Breakaway cable

CharlieRN

Despite being only a couple of years old and never used in winter, my breakaway safety cable has deteriorated and come apart in several spots. I'm sure the plastic pin is OK, and so I could simply cut off the old cable and use some wire rope to replace it. Etrailer has a replacement with a coiled design that looks like it may be a better idea however:

A quick search of the forum seems to indicate that the pin on the etrailer replacement will fit into the OEM switch. Can anyone confirm that's correct? There also seems to be some disagreement as to which length to use. A quick measurement suggests that the four foot replacement may be a bit too small, but that means the six foot option is likely too long. I'm inclined to go with the 6' since I can shorten it if needed. Suggestions?

bjn2

Yes, the Fastway breakaway pin fits the box on our Tab 320. You want the cable to disconnect before your safety chains/cables are at full extension. I bought the long one but it's way too long to disconnect properly. The short one is plenty long for our 2023 model. The coiled cords aren't that easy to shorten unless you have the means to swage the cut ends. Ideally, the safety cable would connect to the vehicle someplace other than on the receiver (in case it's the receiver that fails). I may eventually add a mount to the TV bumper or body.  

AnOldUR

bjn2 said:

... You want the cable to disconnect before your safety chains/cables are at full extension ...

I have not seen any legal regulations on this and there are arguments for both sides. My personal opinion is to have the chains be the first thing to engage in the event of the trailer becoming uncoupled. The 7-way cable and the breakaway cable should be long enough so that that they will not pull out unless the chains fail and there's been complete separation. If the chains are still connected, I feel I have a much better chance of safely pulling over using a combination of the existing brake settings that activate the TV brakes and trailer brakes proportionally and also activating the trailer brakes using the manual lever as needed. Once the breakaway pin pulls out and the trailer brakes lock up you will lose that control. I my opinion the breakaway brakes should only engage once the chains have failed. This will prevent a runaway trailer causing collateral damage. YMMV

pthomas745

This "how long should the break away brake cable be" is one of the few trailer towing situations where "experts" give you a choice on how long the cable should be. See page 60 of the Purdue Extension "Keep The Trailer Connected" brochure.

https://www.extension.purdue.edu/extmedia/ppp/ppp-92.pdf

This same question has come up before, and the Purdue document examined.  There is a mountain of interesting information about chains, bolts, etc.

This thread quotes the brochure, and discusses the two options.

https://tab-rv.vanillacommunity.com/discussion/7840/emergency-release-brake

bjn2

I'm basing my recommendation using (A) the length of the OEM uncoiled cable, which is shorter than the extended chains and (B) Fastway's product recommendation which reads, "If the distance between your brake switch to the connection point on your tow vehicle is less than 3', purchase the 4' ZIP Breakaway Cable. If the distance is more than 3', we recommend the 6' ZIP Breakaway Cable."

Mickerly

I bought the 6ft cable. It works fine. The plastic coating prevents corrosion and wear. When not in use is stores nicely in the trailer rail.

On the length argument, I side with the NTSB where they explain the emergency brake system is to stop the trailer if or when it becomes disconnected from the tow vehicle, preventing damage to other people's property. This would be after the chains are broken or disconnected. Note: the NTSB has only findings or opinions with no regulatory authority.

The argument for length are several sides and no defensible correct answer. This is probably why Purdue University takes both sides. Part of the problem is privately owned/recreational trailers under 10,000lb are not covered by DOT regulation. Commercial trailers require air brakes which engage when the trailer is disconnected. Most states have guidance for recreational trailers stating something like, "If trailer brakes are installed, an emergency system is required to apply the trailer brakes if it becomes disconnected from the tow vehicle." I chased this bunny before. No definitive correct answer; lots of "if, then" and "option of the owner" kinds of statements.

CharlieRN

Thanks to @bjn2 for confirming that the pin on the Fastway breakaway cable will work in the Esco switch. Thanks also to the other responders for opening my eyes on the subject of breakaway cable length; I had no idea it was a controversial issue!

On the subject of cable length, some may recall that I posted a while back in another thread about experiencing an unanticipated separation of my T@B from my TV. That incident did not result in the breakaway cable pulling out and engaging the trailer brakes, something that until now, I hadn't thought about. Let me also add that my safety chains are shortened, and are just long enough to not be fully stretched when turning/backing. 

As near as I can tell, the breakaway cable as supplied by nuCamp was 48" which leads me to conclude three things.

The first is that the four-foot breakaway OEM cable is sufficiently long, at least for a 320 BD (2021). The second is that since the electric brakes were not triggered during the disconnect incident, it would seem that nuCamp believes that the braking system should be engaged only when the trailer becomes fully disconnected from the TV. Third, if statement #2 is correct, you can safely use either the 4' or the 6' Fastway cable, since it a coiled design. You would not want a six foot cable if you used wire rope because there would be too much excess.

Marceline

AnOldUR said:

bjn2 said:

... You want the cable to disconnect before your safety chains/cables are at full extension ...

I have not seen any legal regulations on this and there are arguments for both sides. My personal opinion is to have the chains be the first thing to engage in the event of the trailer becoming uncoupled. The 7-way cable and the breakaway cable should be long enough so that that they will not pull out unless the chains fail and there's been complete separation. If the chains are still connected, I feel I have a much better chance of safely pulling over using a combination of the existing brake settings that activate the TV brakes and trailer brakes proportionally and also activating the trailer brakes using the manual lever as needed. Once the breakaway pin pulls out and the trailer brakes lock up you will lose that control. I my opinion the breakaway brakes should only engage once the chains have failed. This will prevent a runaway trailer causing collateral damage. YMMV

I strongly agree with @AnOldUR

Link to my explanation.