Breakaway Switch

[Raz]

Originally Posted by Bob Miller

I agree.... someone thought that it had been suggested in my post #22, but I don't see that even mentioned.

If the breakaway switch is activated and the safety chains are still intact (having survived the sudden jolt of the trailer brakes being applied) then it is safe to assume the umbilical is still attached as well. In that case the tow vehicle will be powering the trailer brakes, at least in part. Perhaps that's where the confusion lies.

In regard to fuses: fuses protect wires and little else because they are very slow to react. If the maximum current is 10 amps then use a 10 amp fuse. There is no need for derating. Remember a fuse is simply a wire designed to get hot enough to melt when the designated current is exceeded.

I would not fuse a break away switch as I'd rather know about any defects before it's needed and checking the fuse every time I head out is not something I wish to add to my list. Raz

[Bob Miller]

I'm sorry, but I still don't see any reference to your statement. The words in italics just aren't there.


"Bob, in post #22, first paragraph, you said you believe in fusing everything including the breakaway to the trailer." But, if what I wrote was misunderstood, I will try to be more exacting in the future.

All that said, my bigger concern and, reason for fusing the line from the trailers battery to the breakaway switch, mostly revolves around the general practice of never having a hot line that isn't protected, not only against overloads, but against possible short circuits.


I have worked on an untold number of RV's repairing wire damage and short circuits. Causes range from wire insulation wearing through from physical contact with frame edges etc. and rubbing through the insulation, to rodent damage from mice that seem to love the flavor of insulation. In almost all cases the extent of the damage was a blown fuse and not a burned up wire loom an un-fused short could have caused.


As an example, I am aware of apparent mice damage to an unfused wire starting an under hood fire that led to a motorhome being totaled by the insurance company. The rodent damage happened while it was in winter storage and it wasn't discovered until spring when the batterys were reinstalled and the smoke started.

[Jared J]

Originally Posted by Bob Miller

BTW: Where was it even suggested to connect the break-away switch to the TV's battery? I missed that.....

I never said it was. I've seen more than a few trailers with breakaway switches and no trailer batteries, operating under the misguided belief the tow power will provide the emergency braking, and we have people on here that don't have trailer batteries.

Hence, my comment. A breakaway switch is useless without a trailer battery.

As for the rest, if safety chains are the proper length (NOT by twisting them), the umbilical should be longer than them, and in no harm of disconnecting if the chains hold.


Sent from my iPhone using Fiberglass RV

[Borden]

In Ontario the breakaway switch is only needed if you have brakes on your trailer; then it is a requirement.

[Borden]

Originally Posted by Jared J

I never said it was. I've seen more than a few trailers with breakaway switches and no trailer batteries, operating under the misguided belief the tow power will provide the emergency braking, and we have people on here that don't have trailer batteries.

Hence, my comment. A breakaway switch is useless without a trailer battery.

As for the rest, if safety chains are the proper length (NOT by twisting them), the umbilical should be longer than them, and in no harm of disconnecting if the chains hold.


Sent from my iPhone using Fiberglass RV

How correct you are no power then when disconnected and it can not work; also add that in Ontario the battery is required if you have electric brakes with a breakaway switch.

[Bob Miller]

A number of breakaway switch kits come with their own small battery system that can be charged by the tow vehicle. Hence, while the trailer may not have it's own battery, the brakes will still be powered in the event of a switch actuation.


A 750 lb pop-up trailer I rebuilt two years had such an arrangement until I added a in-coach battery system

[EcoHeliGuy]

Funny thing I installed a brake-away battery kit on my Boler with a battery.

Realized my mistake when the charge light was illuminated in the brake-away battery while the tow vehicle wasn't connected. Now I just have a brake-away switch 😄


Sent remotely

[beardrum]

I'll spare you the story of my utility trailer repeatedly smacking the back of my truck when the hitch bounced off the ball. The end result is that I have a Curt 52010 breakaway switch to mount on my Scamp 16. The 52010 has two blue electrical leads and the usual plastic plug with a steel cable.

On the Scamp, the 7-conductor TV connector wire bundle disappears into the trailer at the right front, along with positive and negative leads from the battery. At the floor of the closet inside there is a bulge in the rat fur that covers a knot of wire nuts (Scamp's version of a distribution panel), in which I would expect to find the blue wire from the wiring harness connected to the blue wire that eventually emerges from the trailer floor just aft of the left (driver-side) wheel, from whence it goes to both brake drums.

I hope that's clear.

My plan is to mount the 52010 alongside the tongue, run both wires into the closet thru the same hole as the harness and leads from the battery, and connect one blue wire to the blue brake wire, and one blue wire to the (black) battery positive lead.

Seem like a good plan?

I don't need to worry about ground, since the 52010 is just on the hot side of the brake activation line, right? Or should I be sure there is a ground between the switch body and the tongue? (Hate to scratch away the paint on the tongue.)

Scamp seems to use wire nuts for the 12 volt connections. Is there a better way? Crimp-on connectors?


As always, thanks for any comments or suggestions,

Chuck

[Bob Miller]

Sounds good, but I would sped some time getting rid of any wire nuts, both on 12 VDC wires, and any you find outside of a terminal box on 120VAC wires.
You will need to get what's called a "Pressure Crimper" (not one of those pliers looking cheapies) and some good quality splices from an electronics shop. Cheap terminals/splices often have poor quality metal in them and loose their grip after a period of time. That's personal experience speaking here.....
Good Luck

[Terry G]

I agree with Bob the wire nuts aren't a good idea for a trailer or anything that moves and bounces up and down. After some bad experiences with crimp connectors, I learned to make all the connections on my Casita with solder and shrink wrap tubing. It's a bit more effort, but awfully secure.

[Carol H]

Originally Posted by Borden

In Ontario the breakaway switch is only needed if you have brakes on your trailer; then it is a requirement.

And in Ontario if the trailer weights more than 3000lbs loaded brakes are a requirement as well.