Electrical Wiring Help

[autostaretx]

Originally Posted by WandoTales13

So far so good guys!!! I can’t believe everything is running and all the breakers are working!

Right now I have my positive DC load wire on the lower end of the 250amp breaker for the inverter with the battery connection. For my AC wires from the outlets, do I connect the negative to my shunt and the positive to the inverter side of the 250amp breaker (it will also have its own breaker as recommended)

I don't understand that last sentence *at all* ... please draw a drawing.

"AC wires from the outlets" are alternating current, correct?
Then they don't have "negative" nor "positive" wires.

If you mean the *DC feed* to the *inverter*, then the answer to your question is probably "yes".

--dick (a picture is worth a thousand words, and avoids spelling errors)

[calbiker]

Need to have the battery disconnect switch at the positive battery terminal, not the ground side. You usually want to disconnect the battery when working on the wiring, etc. If the ground is disconnected then the positive cables are still hot. A short to gnd and sparks will fly.

Originally Posted by autostaretx

?? "negative battery wire to the switch" ?? and ?? "prior to the shunt or after the shunt and before the dc fuse block" ??

The last drawing you posted was:



The first question is: what are you trying to disconnect via the switch?
(i'll assume it's to pull the battery out-of-circuit)

Most people (except MB's starter battery disconnect) put the switch on the positive cable to the battery bank.
But that's merely "convention", not really necessary. (it may be why the switch's plastic is colored Red).

If it were me, and i was going to switch Negative, i'd put it between the battery and the shunt.
That allows you to remove the shunt from the game in the highly unlikely case that *it* was having problems.
The switch's purpose is to remove (disconnect) the *battery* , not the "battery AND shunt".

At least, that's how'd i'd do it.

--dick

[autostaretx]

Originally Posted by calbiker

Need to have the battery disconnect switch at the positive battery terminal, not the ground side. You usually want to disconnect the battery when working on the wiring, etc. If the ground is disconnected then the positive cables are still hot. A short to gnd and sparks will fly.

If he is NOT connected to the Sprinter's electrical system (such as using the alternator as a charging source), then only disconnecting Negative should be adequate.
His drawings don't show an alternator connection (but it may have been mentioned in passing).

But, like you, i FAR prefer to disconnect the positive (if using a switch).

If working on the system, i tend to disconnect both (negative first, to avoid "tool accidents").

--dick (gotta run...)

[calbiker]

There's nothing wrong connecting house battery ground to chassis. The house battery is still isolated from the chassis battery. We connect ac ground to chassis for safety concerns. The same can be reasoned for 12V ground. Should the OP in the future want to charge with the alternator then it's a much simpler mod, especially if the battery disconnect switch is located at the negative battery terminal.

Comments regarding the drawing:
The fuse between the solar and controller does not function as a fuse. It can only be used as a switch.

There should be a neg busbar connected to the left side of the shunt.

Don't need GFCI receptacles as the inverter has GFI.

Originally Posted by autostaretx

If he is NOT connected to the Sprinter's electrical system (such as using the alternator as a charging source), then only disconnecting Negative should be adequate.
His drawings don't show an alternator connection (but it may have been mentioned in passing).

But, like you, i FAR prefer to disconnect the positive (if using a switch).

[autostaretx]

Hopefully addressing many of calbiker's concerns
(and drifting back to "as laid out" versus "schematic" drawing style)
The solar/controller "fuse" is really a circuit breaker (he cited his three breakers, i just used the (yeah, it's a) "fuse squiggle" when i drew it).

PrettySchemes.jpg

--dick
p.s. on the wisdom (or not) of connecting the house DC negative to vehicle frame/ground: other threads have nattered on about that... some folks do, some don't. On my own system i chose a negative-ground (well, more properly "common negative") controller so that i wouldn't have to worry if/when i did interconnect the two systems. At the moment, they happen to be separate (no alternator connection), but i will probably add such in the future.

I have had experience when a load (a laptop's DC-to-DC adapter) turned out to have a common positive, then a serial RS232 connection to a frame-grounded device. Thrilling things tried to happen (but my redundant 3 amp fuse saved everybody's bacon).
p.p.s. "common positive/negative": things like the solar controllers (or DC-to-DC converters) sometimes actually have all of (either) their positive OR negative screw terminals tied together internally by a bus-bar. They then do their "controlling" by switching the other polarity. The cheapest MPW flavors usually have a common positive. That means that the negatives have to be all separate ... no cheating of having the panel negative tied directly to the battery negative.

[WandoTales13]

Correct, I'm not connected to the sprinter's electrical system. I have the DC ground connected to the 5/16 stud and the manual says that is sufficient (pg. 4) My inverter is ground to the van chassis though. Would you recommend having two switches then (positive and negative)?

My negative loads are connected to the 5/16 stud too (pg. 4)

I want to put wires in the "AC out" side of my inverter. The positive wire will go to a 20amp circuit breaker and then connected to my outlets in series. Are the outlets connected to the battery through the inverter's positive cable to the 250amp, or do I need to connect the wire from the "AC out" to the top nut of the 150amp with the inverter? (pg.6) The reason why I ask is because the bottom nut with the battery is a point for positive DC loads (pg. 5).

manual: https://www.altestore.com/static/dat..._Manual_V2.pdf
my inverter: http://www.xantrex.com/power-product...eedom-hfs.aspx

[calbiker]

You want one battery disconnect switch, located on the positive side of the battery.

The 5/16 stud you mentioned is that chassis?

You realize the inverter has fairly large quiescent current (battery drain). May want to locate it where you have the capability to turn it off when not in use.

If you want to conserve power then a 12V tv is great. I have a Vizio tv that comes with a 12V power buick. I connect the tv directly to 12V. Your laptops can also be powered from a dc/dc converter (12V to 19V or whatever). That's a fairly significant power savings as you don't go from 12V to 120Vac and then to 19V.

[autostaretx]

Qualifying preamble: I had lost track of what "page 4" was referring to, until i got to the bottom (while writing this ramble) where you helpfully (re)provided the link.
THAT MNDC PANEL IS FOR HOUSE-ROOF-SIZED SYSTEMS.
The grounding connections (etc) shown on page 4 are WITH THAT IN MIND.
It's for such contingencies as lightning strikes, and the fact that HOUSE systems can have much higher voltages (and currents) than you'll be dealing with.
(((i had mistakenly thought that "page 4" was in the Inverter manual)))

Typical RV systems do not have to "ground" the panel negative.
You should read your PANEL's instructions to see what THEY recommend (they may want the panel frame tied to a specific polarity, to deal with wind- and capacitively- induced surface charge on the panels)

The MNDC page 4 also shows a GFCI breaker on the solar panel feed ... the right-most small (5A) breaker with the little green zig-zag component (a resistor) across it ... it's mechanically coupled to the 63 amp breaker next to it, which would trip out the panel feed to the controller. Your panels wouldn't generate enough current to trip that.
That's merely an example of how far your intended use of the MNDC box differs from the goal of the page 4 diagram.

... the following was written before realizing that the above preamble was needed:

Originally Posted by WandoTales13

Correct, I'm not connected to the sprinter's electrical system. I have the DC ground connected to the 5/16 stud and the manual says that is sufficient (pg. 4)

Confusion rains and reigns again: when you mean "my DC negative" please say that rather than "ground" (since you are also connecting AC and shore-power green-wire ground).

My inverter is ground to the van chassis though.

See? That ground is the external metal box, and truly means "earth ground" (since it's part of the green-wire connection in your shore power). If you probe the inverter when it's just sitting disconnected on your dining room table, you'd (99.9% certain) discover that that "ground" is totally isolated from the other six terminals (DC+, DC-, AC hot in, AC neutral in, AC hot out, AC neutral out). The "ground" will connect to the 3rd pin on the AC connections.

Would you recommend having two switches then (positive and negative)?

... there's "recommends" and there's "suggests" (along with "hints" and "nudges" and "shouts"). Minnesotans add in "could". "Practicalities" come in from the side to muddy the waters.

(a) I don't necessarily "recommend" disconnecting both sides of the battery, but you certainly could.
Simply disconnecting one side is "enough" from an electronics point of view: you have interrupted the current path battery-wire-load-wire-battery.

(b) if i was trying to disconnect both sides, i'd "recommend" ("practicalities" allowing) a double-pole switch, so you only have to flip ONE handle to achieve the full disconnect. Having two separate switches is an invitation to only flipping one, and discovering (the hard way) that you should've flipped both (or even simply "the other one").

(c) if i was building your system, i'd probably just use one switch in the positive feed, as CalBiker suggested, and as per my last drawing.
AND:

My negative loads are connected to the 5/16 stud too (pg. 4)

Since you ARE thus tying your "house" system to the Sprinter's frame, putting only one switch in the negative may lead to "issues" (mainly since you have other current/voltage sources involved (solar and inverter).
(BUT: (engineering speak here:) from purely the battery's point of view disconnecting only the negative DOES take them out of the game... if there's no way for current to reach the battery's negative post(s), the house batteries will NOT be "in-circuit".)

That said, you (for example) haven't shown how the shunt sensor is powered (some shunt assemblies include a small circuit card that has its own private two-thin-wire feed... how is that powered? does it provide a sneaky "back door" to the (theoretically) disconnected battery?. Again: if the ONLY connection on the house battery's post is to the Big Switch, and then the Big Switch is what feeds the shunt, the Big Switch will indeed remove the house batteries from the game.
By having the house negative bar tied to the Sprinter Frame, you *are* still providing possible pathways for the Sprinter's Starter battery to cause confusion (if a (let's say wrench) tool accidentally bridges a vehicle positive to the house system's wiring).

note: here is when i woke up to the need to write the "preamble" (far above).

I want to put wires in the "AC out" side of my inverter.

Yes.

The positive wire will go to a 20amp circuit breaker

AC wires do NOT have a "positive" ... they have a "hot" (or "line") and a "neutral" (or "return").
do not use the word "positive" when referring to AC.
(and it doesn't hurt to say it as "110v AC" to doubly-verify that's what you're talking about)

and then connected to my outlets in series PARALLEL.

...

Are the outlets connected to the battery through the inverter's positive cable to the 250amp, or do I need to connect the wire from the "AC out" to the top nut of the 150amp with the inverter? (pg.6) The reason why I ask is because the bottom nut with the battery is a point for positive DC loads (pg. 5).

Again, you've lost me with the above ... the inverter should be totally isolating your 110 vac outlets and wiring from the DC side of things.

--dick

manual: https://www.altestore.com/static/dat..._Manual_V2.pdf
my inverter: http://www.xantrex.com/power-product...eedom-hfs.aspx

[WandoTales13]

Originally Posted by HarryN

Usually the GFCI plugs are wired in series and one plug will protect all of the others downstream.

I thought it was series…

Originally Posted by calbiker

You want one battery disconnect switch, located on the positive side of the battery.

The 5/16 stud you mentioned is that chassis?

You realize the inverter has fairly large quiescent current (battery drain). May want to locate it where you have the capability to turn it off when not in use.

If you want to conserve power then a 12V tv is great. I have a Vizio tv that comes with a 12V power buick. I connect the tv directly to 12V. Your laptops can also be powered from a dc/dc converter (12V to 19V or whatever). That's a fairly significant power savings as you don't go from 12V to 120Vac and then to 19V.

5/16 stud is a stud in the MNDC. I have a 250amp circuit breaker between inverter and battery. During my trial runs, turning the circuit breaker off cut the power to the inverter. Is that what you mean by a switch?

Oh awesome, I'll definitely look into those thank you so much

[autostaretx]

Originally Posted by WandoTales13

I thought it was series…

All of the "slaved" outlets are in parallel.

You didn't mention GFCI in the note i was commenting upon.

The slave outlets consider the GFCi-equipped outlet as a "device" (think "circuit breaker")

We're running into the ambiguity of English trying to describe a complicated circuit.
(you could safely say "downstream from the GFCI" instead of "in series")

If you carefully squint at message #55 you won't see the word "series".

--dick