Epever 40 amp mppt delivered

there is a reason for stick house solar positive ground

the earth is 'positive charge' during an electrical thunder storm
the sky is 'negative charge'

this why they use a positive for common and ground it out to earth ground

while it appears that lighting strikes down from the sky
the spark actually jumps up from the earth to sky

it is invisible until it meets the sky
then the ionization trail travels the reverse course lighting up the sky
making it appear that bolts strike down

this is all non-relevant in an RV situation, where the positive common (of the solar) is NOT bonded to rv frame ground

using the word 'ground' in an rv solar install, confuses the issue
as everybody thinks of RV/vehicle ground as the frame which is bonded to the battery negative

The Tracer manual says, "The Tracer-A series is a positive ground controller. Any positive connection of solar, load or battery can be earth grounded as required."

Earth grounded is not what happens in an RV installation.

My old PWM controller manual has " a common positive ground" and the diagram on page 6 here shows to "ground" the positive battery post if you do. In fact, I had the usual battery negative "ground" to the RV frame and the controller's output to battery pos and neg as usual, and it all worked no problem. (I had the plain version not the R one , but all same really)

http://www.epsolarpv.com/en/uploads/news/201310/1382336207652695.pdf

mike-s wrote:

MrWizard wrote:
here we go again

its NOT positive ground

it IS positive COMMON

Which are exactly the same thing. In electrical circuits, "ground" is the common reference point. For controllers which tie all the positive terminals together, that's a positive ground. RVs which tie devices to a frame connected to battery -, that's negative ground. The two don't work well together, which is the whole problem.

NO by that description
a positive buss bar with batteries and solar controller and converter
would be called ground

and it is NOT

use the load terminals for timed circuits like designed, infinite timed combinations. I like on at dusk for 3hrs with dusk defined @7v, one or 2 1w led landscape lights let you see in the dark!

BFL13 wrote:

mike-s wrote:

MrWizard wrote:
here we go again

its NOT positive ground

it IS positive COMMON

Which are exactly the same thing. In electrical circuits, "ground" is the common reference point. For controllers which tie all the positive terminals together, that's a positive ground. RVs which tie devices to a frame connected to battery -, that's negative ground. The two don't work well together, which is the whole problem.

Nope. I have had a number of different solar controllers, some of which have said in their manuals that they have a "positive ground".

Every one of them worked just fine in the RV whether pos or neg ground internally. Every one had its neg to the Trimetric shunt neg and all was good.

You could cut it short and admit you don't understand electrical circuits. But no, you want to dig the hole deeper. No one said the mismatch couldn't be made to work if you don't try using the load control circuit with negative grounded equipment. The saving grace is that the panels themselves are typically not connected to frame ground in the power circuit. You're kludging it by ignoring the built-in load monitoring of the controller and buying an external Trimetric monitor instead.

But, it's still wrong to claim, as you have, that there's a difference between "ground" and "common" for RV circuits. In household AC circuits, the difference is in which wires carry current and which are protective. For RV DC circuits, they're the same, there is no separation between ground and neutral.

mike-s wrote:

MrWizard wrote:
here we go again

its NOT positive ground

it IS positive COMMON

Which are exactly the same thing. In electrical circuits, "ground" is the common reference point. For controllers which tie all the positive terminals together, that's a positive ground. RVs which tie devices to a frame connected to battery -, that's negative ground. The two don't work well together, which is the whole problem.

Nope. I have had a number of different solar controllers, some of which have said in their manuals that they have a "positive ground".

Every one of them worked just fine in the RV whether pos or neg ground internally. Every one had its neg to the Trimetric shunt neg and all was good.

MrWizard wrote:
here we go again

its NOT positive ground

it IS positive COMMON

Which are exactly the same thing. In electrical circuits, "ground" is the common reference point. For controllers which tie all the positive terminals together, that's a positive ground. RVs which tie devices to a frame connected to battery -, that's negative ground. The two don't work well together, which is the whole problem.

I put my Tracer neg output to the Trimetric shunt same as with the other negs. The Trimetric AH counter needs that to get the totals right.

I doesn't matter if the controller is "positive grounded" since you do not "ground" the panels on the RV frame, and you do not "ground" the controller to the RV frame. It is an RV not a stick house.

here we go again

its NOT positive ground

it IS positive COMMON

meaning the panel positive, battery positive, load positive
are connected in the controller

charge control is done by switching the Negative side, load on/off is done by switching the Negative

you are not going the short positive and negative, no matter what you do with the shunt

you can probably put the shut in the positive cable if you wish
just reverse the (2) connections for senseing so it counts in the right direction

in many cases with many instruments, shunts do not have to go in the negative, external shunts can go in either line in most cases

convention has been to put them in negative / ground side

lawrosa wrote:

...
2. But then the question is the solar. Its a positive ground controller. So to run the solar to the shunt would mean I am tieing the solar neg to ground.
...

My understanding is that the pos ground only applies to the "load" terminals of the Epsolar Tracer

So your graph looks ok to me.