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24->12 inverter wiring

Posted: Tue Jul 30, 2013 6:32 pm
by stark311
I've searched and searched on here to find a how-to for hooking up an inverter. Can anyone point me to the thread? Can't imagine it hasn't been covered...

Re: 24->12 inverter wiring

Posted: Tue Jul 30, 2013 7:36 pm
by pcolette
The wiring is usually brand/model specific and is best obtained from the manufacturer. For instance, some models are ground isolated while others are not and each would need a different method of grounding for proper operation.

Here's a wiring diagram from a SurePower unit:
Untitled.jpg

Re: 24->12 inverter wiring

Posted: Tue Jul 30, 2013 9:46 pm
by TechMOGogy
Hmmm more to it than I thought as well
I thought it was simple 24v in plus a ground and then you have 12v out plus a ground

Re: 24->12 inverter wiring

Posted: Tue Jul 30, 2013 9:58 pm
by krick3tt
Inverter is usually changing AC to DC...I think you mean converter to change 24 to 12, yes?

Re: 24->12 inverter wiring

Posted: Wed Jul 31, 2013 12:13 am
by Jimm391730
Hmmm more to it than I thought as well. I thought it was simple 24v in plus a ground and then you have 12v out plus a ground
That is exactly what is shown in figure 2. Don't be confused by the alternator and individual batteries that are shown, just notice that the converter has a single ground, 24V input, and 12V output (the 12V ground is shared with the 24V ground in this case).

Re: 24->12 inverter wiring

Posted: Wed Jul 31, 2013 7:18 am
by stark311
krick3tt wrote:Inverter is usually changing AC to DC...I think you mean converter to change 24 to 12, yes?
Exactly.

Re: 24->12 inverter wiring

Posted: Wed Jul 31, 2013 10:24 am
by audiocontr
Would recommend against those instructions! Ground to the chassis, NOT the battery.

Re: 24->12 inverter wiring

Posted: Wed Jul 31, 2013 12:13 pm
by edzz
audiocontr wrote:Would recommend against those instructions! Ground to the chassis, NOT the battery.
Agree these instructions do not take the Pinzgauers ground interrupt switch / system. This system is also usually defeated (potentially a bad thing) with most winch installations on a Pinzgauer. :shock:

Re: 24->12 inverter wiring

Posted: Wed Jul 31, 2013 12:22 pm
by Jimm391730
Figure 2 IS correct for Pinzgauers.

Re: 24->12 inverter wiring

Posted: Wed Jul 31, 2013 12:46 pm
by TechMOGogy
who to believe??
:mrgreen:

Re: 24->12 inverter wiring

Posted: Wed Jul 31, 2013 3:12 pm
by Jimm391730
who to believe??
We're all saying the same thing:
...Ground to the chassis, NOT the battery.
Shown in Figure 2. And note that the CAUTION warning (which we do NOT want to apply) does have an exception for figure 2. But for our trucks, it is generally considered best to NOT use the wiring as shown in figures 1, 3, or 4 (with a few rare exceptions, depending on the converter and what you are trying to do with it).

The biggest problem can arise with figures 1 and 4, with the battery negative disconnect switch open -- connecting 24V loads with the switch open will reverse the polarity of the 12V output, often frying the 12V devices... it's not easy to describe why this happens through text, just know that there are a few Pinz owners who have found out the hard way (fortunately, I'm not one of them!). This won't happen if the converter is grounded to chassis and not directly to the battery negative.

Re: 24->12 inverter wiring

Posted: Wed Jul 31, 2013 3:25 pm
by pcolette
I have 2 of the SurePower units that they made for John Deere construction equipment and am pleased with them. I mounted the units on the bulkhead behind the driver's seat and (as Jim M. said) connected the ground on the converter to the chassis ground side of the battery cutoff switch, not to the battery negative terminal. I also installed an illuminated red rocker switch in the 24V lead to the converter so I can be sure it is off.

Re: 24->12 inverter wiring

Posted: Thu Aug 01, 2013 7:49 am
by berger
pcolette wrote:I have 2 of the SurePower units that they made for John Deere construction equipment and am pleased with them. I mounted the units on the bulkhead behind the driver's seat and (as Jim M. said) connected the ground on the converter to the chassis ground side of the battery cutoff switch, not to the battery negative terminal. I also installed an illuminated red rocker switch in the 24V lead to the converter so I can be sure it is off.
One on eBay right now...

http://www.ebay.com/itm/John-Deere-AT14 ... 27d5ac0fad

Image

Re: 24->12 inverter wiring

Posted: Fri Aug 02, 2013 8:20 am
by Stekay
So now I'm wondering if the battery equalizer (not wired as converter) needs to be on the chassis side of the battery master switch "relay" as opposed to the chassis side of the battery master switch? I'm using the SurePower 52208.

Re: 24->12 inverter wiring

Posted: Fri Aug 02, 2013 8:39 am
by undysworld
Stekay,

Regarding EQUALIZERs:

To my knowledge, they battery equalizer goes at the batteries, not "inboard" of the master switch.

I had one, but occasionally still had one battery die. I was always under the impression that the equalizer merely drained off the higher charged battery to equalize it with the lower charged one. I eventually removed the equalizer from the truck.

But I had an idea you might consider. On my equalizer, the directions stated to connect the ground last to avoid damage to the equalizer. I thought to connect this ground via a 24 v relay which would be turned on by the master switch. That way, once the master switch is "on", then the ground for the equalizer would be made via the relay thus equalizing the batteries only when the truck is powered up. The equalizer would not be active when the master switch is off, thus no residual drain on either battery.

TechMOGogy,

I place my faith in Jimm391730's electrical knowledge over that of most of us.