Installing Hubbell Shore Power Inlet

[sandman]

Hey Guys,

I am making VERY slow progress getting my Little Guy ready for it's maiden voyage next week. I ordered a Hubbell 30 amp Inlet and extension cord and they just got here yesterday. Tonight, I nervously took on the task to boring out a 2 1/2" hole through the side wall. Boy, let me tell you...taking a hole saw after a brand new teardrop wall is a bit disconcerting. After putting the drill to the wall 3 times, I finally got brave and committed to drilling through the wall. Everything went fine and I made sure to use a new holesaw with a bit of lubricant to keep it from getting hot. Here is some pics of tonight's progress as I move forward trying to power up the teardrop.


Here's a pic of the outer wall right after I bored through it with the holesaw. I did halfway from the inside and the other half from the outside and I got very minimal splintering of the wood and fiberglass covering.


Here's a shot from the inside in the galley area showing the cutout for the Shore Power Inlet.


The inlet has been lined up and screwed into place temporarily.


The Hubbell Shore Power Inlet with the hatch open showing the 3 prong 30amp plug. The extension cord will screw onto this making a watertight seal.


Here's the back side of the inlet with the cord strain relief temporarily installed.


Not too bad for a first time modification on the Little Guy.

Now, since I shared pics, I need some advice everyone told me not to use Romex to wire the inlet to the converter since it's so stiff.

What gauge braided wire should I use to wire the inlet to the converter?

I also bought a WFCO 8735 3 Stage Converter which I have NO place to put it since room as at a premium in a Little Guy since we don't have the big galley....now I am trying to figure out where to mount the converter where it's out of the way and safe from water....Any thoughts???

[toypusher]

I would use at least 12ga for that. What size wire came on the converter?? If it came with an installed cord, you should be able to cut the plug off and hard wire that cord into your outlet.

[Sonetpro]

You could go to a RV store. The one near me sells 30 amp cord by the foot. Or you could go to HD or Lowes, They sell bulk cord by the foot also. Tell them you need 30 amp.
Considering where you are at now, You are soon to find out the instructions that came with the WFCO is written by a chinese monkey. So here is a schematic that me and cracker39 worked out.

[sandman]

Sonetpro,
Thank you for the diagram and advice.
The 12 volt wires coming out of the back of the unit seem excessively thick for just 12 volt appliances. Do I have to use equally thick wire going to all my appliances?

I won't be using a battery next week since the park has shore power. Does that change anything with your wiring diagram having the battery out of the loop?

[Alphacarina]

The marine shore power connectors are rated for 30 amps, as many boats use them to power some pretty healthy sized air conditioners and BIG battery chargers - Those connectors are really 'overkill' for a small tear which has no large loads. They're expensive too - The plug to fit your new socket will probably cost you $25 or so and I'll bet you paid nearly that for the socket

You'll never have any need for the 30 amps that you get with the 10 gauge wire designed for those connectors - Even a 12 gauge wire is way more than you will ever need, but since you have the big socket already in the wall, I would use a 12 gauge, since it will fit the terminals of the socket better than the smaller 14 or 16 gauge wires will

The 12 volt wires coming out of the converter should go to a pair of terminal blocks, one positive and one negative. The total power for everything is carried by those large wires, but the individual appliances can be connected to the terminal blocks with smaller wires, suitable for the power drawn by the individual appliances

Don

[TD4FREEW/CTD]

is this plug for 120v ac, or 12 v dc?

no matter what you do, your wires should always be sufficient for the overcurrent device you have protecting them from possible fire hazards. basically the 2 mains things you need to be careful of when doing electrical work are A: electric shock (duh), B: FIRE!

the maximum size wire you should ever need for a 30a outlet is 10ga. the exeption being if your wire run were so long that the voltage drop required a larger wire. in wiring a small trailer this should not be an issue.

a couple of simple formulas that are essential to doing safe and sound electrical work:

amps x volts = watts.
watts / volts = amps.

if you know the the rated wattage of your appliance you can easily determine what size wires you will need.

example: you have 10 lights that are rated @ 25 watts each. they are powered by a 12 volt system. 10x25 =250 watts. 250 watts / 12 volts =20.833 amps.

if we use NEC wiring standards we find (copper) wires are rated at:

14ga - 15 amps
12ga - 20 amps
10ga - 30 amps

that being said, it is easy to see that for our hypothetical scenario, a 10 gauge wire would be needed to supply our load. a general rule of thumb that i practice is to only load the wires to %80 capacity.

anywho, i hope i've not rambled too much.

[Sonetpro]

Sonetpro,
Thank you for the diagram and advice.
The 12 volt wires coming out of the back of the unit seem excessively thick for just 12 volt appliances. Do I have to use equally thick wire going to all my appliances?

I won't be using a battery next week since the park has shore power. Does that change anything with your wiring diagram having the battery out of the loop?

The red is the battery charge wire.

I used the green to a marine fuse block to run lights, stero and most of my 12V so I could fuse each circuit according to the wire size.

I used the yellow to go to the inverter.

I used the blue to go to 2 12V outlets.

White is ground.

As you can see all of mine are going to high loads. So yes I ran the same size as was coming out the back.

I don't think the converter will come on unless there is a battery in the loop. It is a 3 stage charger so unless it senses to battery voltage and powers accoringly. But I could be wrong, I have never tried it.

MAKE SURE you fuse it accoring to the smallest wire on the circuit.