An Entertaining Conundrum

[KYAvion]

Just allow for a little airflow and you'll be all set.

[silverloaf]

Just allow for a little airflow and you'll be all set.

Thanks.

I think I'll rough-in a small loop of 4AWG to the batteries and leave it unconnected for now. Any recommendations on brand of PSW inverters? Lots of them on-line but reviews seem to be all over the map

Regarding the Ethernet cable:

I ran 25 foot of CAT-6e (with factory ends) during rough-in, unsure how it might be used. Our computer guru recommended it based upon what I thought our needs might be.

The cable runs along the left side of the trailer, behind the cabinets and bed. It begins at the left-rear service compartment to the front of the trailer. I installed a layer of corrugated tubing over the already shielded cable.

Admittedly, we haven't been to a campground in 30 years. We have no idea what Internet service hook-ups are now available. We anticipate purchasing a satellite dish in the future. Should I run dedicated wire for that?

I would at least want to get this type of wiring installed while I still have access.

[KYAvion]

I wish I could help with inverter brands, but I don't know much about them. I'm curious to hear what people recommend though.

That's a good idea to go ahead and run all your cabling now. The layout of my 30R is such that I can pull cables, water line, etc. fairly easily. Otherwise, I'd probably run conduit. Have you considered running conduit for future use in those areas that are difficult to access?

[silverloaf]

I suppose I could have run gray conduit. However, the conduit would intersect the kitchen sink drain into the tank. It’s not a direct shot from back to front.

Instead, I notched the base cabinet partitions at the wall’s edge. I can access the notches from inside each cabinet to thread additional wiring through them.

By the way, when I reconstructed the kitchen baae cabinets, I created a removable false bottom inserts for each one. Easier to clean and a little more finished than storing stuff right on the floor.

[Erehtuo]

That removable false bottom idea is great! I just pulled some cabinets to see what I'm dealing with and I may steal that idea.

[silverloaf]

I should have posted this as a separate topic.

However, I used 1/4” plywood G1S for the bottoms. They rest on 3/4” square pine blocking that is secured to the partitions. The bottoms just float on the blocking.....no fasteners.

Also, I installed 3” high ply strips across the back so stuff doesn't disappear under the bottoms.

[Salty]

Bunch of comments here.
Inverter power output in watts is a primary consideration, however, you need to take a close look at the temperature the output was rated at.
For example. 1000 watts at 40 degrees C (104 F) - which is a standard rating temperature - but as temperature rises, output decreases. My point. When you first arrive wherever you are going or enroute there to, the odds of your trailer being a nice temperate 70 degrees F are slim (with a nod to rerubber and kool seal users, but still..) AND the inverter itself will generate heat. You see where I'm going here
Options are to look for an inverter with its' outp[ut rated at 60 C (140 F) or obtain an inverter with a higher output rating an run it at a lower output (known as derating) so increases in temperature are not an issue.

I agree that the inverter needs to be as close to the batteries as possible. the gauge size is a function of not only current, but distance. Unlike AC where the primary considerations are current carrying capacity and insulation , the primary considerations with DC are Current capacity and Voltage drop. Resistance of the wire is an issue. Correct gauge can be determined using a Voltage Drop Index.
So the below formula comes into play:
VDI = (AMPS x FEET)/(%VOLT DROP x VOLTAGE)
a standard acceptable voltage drop is 3 %
so 1000 watts @ 12 VDC = 83 amps. For our purposes, we will say a 6 foot length of wire from battery to inverter
VDI = (83*6)/(3*12)
VDI = 13.333
Based on that number and the current draw, you are looking at 4 gauge.
Reference the chart here: https://www.altestore.com/howto/wire-si ... tems-a106/

Lastly, modified or pure sine selection depends on what the load will be. Electric motors are not overly happy with modified sine, but will work. Toasters, crock pots, coffee makers are ok with modified sine.
Anything with an electronic control package, not so much. Dedicated electronics (TVs, Radios, microwaves, AC with Comfort Control centers and control boards , refrigerators with a control board) would need pure sine inverters.
Additionally, Inverters can produce electrical noise. Spurious emissions, 60 Hz harmonics , harmonics of the switching transistor frequency all mess with dedicated electronics. Worse, all of the above can be back fed to the DC system.
Lastly, look for a model that is UL approved. UL, RVIA, NFPA or ABYC would be good approvals for an inverter. Beware the less expensive (and unapproved) inverters that bear no standards body approvals.

[KYAvion]

Salty- Great analysis. So I plugged the inputs you mentioned (83 amps, 6ft, 12v) into a voltage drop calculator I use for 120v circuits. I changed the parameters to reflect 12v, and the calculator recommended 3 AWG, which of course would be 2 AWG since I've never seen 3 AWG copper (although perhaps my electrical supply house just doesn't carry it). Per the calculator, 2 AWG at 3% drop can handle 83 amps at the end of an 11.89 foot cable run.

When I input 4 AWG, the result was a maximum distance of 7.55 feet at a 3% drop or less for 83 amps. However, the calculator stated that 4 AWG may not carry 83 amps. While I plugged 12v into the parameters, I take it the allowable ampacity of wire for 12v vs 120v is different as your table suggests?

[Salty]

Allowable ampacity is affected by insulation type

https://www.cerrowire.com/ampacity-charts

[KYAvion]

My understanding is romex falls in the 60 degree category, whereas THWN at the 75 degree category (as your chart shows). Due to heat of the trailer, I wonder if it'd be wise to derate even the THWN to the 60 degree rating.