at only 75amps max. The Blue Sea reference articles are going to be your best friend.

 

[Bayou Boy]

FYI 50 amps at a 30ft run (you add the positive and negative together to get the distance) calls for a 6AWG wire. ^ AWG is tough to find so you're really looking at 4AWG. Thankfully 4AWG will cover 100amps at 30ft with a 10% drop so you're probably good with that.

Know that a 50amp pump plus a decent size inverter is a very big load so you'll need to seriously upgrade the alternator on your Tacoma if you will use them often or long.

 

[jnack]

You're going to want to run a very large set of wires to the rear due to the combo of the 50amp pump and the inverter. You really need to do an actual wire loop length and amperage calc and use the Blue Sea table to figure out the size wire to run. Also, you will want to use a buss bar to distribute power because every blade fuse distribution box I know of is rated at only 75amps max. The Blue Sea reference articles are going to be your best friend.

please excuse my ignorance (im very new all things electrical), my understanding is that bus bars are not fused and are merely a distribution hub -- so this would require heavier duty in-line fuses or circuit breaker?

FYI 50 amps at a 30ft run (you add the positive and negative together to get the distance) calls for a 6AWG wire. ^ AWG is tough to find so you're really looking at 4AWG. Thankfully 4AWG will cover 100amps at 30ft with a 10% drop so you're probably good with that.

Know that a 50amp pump plus a decent size inverter is a very big load so you'll need to seriously upgrade the alternator on your Tacoma if you will use them often or long.

thanks for that, and yeah. the inverter i'm not even sure i would need...it's a maybe (truck has a built in 400W inverter which would be good enough for charging a laptop). the hot water heater although it has a large draw would only be on for a brief period of time -- im also debating carrying a secondary water tank that's smaller for hot water so it will heat quicker and i can use a heating element with less power demands

 

[Bayou Boy]

please excuse my ignorance (im very new all things electrical), my understanding is that bus bars are not fused and are merely a distribution hub -- so this would require heavier duty in-line fuses or circuit breaker?

Yes. Also, regular blade type fuses are not available in 50amp ratings so youd be out of luck there anyway. You'd need to go to a Maxi fuse or circuit breaker. 12v electric water heaters are not even regularly found on RVs due to the electrical load. If you are new to this, I'd camp fora while without the heater to see if you really need it before committing to the significantly more complex wiring it will need.