Solve Driveway Camping GFI Problems by Splitting the Neutral

An RV of decent size expects a 4 slot, 50 amp power cable which provides two 50 amp circuits.  When driveway camping, most hosts don’t have a 50 amp power connection, so if two circuits are desired (for running two air conditioners, for example) a splitter like this can be used along with a 30 amp to 20 amp adapter to present two 20 amp plugs that can be plugged into two different circuits in the house:


The problem is that most household outdoor plugs have a GFCI in the circuit that looks like this:


The GFCI protects homeowners from shock by insuring that the same amount of current flows back into the neutral return wire as flowed out from the hot wire.  If not, it means some of that current is flowing elsewhere, like through a person.  When this current imbalance is detected, the GFCI “trips”, and needs to be reset.

Since the RV power system has in its four connector jack two hot lines but only one neutral, using the splitter above won’t work if either 20 amp plug is connected to a GFCI-protected circuit, since the current returning from the two hot lines spills into a common neutral, and is then split by the splitter.  Since the current has been “mixed” on the common neutral, the returning current on the then-split neutral will never exactly match the inbound current from the corresponding hot line, so the GFCI will trip.  It’s like two parallel rivers: the inflow and outflow on a given river is identical, but if a trench is cut to connect the two rivers, the inflow and outflow on each river won’t match since one river donated a bit of its inflow to the other river’s outflow through the trench.

The solution is to split the neutral, so that each of the RV’s two circuits is completely separated from the other.  Here’s the common, single neutral bar in the RV’s breaker box:


I removed the neutral bar and installed two separate neutral bars:


Since the neutral from the RV’s four pin connector now only serves the right side of the breaker box, I brought an extension cord in, cut off the female end, and wired it in on the left side of the breaker box to supply power for the left side.  I did the same thing on the right side too, so the right side can receive power from the big 50 amp connector on the back of the RV or through its new 20 amp extension cord.  The right side can also receive power from the inverter I wired in a while back, so the three breakers that can provide power have been colored to insure I only turn one on at a time.  I also added a second meter so I can repay our hosts for the power used on both circuits:


The new pair of 20 amp power cords come out through the bottom of a compartment.  In the plastic tub they’re plugged into a pair of extension cords that lead to the house:


Until now, the common neutral problem has limited us to one 20 amp circuit when driveway camping, which can be uncomfortable in hot weather since an RV this large needs both air conditioners to keep it cool.  I’m happy to have finally broken free of this limitation!

Day 760: Cape Breton Island to Moncton, Nova Scotia

Shabbos in Sydney, Nova Scotia, was nice, with perfect weather.  I’m so glad to see the beginnings of Autumn.

Today we said goodbye to Cape Breton Island and drove east to refill our water in Amherst, Nova Scotia.  Last time we used a water bandit to mate our garden hose to the supply hose at the water station, which worked but we ended up soaking wet since the supply hose put out more water than the garden hose could handle.  This time we had the supply hose pour into a garbage can, then used the transfer pump we usually use with our 45 gallon water bag to pump the water from the garbage can into the RV:



Just in time for leaving Nova Scotia (New Scotland), Trish finished her Scottish-craft Rug Hooking pillow project:


We drove about 300 miles today to overnight at the casino in Moncton, New Brunswick, which we last visited a few weeks ago.  See the trip map for today’s drive and our current location.

Day 744: Fundy National Park

Unlike their US counterparts, Canadian Walmarts have WiFi, which is great.  At the Walmart, we bought a Chatr SIM card for our unlocked phone.  $60 Canadian (about $45 US) buys unlimited in-Canada calling and 2GB of data for a month.  Like the last time we visited Canada, I used a free Canadian DID from and a free account to route inbound and outbound US calls through a Canadian phone number to avoid Chatr’s $0.20 a minute international call fee.  As far as Chatr is concerned, it’s a free domestic Canadian call, and I pay fifteen-hundredths of a cent per minute to for making the Canada to US portion of the call.  Not too shabby!  See the link above for diagrams and more geek-talk.

Today we drove east to Fundy National Park, which preserves one of the last Acadian forests in New Brunswick:


We hiked the Caribou Plain trail.  The trail leads to a viewpoint overlooking a bog.  The bog here is about 12 feet thick, with successive layers of sphagnum moss growing on top of each other, leaving older layers below to accumulate as undecayed peat.  At this viewpoint, the peat pile is so thick that the pile slumped as it slid downhill, leaving a water-filled depression called a flark:




The kids dropped sticks and rocks into the flark to test its quicksand-like characteristics.  From time to time, moose become mired in the flark and die if not rescued in time:










After finishing the hike, we continued east.  We ran into road work, which reminded us of Alaska:


We reached the visitor center for the park:


The kids completed their Parks Canada Xplorers workbooks and received their dog tags:



We went for a hike on the Dickson Falls trail:



Silver Falls it ain’t, but it was still pretty:


We drove down to the shore of the Bay of Fundy:


Leaving the park, we continued east and happened upon this lovely turnoff with access to the bay:



This is the first sandy beach we’ve seen on the Bay of Fundy:






We were chased off the beach by a thunderstorm, so we continued east and north to Moncton, New Brunswick.  The plan was to spend Shabbos with the Jewish community here, but the parking didn’t work out so we drove to the other side of town where we will be parked at the Casino New Brunswick.

Good Shabbos from Moncton, New Brunswick!  See the trip map for today’s drive and our current location.