High Performance Power and Grounding

[Nessism]

Ed,
The proposed approach is not so much for redundancy as for separation of current flows ala "single point grounding". Here is a reference that provides some introductory background information.

http://www.ese.upenn.edu/rca/instruments/misctutorials/Ground/grd.html

In effect the ground point is the most physical location in the circuit that has the lowest DC voltage (ignoring the stator and R/R internals).

See my comments on case common grounds for power device packages.
Jim

Guess I'm an electrical simpleton; in my view if the R/R ground wire is run over to the battery post, which in part has a thick battery cable running directly to the engine/frame, then running a an additional wire from the R/R to the frame is somewhat redundant. Don't take me wrong, I've done just that on both of my bikes, it's just that I don't think it's necessary if all the connections are clean and properly grounded.

[posplayr]

I've done just that on both of my bikes, it's just that I don't think it's necessary if all the connections are clean and properly grounded.

Ed,
The point is that connections do degrade and so with the separation of grounds you are in a much better position to maintain your charging system performance.

In the example I provided, a paltry 0.1 ohms is all it takes (in current path from R/R (+) to fusebox, to all connections and finally back to R/R(-) ) with 13 amp of current flow makes the charging system marginal.
Jim

[posplayr]

in my view if the R/R ground wire is run over to the battery post, which in part has a thick battery cable running directly to the engine/frame, then running a an additional wire from the R/R to the frame is somewhat redundant. .

Ed
I reread your post.

Think about how any frame grounded loads (like a blinker) return current back to the R/R (-):

• The current flows through the blinker which is grounded to the forks.
• The current travels through the head set bearing to the frame.
• The current now travels through the engine mounting bolts from frame to the case.
• The case current travels along the large ground lead to the negative side of the battery.
• Now the current flows (not to the battery) but to the R/R (-) to complete the circuit.

All electrical loads which are grounded to the frame return current to the R/R (-) in this way.

So the added wire that runs between battery and R/R (-) is carrying not only 2-3 amps of charging current but also what ever current is being returned through the frame. The more current that flow through this wire the worse any resistance will cause a voltage drop.


Look closely at the picture below. It is of the two charred ring lug ground wires mentioned earlier. This wire is carrying quite a bit of current (10 amps) to burn all of the insulation off. The current flow was between two supposed ground points. Normally the one ring lug is frame mounted under the front battery box bolt. The other is connected to the electronics side plate where the R/R, solenoid and fuse box are mounted. I checked the damage to the harness itself and the current was not flowing through the harness but between the grounds. Since one side is connected to the R/R (-) we have to assume that the effect here is from all of the current that is frame returned. This might have been exacerbated by an over charging condition, but even dropping from 17V to 14.5V at the battery there is still a bunch of current flow here. Maybe the igniter is shunting the coil primary current to ground???

Without this direct wire, all of this current is daisy chaining from frame, to case to battery - lead to the R/R (-) through the added battery ground. All this current is cause any resistance to produce a voltage drop.

I hope this helps. When doing power and grounding you have to look at physically where the currents are flowing.

Jim

[mustangflyr]

My 2 cents

An interesting post, don't always understand everything I know about electrics but I muddle through. What I did with my GS1000 is to put between the battery + and the fuse panel a relay controlled by the orange wire from the ignition switch, the fuses are cold until the key is turned on. also all connectors were cleaned or replaced and I installed relays to control the headlight and the horns, coils soon. So far according to the Stator Papers the volts are happy and the connectors stay cool to the touch and the smoke stays inside the wires as it should. After a few hundred miles so far so good. To diagnose electrical systems always make sure to have a fully charged battery.

[Nessism]

Jim,
I think the main problem with Suzuki's GS wiring standard, as it applies to the charging system anyway, is the R/R is commonly grounded to the rubber mounted battery box/electrical panel, and the only metal providing the ground path is the small cylindrical bushing going though the center of the rubber grommets - both of my old 550's and my 850 are this way. These metal bushings typically are pressing on painted metal as well which acts as an insulator. By extending the R/R ground wire from the original location over to the battery, about 90% of the improvement in the ground path occurs since the battery itself is grounded with a thick battery cable that is pretty robust. I'm in favor of the extra R/R ground to the frame but again, I think this is somewhat redundant now that the R/R is grounded to the battery.

[posplayr]

What I did with my GS1000 is to put between the battery + and the fuse panel a relay controlled by the orange wire from the ignition switch, the fuses are cold until the key is turned on. .

This removes the ignition switch from the current path to the fusebox.

[mustangflyr]

Electrics

In addition to my previous post I changed to a blade type fuse box and relocated the R/R to a front frame tube under the steering head where it stays cooler. So far works great.

[Charlie G]

Jim,

Help claitify for a Carpenter who really only know that, ground is where my nails fall.

1-Impedence, restiance and Ohms are one in the same? Right?

2- The term "shunt" refers to an additional ground?

Thanks!

cg

[bonanzadave]

Looks good to me except I dont like that crappy wire and those CS (chicken sh!t) plastic terminals. Airplane wire and terminals have me spoiled.

[posplayr]

Jim,

Help claitify for a Carpenter who really only know that, ground is where my nails fall.

1-Impedence, restiance and Ohms are one in the same? Right?

2- The term "shunt" refers to an additional ground?

Thanks!

cg

Charlie,

Right on #1; in this context they are all the same. Impedance is a generalizaton of resistance (which is DC) which encompases AC resistance (which includes reactance). Ohms is a measure of both.

On #2 there are typically two types of regulators Shunt and Series.

A Series regulator carries all the supply current. The OEM R/R does as well but, I'm mainly referring to the regulating device in the second stage of the R/R. That device is shunt because it operates by diverting current from the load back to the source without ever carrying all of the load current.

I'm realizing this probably doesn't explain anything and so I'm really wondering what the significance of the Shunt v.s. Series distinction is in this context? Wow I'm pressed to make a distinction.

I think that the derogatory insinuation is that shunt is not as good as something else. I'm not sure that series would be any better. The issue is really being able to control the battery voltage by direct measurement of the load v.s. relying on the terminal voltage of the regulator.

Series regulators normaly control by monitoring the output voltage which is after the voltage drops of the series regulator. Shunt suggests operating off the terminal only (as the OEM does).

I'll check with my experts tomorrow to see if there is anything I missed or have wrong.

Jim