Wiring the DC-to-DC Charger February 21, 2024, 07:03:17 pm Hello Again,I installed my DC-to-DC charger this morning, on the outside righthand wall of the under-fridge cabinet, just above the floor. That went fine, but I hit a bit of a snag when I went to wire the unit: the incoming wire from the contactor is 4 gauge, and the maximum wire size for my unit is 6 gauge - oops.The unit is a Victron Orion-Tr Smart 12 volt 30 amp DC to DC charger (Non Isolated).I'm not sure of a way around this problem - at least one that is safe and code-compliant.Question for Jor: you mentioned that you had installed a 30 amp charger in your rig. What brand/model did you get? I'll assume that you also had to deal with a 4 gauge input wire. Was your charger able to accept this wire size?Thanks,Tim
Re: Wiring the DC-to-DC Charger Reply #1 – February 21, 2024, 10:51:47 pm QuoteQuestion for Jor: you mentioned that you had installed a 30 amp charger in your rig. What brand/model did you get? I'll assume that you also had to deal with a 4 gauge input wire. Was your charger able to accept this wire size?I'm using a 60 amp Renogy but I have it set at 30 amps. The Renogy will accept thick wires.You could install an inline fuse to solve the problem. 4 gauge incoming from the contactor and 6 gauge to your charger. jor
Re: Wiring the DC-to-DC Charger Reply #2 – February 21, 2024, 11:31:51 pm Jor,An inline fuse is a great idea! Are there any that you would recommend?Thanks,Tim
Re: Wiring the DC-to-DC Charger Reply #3 – February 22, 2024, 01:57:47 am Tim; No you don't need to add anything! You have a #4 wire, and the piece of equipment can only handle up to #6, because of it can only handle 30A. For clarity: #4 is a larger wire than #6. You can cut a few strands off of the wire right where it connects at the connector until it will fit in your DC-DC charger. Not a code violation! Even in reverse it wouldn't be a problem. (the DC-DC wouldn't be able to provide it's maximum capability, but it isn't dangerous, and no codes apply!) In your house if you have a 20A socket capable of providing 20A, you can still plug in a pencil sharpener that takes 100 Milliamps. RonB
Re: Wiring the DC-to-DC Charger Reply #4 – February 22, 2024, 09:22:47 am QuoteAre there any that you would recommend?If you decide on a fuse or breaker rather than Ron's suggestion, any of these would do. Or you could use a little buss bar.joranlanl fusebreakerbuss barjor As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Re: Wiring the DC-to-DC Charger Reply #5 – February 22, 2024, 09:29:13 am "You can cut a few strands off of the wire right where it connects at the connector..."That's what I've had to do on occasion.I like Victron equipment, and I've used a lot of it over the years, but one thing I don't like is that their chargers, solar controllers and some other products have screw-clamp terminals that won't accept large wire. I really wish they'd use studs, so that I could use ring terminals--those I can get for any size wire, not just "up to" AWG 6. 1 Likes
Re: Wiring the DC-to-DC Charger Reply #6 – February 22, 2024, 10:16:22 am Andy - yes, I agree, I really like the Victron equipment, but this charger has been aggravating.Ron - yes, I've already done as you suggested - removed enough strands to get the 4 gauge into the unit. It seems to work, but now I'm trying to reset the unit so that it will power up. Apparently, I did not get the startup sequence right when I first hooked it up.I'll see if I can get it working correctly - if not I'll just return it ( I purchased it February 4), and perhaps look into the Renogy, which Jor says accepts larger input wires.Tim
Re: Wiring the DC-to-DC Charger Reply #7 – February 22, 2024, 01:25:24 pm Guys,Do I need a fuse between the contactor and the charger? Currently I just have a 60A fuse between the charger and the battery. I had forgotten about this, but I'd have to assume that it would be a good idea.Tim
Re: Wiring the DC-to-DC Charger Reply #8 – February 22, 2024, 04:17:03 pm There should be a fuse between the alternator/starting battery and the charger and another fuse in the wiring running from the charger to the coach battery.Not sure if that was what you wanted to know.Larry
Re: Wiring the DC-to-DC Charger Reply #9 – February 22, 2024, 04:57:21 pm Larry,Yes, that's what I wanted to know, thanks.I'll be adding a fuse between the alternator and the charger.Tim
Re: Wiring the DC-to-DC Charger Reply #10 – February 22, 2024, 06:29:32 pm Hi Tim, I have a 150A circuit breaker at the under hood terminus of the wire going to the DC/DC charger. At that end I have another 100A circuit breaker near the batteries. That wire goes straight into the Renogy 60A DC/DC charger. Although it is 'isolated' both ground wires go to the ground buss bar separately. The positive output of the charger goes to the battery buss bar. That is fed through the Battery 1, 2, 1+2 or neither 500A switch into the batteries. RonB 1 Likes
Re: Wiring the DC-to-DC Charger Reply #11 – February 23, 2024, 01:31:44 pm Hi Ron,I bought a 60 amp circuit breaker that I will install just upstream of the charger. I also have a 60 amp fuse at the busbar, downstream from the charger.Is 60 amps okay for the fuse and breaker? The charger is just 30 amps.Thanks,Tim
Re: Wiring the DC-to-DC Charger Reply #12 – February 23, 2024, 11:01:56 pm "Is 60 amps okay for the fuse and breaker? The charger is just 30 amps."That depends upon what cable you're using to connect them. Fuses and breakers are meant to protect the wire (e.g., from a short circuit), not the device. To determine the correct fuse, use an ampacity table. It's a little confusing at first glance, so here's a quick overview.For example, suppose you're using AWG 6 cable with two conductors in a jacket (e.g., this 6/2 cable). On the chart, you'll find the wire gauge on the left, then read across to find the cable's maximum safe amperage capacity. Because the wires are jacketed, you need to go to the second group of ratings--the first group is for single wires.The cable in this example is rated for 105° C maximum temperatures (most good quality cable is), but you won't be using it in an engine room, so you look for the 105° C column but not the "EngRm" section of that column. In this case, the ampacity is 84 amps, so you'd want to fuse for less than that to protect the wire.
Re: Wiring the DC-to-DC Charger Reply #13 – February 24, 2024, 04:01:57 pm Hi Tim, the #4 wire that LD supplied to charge your battery(s) is capable of much more current than your 30A DC/DC charger will ever take. If it were to develop an internal short, it should already have a limit built in to disconnect power. The #4 wire source can supply a very large amount of power. I believe your 2014 has the same solenoid (really a relay) that Kent had in his 2015, and is now my emergency start relay. Rated for a continuous 200A, momentary 600A inrush, it could be a fire hazard if the #4 wire was crushed (to ground) somewhere on it's way to your battery box. The 60A fuse or breaker (you don't need both) really won't help in that situation. Place a resettable breaker at the 'solenoid' on the firewall to protect that wire on it's way to the battery box. 30A isn't much in the world of high current 12VDC wiring. Amazon.com: 60AMP Circuit Breaker with Manual Reset,12V-48V DC Waterproof... Another way to think of this: if you had a water hose that might burst, having a shut off valve at the end won't help. It needs a valve at the entrance of water to the hose, so that it were to burst, it could be shut off at the source (alternator or chassis battery). RonB 2 Likes As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Re: Wiring the DC-to-DC Charger Reply #14 – February 24, 2024, 08:40:57 pm "if you had a water hose that might burst, having a shut off valve at the end won't help. It needs a valve at the entrance of water to the hose, so that it were to burst, it could be shut off at the source"That's a great analogy, Ron! 2 Likes
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Topic: Wiring the DC-to-DC Charger (Read 388 times)
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