securing the electrical harness
securing the electrical harness
(OP)
Hi,
What would be the best way to secure an electrical harness on high vibration components. I have tried using tie-straps and P-clips and everything seems to fail as the braid on the harness gets cut into and is cutting the insulation on the wires after some time.
Thanks
Nick
What would be the best way to secure an electrical harness on high vibration components. I have tried using tie-straps and P-clips and everything seems to fail as the braid on the harness gets cut into and is cutting the insulation on the wires after some time.
Thanks
Nick





RE: securing the electrical harness
Mike Halloran
Pembroke Pines, FL, USA
RE: securing the electrical harness
RE: securing the electrical harness
Second - Were the P-clips plastic coated or metal only? I have a lot of good experience with plastic coated P-clips holding slit-loom covered harnesses on forklifts. Non-suspended & solid rubber tires = lots of vibration. My theory is that the slip-loom still allows the harness to move around so you generally don't put a lot of wear or stress on any single conductor.
Third - Other possibilities: closer P-clip spacing, harness "tray", some type of clip braided into the harness (support from within instead of trying to carry. Also good for assy.)
BTW - We banned tie-straps where ever possible due to the manufacturing variabilites (routing, harness tension, tie-strap tension, etc.).
IceStationZebra
RE: securing the electrical harness
Some form of conduit, like spiral of nylon or PVC hose or split tube as already suggested.
Regards
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RE: securing the electrical harness
Typically I use Adel clamps that I get from aircraft surplus (their pretty pricey retail)...usually about two bucks a pound in various sizes.
The tie wrap situation is also curable with aircraft suitable quality (you won't find them at Wal*Mart, sorry) and the proper installation tool. If you don't have the tool, be sure not to make the cable tie too tight.
One trick I use on trailers is to use fuel or vacuum hose as a conduit held in place with properly sized Adel clamps...not suitable for engine compartments, though. I still tape my harnesses, even though it's very difficult.
Rod
RE: securing the electrical harness
If the potential products are not labelled, there are 2 simple tests.
Firstly, throw them in water, nylon always sinks, polypropylene mostly floats unless it has some fillers, which is unlikely to be the case with cable ties.
Another test is to burn a small piece and smell the smoke. Nylon has a distinctive strong smell like burnt feathers or a bit like celery. Polypropylene is fairly bland smelling like candle wax. If you do it once with known samples, you will never forget.
Polypropylene will fail at a little over 100 deg C while nylon will withstand over 200 deg C. Natural nylon will outlast polypropylene about 4 or 5 times in sunlight. Black colour will help both re UV light.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: securing the electrical harness
That was a valuable information.
Coming to my situation I am using straps (Nylon) at some location and I had seen that the harness basically moves and the strap is cutting into the harness.
I have also use P-clips, but because of different sizes of bundles I have to size them correctly and use almost 60 to 70 different clips. Does anyone face the same problem, and if so how did you resolve it.
Thanks
Nick
RE: securing the electrical harness
Nick, I still prefer the Adel clamps as they do not cut into the wire bundle or harness like the P clamps often do.
As to 60+ clamps---try a conduit of some sort. The many different sizes??? Sorry, that's just part of the game.
Rod
RE: securing the electrical harness
We use nylon cable ties on boats all the time and they are subject to movement and vibration 24/7 sometimes for weeks at a time and I haven't seen this problem unless the harness isn't secured properly.
There has to be movement before there can be abrasion so is it possible you are not tightening them enough or are not using enough of them. We usually secure every 12 inches.
I pad out the smaller diameter bundles with hose so I don't have to carry small clips. It's easy to slice off an inch of hose and tuck it under the cable-tie, protects and looks good too.
RE: securing the electrical harness
RE: securing the electrical harness
They really bounce around with gut wrenching force. Also engines are solid mounted so there is high frequency low amplitude vibrations from the motor and low frequency high amplitude vibration from wave impact.
I always wrap with loom tape and tie tightly to frame members.
Do you wrap with loom tape.
If so, is it possible to reinforce the loom with steel wire also taped into it.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: securing the electrical harness
regards, Steve
RE: securing the electrical harness