DC/DC charger location

[JimB]

Have read a number of discussions on the location and wiring for the DC to DC charger. This is a picture that Escape sent me that shows an install in a 21C. I can not find a wiring diagram that shows this equipment. Wondering what the input positive is and what the two output positives are (as in where do they go? Thanks

[MVA]

I am not sure how ETI wired it, but the input should be from your charging lead on your 7 pin. The output should be to your battery. I have the non-BT version which I suspect has the same mounting requirements; vertically and to a non combustible surface. Appears to not be installed correctly. Check Victron manual.

The 2 positive output wires are confusing. I would disconnect and trace with a meter.

2 cents

[rubicon327]

It looks like they are using the output positive as a node but the screw terminals on the Victron Orion are designed for one 6AWG wire max. That connection should be scrutinized. The jumper on the negatives seems odd but should be just fine. ETI could also have used the cheaper non-isolated version of the same unit with only one negative terminal. Depending on how the trailer is wired you can lose your electric brake function if you isolate the ground. This happened to me when I installed my own Victron Orion 12/12- 18 Isolated as part of my lithium battery upgrade.

[Centex]

The 'jumped' negatives is interesting to me, especially given that the pictured charger is the "isolated" version offered by Victron (they also offer non-isolated versions).

Note this has no bearing on 'isolation' of the vehicle battery from the trailer battery but relates to galvanic isolation which may or may not be of import in this case (I think an "isolated" charger is not necessary for our trailer installations but would be interested in other's thoughts).

I believe that 'jumping' the negatives (grounds) effectively negates the galvanic isolation characteristics of the unit, begging the question: "Why pay extra for an "isolated" version of the DC/DC converter"?

Resources of potential interest:

Victron DC to DC Orion Chargers. Isolated or Non Isolated ? Which is right ?

An article on Isolated vs non-isolated power converters
_____________

Unrelated to the above, it's beyond me why ETI seems to struggle with the clear installation orientation instructions from Victron :

• Mount vertically on a non-flammable surface, with the power
terminals facing downwards. Observe a minimum clearance of
10 cm under and above the product for optimal cooling.

Yes, that means that in these confined spaces they may need to make the wiring connections before mounting the unit; what's so difficult about that?

[John in Santa Cruz]

Note there's multiple versions of the Orion-Tr, there's a DC-DC 'power supply', and there's a DC-DC Charger. AFAIK, the chargers are all 'smart' and have bluetooth, the 'power supply' doesn't.

[JimB]

I hadn’t understood the issues of the power jack and the breakaway switch - important stuff. I wonder if that is why the second positive wire is there in the Escape installation? Thanks all for your time.

[Brian B-P]

Since the tow vehicle and trailer both have the battery negative connected to their respective frames, and those frames are electrically connected, there is no purpose to an isolated converter in this application. It seems harmless to me, but also pointless, to buy an isolated unit and defeat the isolation, whether it is defeated by a jumper at the terminals or connections elsewhere in the trailer.

[John in Santa Cruz]

the isolated Orion-Tr Smart chargers come in 12/12-18, 12/12-30, and various 24V models, so only the two 12/12 models are suitable for our use case here (12V in, 12V out, 18 or 30 amps out)

the only 12/12V non-isolated smartcharger is 30A. IMHO, 30A output is too much for these applications as that is going to draw as much as 45 amps from the voltage-reduced-by-wiring-loss input in order to provide LFP 14V at 30A, and few tow vehiles will be happy with that kind of draw.

the Orion-Tr 'converters' aren't suitable for this use case at all, they are power supplies, not battery chargers.

[Brian B-P]

Originally Posted by John in Santa Cruz

the Orion-Tr 'converters' aren't suitable for this use case at all, they are power supplies, not battery chargers.

The stock direct connection of the tow vehicle's circuit to the trailer's battery is also not a battery charger; a fixed-voltage converter set at a reasonable level (somewhere between 13.2 and 14.0 V?) would be more suitable than that direct connection.

[rubicon327]

Originally Posted by Brian B-P

Since the tow vehicle and trailer both have the battery negative connected to their respective frames, and those frames are electrically connected, there is no purpose to an isolated converter in this application. It seems harmless to me, but also pointless, to buy an isolated unit and defeat the isolation, whether it is defeated by a jumper at the terminals or connections elsewhere in the trailer.

Agreed. I bought an isolated unit unnecessarily when I did my lithium upgrade. Honestly I didn’t realize that I could have gotten away with the non-isolated version until after it was installed. Not turning back now but for others they should save the money and buy non-isolated.

[JimB]

This is the drawing that Samuel from Escape posted on TheEscapeForum as a verified drawing. I see what they did with the second positive wire in the output side (goes back to the trailer brakes terminal in the 7 pin junction box). This would seem to address the ability to keep power on for breakaway brakes?

[rubicon327]

Originally Posted by JimB

This is the drawing that Samuel from Escape posted on TheEscapeForum as a verified drawing. I see what they did with the second positive wire in the output side (goes back to the trailer brakes terminal in the 7 pin junction box). This would seem to address the ability to keep power on for breakaway brakes?

That’s great if ETI is finally starting to do some system level electrical drawings. As far as the positive wiring at the Victron it would still be better if that second conductor was landed on the battery side of the 50A fuse. This puts the one 12V+ conductor from tow vehicle under the screw terminal of the Victron and doesn’t put any fusing on the breakaway line which is arguably the proper design.

[Viajante]

I’m going to nitpick the wiring diagram a little even though it is good to have Escape provide a schematic.

I don’t think the diagram properly shows brake wiring. It shows all brake power running through the breakaway switch. Actually, there should be a solid blue line from the 7 pin junction to the trailer brakes without connecting to the breakaway switch. The red 10awg line from the charger should go to the breakaway switch, then a fuse, then to the 7pin junction brake terminal (blue).

Another nitpick is the labeling. The terminals labeled turn ind/brake should read turn ind/stop. Just to be clear that those wires activate the stop lights, not the brakes.

I know that this wasn’t meant to be a comprehensive diagram of the 12v system (e.g. it doesn’t show the power jack connection), but someone might use it to wire their brakes.

[JimB]

Thanks for the replies! So I had installed the charger as per the drawing from Escape. It didn’t work (no LEDs and not seen by Victron connect. As per the drawing I wired the 10 gauge red back from charger output to the 7th lug in the 7 pin junction box as shown in the drawing. It would seem this is an issue?

In any event when I follow this drawing I lose power to the 7 pin box and as previously stated the charger does not work. I took the charger back out and bench tested it by hooking up the input side to a battery - LEDs work and unit is seen by Victron Connect. So it seems it is not the unit…

Any other ideas as to how to test or remedy this? I read with interest the issues with this front of trailer location, but can accept that for now if I can get the unit working to at least protect my alternator.

[Viajante]

If you you wire the 10awg directly to the 7th lug as shown in the diagram you will have constant power to the brakes, as in the brakes will be on the max all the time. That’s why the 10awg goes to the breakaway switch first, so the emergency braking only comes on when the breakaway cable is pulled.

[Viajante]

https://www.escapeforum.org/forums/a...4&d=1612491891

If I copied this right it shows a better diagram of the brake wiring system. It shows how the brakes are connected to the 7th lug. And the 8awg wire also connected to the 7th lug is equivalent to the 10awg wire in the Escape diagram. You can see how it goes through the breakaway switch before connecting to the lug.

I think the diagram is thanks to tdf-Texas.

[JimB]

Glad you pointed that out! So if I terminate the 10 gauge at the break away switch I note that as in this picture the wires to/from the switch are small (16 gauge?). What would be the best way to wire the 10 gauge to this location? Given the small size of the existing wires to the break away would you use a 15 amp fuse?

[Viajante]

Personally, I would follow the breakaway switch wires back into the trailer and make the connection there. I guess the tdf diagram doesn't show a separate fuse for the switch. There is a 40 amp fuse at the battery. 15 amp would be too small.

For installation of the charger you can leave the 10awg wire disconnected for now and just hook up the main power leads. See if it works. Just connect to the breakaway switch before using the trailer.

I wish I could help more but my knowledge is about used up.

I would also check the fuses and the battery charge. It is possible you had the brakes on for quite awhile, but probably not if the charger want working. Please note that the wire from the battery to the 7pin junction does not go through the battery shutoff.

[JimB]

Thanks again for taking the time to help work through this. I have since looked closely at the 7 pin junction box. As pointed out the wiring diagram provided by tdf-Texas is more accurate. Since I bought my trailer used, I wanted to make sure no wiring changes had been made - no changes. So hopefully someone at Escape can tell me exactly where and how they terminate the 10 AWG positive wire from the DC to DC outlet side. I would think they would have contemplated this as part of their $420 lithium ready option. Cheers.

[rubicon327]

Originally Posted by JimB

Thanks for the replies! So I had installed the charger as per the drawing from Escape. It didn’t work (no LEDs and not seen by Victron connect. As per the drawing I wired the 10 gauge red back from charger output to the 7th lug in the 7 pin junction box as shown in the drawing. It would seem this is an issue?

In any event when I follow this drawing I lose power to the 7 pin box and as previously stated the charger does not work. I took the charger back out and bench tested it by hooking up the input side to a battery - LEDs work and unit is seen by Victron Connect. So it seems it is not the unit…

Any other ideas as to how to test or remedy this? I read with interest the issues with this front of trailer location, but can accept that for now if I can get the unit working to at least protect my alternator.

Dumb question but did you plug in your tow vehicle and turn on the engine to provide power to the Victron?