TrueCharge 2 install

[hump180]

Hey everyone, I am in the process of installing my Truecharge 2 and have a question about grounding for the more seasoned electricians here. I removed my promariner (heavy) from under the port lazarette and have decided to mount the new charger in the forward port side setee just forward of the holding tank. I pulled the positives through and forward to the new location. The ground wire was attached to the transmission and I need to get a longer wire to reach the new position. The only issue I am having is that there are two grounding posts on the truecharge 2. According to the manual, one goes to the DC negative bus and the other is outside the charger case and is for grounding the case which is recommended in the manual. Is it necessary to ground the case? I wold rather install the same way as my old one, but I do not want it to be unsafe.

[Ted Pounds]

I don't think it's necessary to ground the case, but it can't hurt.  As I recall there is a green wire for the AC ground at the AC hookup and that that should cover for the case.  As for the ground to the DC negative bus I wouldn't go all the way back to the transmission.  Just go to the DC ground bus behind the electrical panel.  It'll be a lot less work snaking wires. 

[hump180]

Thanks Ted. As for the negative bus, it is full, so I would either have to add another bus or just feed the cable to the trans. Probably go with the latter to save time. 

[Stu Jackson]

NOOOOO!

Don't mix up the AC and DC grounds, PLEEEZE.

Most electrical books recommend that you ground the AC to the engine.  As far as I know, and from earlier discussions about C34 wiring, I do not believe the AC was grounded to the engine (boat ground) on our boats by the factory.

Just tie the case ground into the AC green ground wire and you're done.

This is what I did with our Freedom 15 inverter charger in 1998 and it's been working fine for 10 years.

[hump180]

Stu, I have been going over the manual to make sure I read it correct. The external stud on the truecharge 2 is the "DC Chassis Ground."
The manual says: "Xantrax recommends that you install a DC chassis ground (earth) from the ground stud on the truecharge 2, to the engine bus or DC ground bus." So they intend for us to have a DC negative from the charger side negative post, along with an additional DC ground from the chassis stud. I was just hoping that I could exclude the chassis ground. Maybe this is some new type of setup to protect the system or the charger?? Here is a link to the manual and page numbers http://www.xantrex.com/web/id/2438/docserve.aspx      2-19, 2-23



Bill

[Stu Jackson]

Yes, Bill, that's right, it is a DC chassis ground, also mentioned in item 5 on page 2-22.  It is NOT an AC ground, which I might have incorrectly read into or thought was your first question.

So, just wire it up the way it's drawn on page 2-19, because item 15 is a DC chassis ground.  Forget about how your old unit was wired, this one's the new one and follow the directions.

You can go to your engine or to the DC buss at the panel.  I'm not sure why you say it's full because some boats have not only the DC negative buss on the back of the electrical panel itself but an additional isolated terminal strip glued to the inside of the hull (NOT the AC strips).  Your choice.

The AC is completely separated and has nothing to do with this at all.  AC power lines are L, N and G.

Thanks for the manual, a picture is worth a thousand (possibly incorrect) assumptions.

[jmnpe]

Hi Bill,

The chassis ground is only there to provide some additional protection for 2 things: potential Radio Frequency Interference from the high frequency switching power supply circuits, and extra protection to prevent the charger case from becoming "hot" with 120 VAC if there is some sort of internal circuit failure that could result in the LINE AC input shorting to the case. In many boats, the AC Green wire ( AC gnd and bonding ) will be connected at a single point to the DC ground circuit in the boat. In the case of the C34, I don't know if that is the case. As Stu indicated early on, connect the chassis ground to the AC ground: that way, if the case becomes "hot", the AC CB feeding the charger will blow and eliminate the potentially lethal AC voltages on the charger chassis. This chassis ground wire doesn't need to be any larger than the AC power  input feed wire sizes.

Unless you have a very low output Truecharge2, don't connect the DC ground from the charger to the DC ground behind the distribution panel: the stock boat wiring has only a 10 gauge wire from the battery grounds under the starboard settee over to the DC ground terminal strip behind the distribution panel. Even at 20 amps, the voltage drop through the 10 gauge wire back to the batteries will have a noticeable negative effect on the speed at which you will be able to recharge you discharged batteries. Follow the wire size guidelines provided in the Truecharge2 Manual for connections of the charger outputs and DC ground using the distances from the charger all the way to the batteries.  The Truecharge2 can be a very capable charger when properly sized for your battery bank and properly installed.

Regards,

John
C34 Otra Vez
Standard rig
1988 Hull 728

[hump180]

John,  I went with your suggestion and used the AC ground as the case ground. I ran the other DC negative back to the transmission as origanally set up. I fred up the charger and it worked as planned. My batteries were a;ready charged and the charger was chargeing at the less than 5 amp setting as intended and doing it silently. Seems a good setup.

[Stu Jackson]

I ran the other DC negative back to the transmission...

Good work, Bill.  By transmission, do you mean the bell housing, where the OEM engine ground is connected to the engine to one of the capscrew(s)? [Part #8 on the diagram].  See:  http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&page_ident=200142-53&model=M-25%20/%20M-25XP%20/%20M-25XPA&manufacturer=Universal&title=Bell%20Housing%20Group%20/%20Transmission&quant_position=&catalog=200142&printparts=200142&printservice=200151&printoperators=200157&comment1=

[Ron Hill]

Bill : I would have routed the negative ground from the chargers charging circuit to the furthest negative post on the furtherest battery from the charger.  I believe that would have given you the best charging circuit for the batteries. 
I would have used the same size wire as you did for the (+) positive wires.  A thought

[hump180]

Thanks Stu, I did mean the bell housing and it looks like it may have been the #8 from the diagram.

Ron, I probably should have ran it to the battery post and the manual does specify that. I had just figured that I would wire the ground similar to the last charger and as long as it was a solid ground with a good connection it should be OK. I will condsider your suggestion though and it would probably only take a few minutes to reroute and reterminate it at the battery post.

I guess I have not followed the directions for the truecharge 2 to a tee, especially in regards to combining the case ground stud in with the AC green. But after Stu and Johns suggestions and thinking about it for a while I am very confident that it was a good solution. Overall everything turned out very clean and I am hoping to post a picture tomorrow of the final wiring and mounting.

[hump180]

Here are the pics of the final install. I just drilled some pilot holes into the bulkhead and used some stainless metal screws to attach it. I used some small rubber grommets on the bulkhead side of the charger screws to isolate some of the hull vibration. The wires were pulled from the old charger location under the port lazarette and routed under the floor and through the waste tank compartment and finally pulled through a 1" hole I made with a hole saw in the forward port setee compartment as shown. In the last pic you can see the jumper for the AC ground (green) to the case ground stud as suggested by Stu and John but executed with my full responsibilty.

[dbpaul]

When installed my Truecharge 20 I called Xantrex about the ground wire and they said run to engine or battery ground.
Here is how I did it......

http://picasaweb.google.com/1dbpaul/DcGround?authkey=Gv1sRgCJyl-aPb9PqAOA#5319419516234659842




paulj












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