Charging plus why two breakers?

I Am switching off the thread @ http://www.hilotrailerforum.com/f28/trailer-battery-not-charging-while-traveling-4705/index2.html and starting a new one.

I replaced breaker 1 (on outside of battery box) and that seemed to solve the issue of current from tv not getting to my house batteries for charging. Old breaker had corrosion on one post and intermittent continuity. But- obviously, wires run to breaker 1 then back to breaker 2(inside of the box) and from there wires disappear into the netherworld of wiring run. QUESTION: Why two breakers? I am generally confused by many things electrical and, now, more so. Insight welcome.

Rick

Seeing your pics, I suspect that the one in the box also governs other devices requiring the same amps. Just a guess......
Tree

Rick, I'm guessing here, but are they wired in parallel? If so, it's because each carries half the load in Amps instead of having a single higher Amperage rated circuit breaker.

A single one would be better, in my opinion, but the required size may not be available.

- Jack

One breaker feeds the lift motor and also the second breaker. The second breaker feeds the trailer circuits including the converter.

Here are wiring diagrams that show the layout: http://www.hilotrailerforum.com/f51/hi-lo-2306-primary-wiring-116/

Older trailers may vary on that, looking in a manual, which you can find in the Forum Library, and see what they show.

Well- if you notice, there is a red wire and a yellow wire and i think a black wire that run to breaker 1 on the
accessory" side-then that heavy black wire runs back into the box and attaches to breaker two (on 12 v post) . There are also other wires running off breaker two and onward. I guess I dont know if they are parallel without knowing what everything is- but as far as one breaker being connected to the other on the 12 volt post- then they are. They are both 30 amp. I've got the wiring diagram from the link that rich sent me for an 06- and mine is an 01- and it shows two breakers -but I'm really not very good at tracing the rest. Just was wondering if anyone else had dealt with these----its info that might come in handy. Splitting the amperage makes sense- as the highest replacement I remember seeing was 50 amp.

Rick

Well, I looked at the primary wiring diagram, and I think the system MAY have been designed by a grade school dropout.

The main purpose of the first breaker seems to be to prevent overload to the lift jack on the tongue and the charger on the converter. The supply to the hydraulic cylinder motor is not overload protected at all. It pulls power directly from the battery and the tow vehicle's charging circuit, which will easily overload that charging circuit if the trailer battery is low. The other straight through connection is from the trailer battery to the breakaway safety brake application (which seems fine to me).

Then, the "protected supply" (limited to 30 Amps) is directed to the second breaker, and, is limited again (why?) to 30 Amps before being delivered to the refrigerator (which has its own 30 Amp fuse) and to the Master Switch. From the Master Switch, the Converter is supplied and the potential current is also reduced to 15 Amps before being delivered to the trailer top lift switch.

So, we have not one, not two, but THREE limits on current to the refrigerator that are identical, when all that is needed is one of them. And, we have two identical 30 Amp limits to the Master Switch and Converter, again, one would do the job. This is not "redundant" protection, it's simply additional "valves" in the lines that can fail. If any one of these malfunction, the supplied components stop working.

I'm describing a situation here that is equivalent to putting three, or two on/off valves, one after the other, in a water supply line. Why?

So, the breakers are NOT connected in parallel, but in series, which seems stupid to me.

- Jack

The breakers are in parallel in the diagram. I was looking at a couple of diagrams in the manuals and they don't even show power going to the second breaker. The draftsman must have run out of ink.

RichR said:

The breakers are in parallel in the diagram. I was looking at a couple of diagrams in the manuals and they don't even show power going to the second breaker. The draftsman must have run out of ink.

Click to expand...

Ah, Rich, I disagree. The ones in this diagram: http://www.hilotrailerforum.com/att...y-wiring-hi-lo-20wiring-rev.-201-20of-202.pdf are wired in series from the two possible power supplies (battery and tow vehicle).

Edit: I just removed a paragraph where I posted about a 30 Amp breaker in the converter. It's on the 120V supply line, and is certainly needed there.

- Jack

I think I see an error in the diagram. The #8 black wire going to the right terminal on CB-1 from what is shown as start should actually be on the left terminal, and the other black wire from there to the left terminal on CB-2 that way both breakers are being fed from the wire from the solenoid, thus the power goes through both breakers separately. The right terminal on CB-1 is hooked to the tow vehicle charge wire and the breakaway switch wire.

On CB-2 the left terminal is hooked only to the left terminal on CB-1, the right terminal feeds a blue wire to the fridge, a red wire to the master switch, and a black wire to the charger/converter.

I looked on the 2310H and that is how it is.

Can I get agreement on that? Thanks!

Sounds like Hi Lo owners may want to check their units to ensure there wired correctly.
Me do
Tree

This is a photo I took a few minutes ago.

I think you can see the wires I described.

I'll get back to you in a bit, Rich. Going down to check my trailer. But, from your photograph, it looks like you're probably right.

- Jack

OK, took me longer than I thought, but I decided to check for presence of mice. None in the trailer, so my mouseproofing seems to have been a success!

My wiring is ALMOST the same as yours Rich, except that the Blue (refrigerator line) is connected to the right hand terminal on the left CB (#1) on the same post as the black/orange (breakaway) and the other black wire which I think may be the tow vehicle charging input - it goes up into the trailer tow vehicle cord. The other (copper) post on #1 contains the +12V battery input (from the lift motor solenoid), the wire to the tongue jack motor and the jumper to the copper terminal of CB #2. The steel post on #2 has the red (Master Switch) wire and the black converter charger wire.

So, the CBs are not really hooked in series OR in parallel either! They get their input from a common supply (connected by the jumper), and then individually send power (in my case) to the breakaway switch and refrigerator (CB #1) and the battery charger and Master Switch (CB #2). Each of those sides is protected with its own, dedicated 30A breaker, which makes sense, because the whole system is rated at 30A.

In my trailer, and this is just a guess, it appears the tow vehicle charging current goes through CB #1 in a reverse direction, so that it charges the battery by way of the line from the lift motor solenoid, which is in turn connected directly to the +12V post on the battery.

So, in my trailer, the tongue jack motor and trailer top lift solenoid are unprotected and everything else is limited to 30A through only one of two identical CBs.

This makes a whole lot more sense than that incorrect diagram!

- Jack

Well- I guess I don't feel that stupid for asking, then. I'm wondering why they put one of mine on the outside exposed to weather and the other inside. The outside one I replaced had a manual reset. Makes me think somebody thought I would want to be able to reset that one without raising top to access the battery box. I also notice a wire lying in the box with a 15 amp fuse. I wonder what that one is. My power jack must have been installed later and I notice it is wired direct to the battery with a 30 amp inline fuse. Maybe cb 1 was meant to connect to the jack and they assumed you would need to access that even when top was down----but I assume that is what the manual crank is for. At any rate, thanks for shedding some light on all this, you guys. glad I asked.

Jack

You say your jack and lift solenoid are unprotected but mention that both those are connected to the cbs. That confuses me. My assumption is that if they are connected to the breakers then the breakers should offer protection.Not so?

hilltool said:

Jack

You say your jack and lift solenoid are unprotected but mention that both those are connected to the cbs. That confuses me. My assumption is that if they are connected to the breakers then the breakers should offer protection.Not so?

Click to expand...

They are connected on the hot side of the CB, but the tongue jack has an inline fuse. I think HiLo did some strange things over the years.

Jack,

I don't know why they did what they did. It must have been who was working on any particular day.

To clarify Rick's reply a bit - the tongue jack and lifting solenoid are connected to the INPUT side of CB #1 (the copper post). This is just a simple way to deliver power to both of them by connecting them directly to the +12V battery feed. The CB connection is just a "binding post" for the three wires. The only thing that CB protects are the items connected to the opposite (steel) post. Power has to go THROUGH the breaker to get to it. And, the breaker acts as an emergency shutoff for that route if the current flow is too large.

I did not know about the inline fuse on the tongue jack line, but it makes sense. I did not see it when I was down looking at my trailer and it's not on the wiring diagram.

Rich, I have to agree with you about things being done according to who was at work on a given day. Personally, I think the way my CBs are wired makes more sense than yours, since it looks like (to me) that it distributes the possible current flows more evenly. The breakaway switch is a low Amp device, so I think the refrigerator belongs on CB #1 with it.

I didn't have a camera when I was down there - I'll try to take a picture of my CB connections tomorrow.

- Jack

Jack, My hitch jack has a 30amp inline fuse. Without pulling it apart it must be a glass fuse. I can't see the fuse for the fridge but I assume it's inline somewhere, if not, it would be good for it to go through the breaker.

RichR said:

Jack, My hitch jack has a 30amp inline fuse. Without pulling it apart it must be a glass fuse. I can't see the fuse for the fridge but I assume it's inline somewhere, if not, it would be good for it to go through the breaker.

Click to expand...

It DOES, in my case Rich. If the refrigerator is running off the trailer battery (tow vehicle disconnected) the refrigerator is connected on the downstream side of the CB, so that will limit the current to it.

But, things are more complicated if the tow vehicle is connected and charging the trailer battery (and helping to power the refrigerator). The battery charging function seems to go through the CB in reverse, so it's protected there, but the TV charging line is connected directly to the refrigerator line. So, as I see it, the 30A fuse in my truck's charging circuit offers overload protection if there is no inline fuse in the blue refrigerator line.

Either way, as I see it, there is protection. The battery charging has double protection through the tow vehicle fuse and the trailer CB, and the refrigerator has one or two fuses protecting its supply.

- Jack