Running #4 awg wire from battery to converter ad inverter.

[TitanMike]

I have a Micro-Lite 25BDS with the Converter mounted a good 15 feet back from the batteries. I want to mount my inverter close so I can use a transfer switch to provide 120V AC to all outlets when boondocking. The switch I want to use will be one with separate A/C circuit breakers so I can disconnect all the high current items like A/C, Microwave, Water Heater, Refrigerator, etc and merely power up the outlets so I can run TV or any small A/C appliance that uses less than 600 watts. (size of TSW inverter was my choice as I have a generator for the big stuff).

I want to feed the Inverter with a #4 awg wire and also upgrade the connection from converter to battery for less voltage drop and more efficient battery charging when the generator is running.

The question regards where I should run the #4 wire. If I try and route the wire inside the trailer I run into all the obstacles imaginable. One side has a slide so I can't just tuck it in the corner between wall and floor like was done on my old trailer w/o slide.

Best way SEEMS to be routing the wire along the frame under the trailer. Should I route it inside the belly cover or just along the bottom that is outside the frame then make a floor penetration into the area where the Converter and Inverter will be mounted?

The simplest way would be to run it outside, along the frame and it would be more labor intensive to open the belly cover to go that route.

If I go outside the frame I'll use some ribbed material that's used to make wire looms in engine compartments to protect the wire from flying gravel, etc. Any pro's or con's to either method? I'll be running two #4's to the Inverter but leave the existing negative connection from the Converter as is. It's just a connection to the frame and on the other end the battery negative is also connected to the frame. Wire was inexpensive enough I didn't need to get cheap and use the frame for the negative on the high current run to the inverter.

I welcome any suggestions based on other's experiences.


Mike

BTW, I am also adding some other upgrades to the 12V system as well. A Victron 702 Battery Monitor with the shunt near the battery in the negative connection and the meter remotely mounted near the factory power panel. The positive wire will have a 100 amp fuse also mounted near the battery to protect the 15-20' of #4 wire running to the Inverter.

[Summer2Go]

Hello Mike! So glad to hear you on the Forum, thought you got lost in Colorado. With my solar wires I went through a few cabinets, and then down through the floor. I ran my wires under the trailer along the frame to where I had to come up. I don’t have a slide, but it’s a small Roo, and probably just as tight for space. I zip tied a bunch underneath the trailer, and sealed it, but I was looking for that wire covering you mentioned. I’m in teacher mode right now, and only visit the forum occasionally. So glad to hear you........waiting for next summer break!

[TitanMike]

Originally Posted by Summer2Go

Hello Mike! So glad to hear you on the Forum, thought you got lost in Colorado.

Never made it to Colorado. Three weeks before I was due to leave I had a minor heart attack (so said my Cardiologist) but attempts to install a stent or two actually ended up with me having a "CABG" which is what they call bypass surgery now. Four bypasses were installed.

I'm starting to feel frisky again and working on my upgrades so I can get out of town sometime in late March.

This Summer I plan on using an old fashioned map of the US and a Dart. Only come home once a month to make sure squatters haven't moved into my house and pay my bills. Then toss the dart and off again.

Since most of the FROG rally's seem to be in the middle of the country I might even plan on attending one and enjoy the trip each way to the max.

[ejohnson1144]

Is there a way to attach a conduit next to the frame ? That would give you ultimate protection. Or maybe flexible seal tight.

[Bluepill]

IMO, no reason at all to not use the frame for ground/negative. Just double up on the connections with a short jumper from the existing frame connections to a second one an inch or two away. Then you can use the extra wire to run a second parallel positive line for even lower voltage drop.

[TitanMike]

Originally Posted by ejohnson1144

Is there a way to attach a conduit next to the frame ? That would give you ultimate protection. Or maybe flexible seal tight.

I didn't think of conduit. Non Metallic conduit secured with regular conduit clips that fit over the flange of an I-Beam would do the ticket. I doubt there would be enough heat generated that I'd need to worry about running any super-sized conduit .

I plan on putting a stainless Steel grounding stud in the straight frame rail rather than what the factory uses which is just a self tapping screw into the formed sheet metal the A-frame of the hitch is made of. Probably the same back at the Converter. I have points where I can strip paint off the frame and reach both sides so I can use the stud secured with lock washer and nut. a 3/8" stud will carry a lot more current than a #10 Self tapper.

I subscribe to the so called motto of the original Mythbusters ---"Anything worth doing is worth over-doing." I learned on boats that there is no such thing as too large a wire when running 12V any distance.

[ejohnson1144]

That would seem to be safer and don't forget fuse protection.

[Bluepill]

Solid connections are a good thing.

Sketchy ones, not so much................




"Honey, I think I smell something burning"

[TitanMike]

Originally Posted by ejohnson1144

That would seem to be safer and don't forget fuse protection.

An ANL-100 fuse at the battery for the #4 wire.

[johnbryanpeters]

This circuit breaker would be a more traditional approach:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[TitanMike]

Originally Posted by johnbryanpeters

This circuit breaker would be a more traditional approach:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I know that they are more traditional but I prefer a fuse on a high current circuit. If I have a fault capable of blowing a 100 amp fuse I want to fix it before heating up the circuit again. C/B's that reset after cooling just continue to throw huge amounts of current into the fault and can do more damage than the at the start.

Even though the high current CB's require manual reset as a rule, I find a fuse to be just a good old reliable method, especially the ANL type that is a "bolt in". Just keep a card with two spares taped near the fuse location. Another use for Duct Tape.
Just my preference.

[fbuckwalter]

It is probably over doing it but an internal star washers between the nut and frame with might reduce the contact resistance of the wire to stud to frame etc.

https://www.seastrom-mfg.com/washers_lock.aspx

They come in stainless too. Probably Granger is a good source.

Enjoy!
Frank B