Installing a WFCO Power Center in a Skoolie

Disclaimer!

While I was successful installing a WFCO 8955 Power Center in a skoolie, I am not an electrician!  Don’t take my word for anything in this article but use it as an addendum to your own research.  My only claim to competency is that A) I didn’t electrocute myself, B) I didn’t set anything on fire and C) it works!

I learned a lot from this book when I built my house. I highly recommend reading it before tackling any electrical job!

Electricity Basics

I’m not going to really cover them in this post.  I DO have a plan to write one in the future that covers my research and will be geared toward helping skoolie converters just getting started with electrical stuff.  But that’s beyond the scope of this post.

Indispensable Electricity Basics Critical to this Post

However, there are some key concepts to understand in order for this post to make sense.

AC and DC

AC

I wanted AC power on the bus.  AC is (approximately) 110 volt power commonly accessed in homes when you plug in the blender.  Or other common electrical appliances.  

Now we’re not big into electrical appliances.  We won’t have a big screen TV, an air conditioner, a washer/dryer or a turnip twaddler.  However, I would like to be able to charge the cameras and laptop, and whip up a frozen margarita from time to time.  

DC

There will be times when we’re off-grid, however, and we’ll rely on battery power.  Thus most of our electrical needs, like lights and the water pump can be met through 12 Volt power.

We need a system that interfaces both AC and DC power; thus, we settled on the WFCO Power Center.

WFCO Power Center Features

The WFCO Power Center provides fuses and termination points for eleven 12 volt electrical circuits.  Moreover, each circuit has a little red light that comes on if the fuse blows so that you don’t have to remove the fuse, find your glasses and hold it up to a bright light to figure out why the water pump doesn’t work.

Also, a converter magically converts AC power to DC power trickle charging your batteries while plugged in to a 110 Volt shore power source.

Finally, the WFCO Power Center provides a circuit breaker panel to install (purchases separately) 110 Volt circuit breakers.  To these breakers you run your AC circuit lines.

I also found the WFCO Power Center reasonably priced!

Wiring the Bus

Stranded vs Solid Wire

A more detailed post on bus wiring will be forthcoming.  Know for now, though, that I ran 110 Volt circuits with 12 gauge stranded wire in conduit.  

While debate rages out there like a swirling dervish about whether or not stranded wire is worth the extra cost, I decided it was.  I mean, if you want to experiment, take a section of solid wire, grab the end of it with needle nose plyers and bend it back and forth.  Like the “how many licks does it take to get to the center of a lollipop,” you can count the bends before the wire breaks.  (I’d say less than 10!)  

Stranded wire, however, you can bend many more times before damaging it.  

I don’t know about your bus, but mine vibrates when it runs.  And I don’t want to have to tear into walls to try and locate a broken wire.  I went with the good stuff.

Conduit

I also decided to run wire inside conduit.  I did this because most sites I researched said that stranded wire should be run in conduit.  

I also did it because I know that at some point I’m going to wage war with mice in the bus.  There might not be a battalion of them if I’m careful (and a bit lucky).  But campgrounds and campers are a haven for the little rascals and I’m not naive enough to think they’ll never appear.  Like the solid wire situation, I don’t want to have to tear apart a wall to find a chewed wire.  The more I can protect the little darlin’s (wires, not the mice) the more they’ll take care of me.

So I ran conduit.

I pulled all my circuit ends into an electrical closet where I hung my power center.

Building the WFCO Power Center Cabinet

I needed a way to mount the WFCO power center to the wall, so I built a little cabinet.  Using some scrap plywood for the bottom, some 3/4 inch stock and my Kreg Jig, I framed out a platform with a frame, then painted it black.  

Why did I paint it black?  I don’t know…walls where electrical panels are always painted black.

I nestled the WFCO Power Center right in there and secured it with some screws.

Wiring the WFCO Power Center

110 Volt Circuits

Securing Wire and Conduit to the WFOC Power Center

I began by connecting my 110 Volt conduit runs to the panel using service entrance connectors.  Once I had secured the conduit to the WFCO Power Center, I trimmed the wires, cut off the insulation, then stripped a half inch off the power, neutral and ground wires.

Next, I connected the neutral (white) wires of each circuit to the neutral bus bar at the top of the power center.  Then connected the ground (green) wires to the ground bus bar at the left of the power center.

Finally, I connected the hot (black) wire to the 110 volt circuit breakers, and snapped them in place.  I used a 30 amp breaker as the main, and 20 Amp breakers for the rest.

Installing the 30 Amp Twist Lock Inlet

Using a hole saw, I drilled a hole through the exterior wall of the bus.  I placed the inlet into the hole, marked the place of the screw holes to hold it in place, pulled out the inlet and pre drilled for the screws.  

The back side of the 30 Amp Twist Lock Inlet has a collar that needs to be unscrewed to fit wires through.  Unscrew the collar, insert the wires, then loosen the screws that hold the neutral, ground and hot wires into place.  Insert the wires (having stripped a 1/2 ” of insulation from the ends, tighten the screws, then tighten the collar.  I then put some silicone caulking over the screw holes, and screwed the inlet to the side of the bus.

Wiring the Twist Lock Inlet

I ran the neutral, ground and hot wires through a squeeze connector and into the WFCO Power Center.  I connected the neutral wire to the neutral bus bar at the top, and the ground wire to the ground bus bar on the left.

Next, I connected the hot wire to the back of the main breaker switch.

12 Volt Connections in the WFCO Power Center

Like the 110 Volt circuits, I ran the 12 Volt circuits through conduit and tied them into the Power Center knockouts using connectors.  Once inside the power center, it was easy to screw each wire(after trimming and stripping the insulation)  into the lugs on the right side. 

Most of the 12 volt wire I repurposed from the deconstruction phase. You can read about how to remove the uncessary wiring without disabling your bus here. 

Adding Fuses to the WFCO Power Center

To energize the circuits, I needed to add 12 volt blade fuses that are NOT included with the power center.  To determine what size fuse I needed, I checked the draw from each circuit.  

Most electrical appliances measure power draw in Watts.  To calculate Amps, divide the total watt usage by the volts.

For example, one of my light circuits has 7 LED lights on it which draw 3 watts each for a total of 21 watts.  21 divided by 12 volts equal 1.75 Amps.  

I found some discrepancy out there researching fuse size.  Some sources say multiply your Amps by 125%, others say 150%.  However, in my case it didn’t make much difference.  1.75 Amps X 1.25 = 2.18 fuse rating and 1.75 X 1.5 = 2.6.  In either case, I wanted to round up to the nearest fuse size which is a 5 Amp fuse.

Wiring the Battery to the WFCO Power Center

First I needed to calculate the size of wire that I needed.  In checking the chart here I did some calculations.  The WFCO 8955 Power Center has a DC rating of 55 Amps.  Since my battery is less than 4 feet from the converter, the chart recommends a 6 gauge wire.  

I stripped the insulation from both ends of the negative and positive wires, crimped lugs on the battery end of the wires, then ran the wires through a service panel connector and into the WFCO 8955 Power Center.  I hooked the positive end to the lug at the bottom of the power center on the right hand DC side and the negative end at the top.

Fire that Puppy Up!

For my house and for many situations I knew I would be in, so I bought this 20 to 30 Amp 90-Degree RV Shore Power adapter.  I like the fact that it has the 90-degree turn in it to lessen the stress on the cord.  It also screws in for additional security.

So I plugged everything in.

Always a moment for suspense”¦.

I heard the Power Center fan kick on for a moment then stop.  

This made me nervous.  

But…that’s what it does!  It only really runs if it’s super hot, which hasn’t really happened.  All my DC and AC circuits work, the WFCO Power Center keeps my deep cycle battery charged and I can run the blender!

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