Repair insulation on electrical wire

[Tom Miller]

I have an expensive medical device that works perfectly and is in pristine condition, except the insulation on the power cord has cracked slightly just where it enters the machine (it was bent over too sharply once when packed for travel). The thick outer insulation is cracked about halfway around the cord to the extent that you can just barely see the covered wires inside the cable. The cable is permanently fixed to the machine (doesn't unplug at the machine end). It is round, and about the diameter and quality of a computer power cable.

I need a way to seal up this crack in a neat, workmanlike way so that it will not continue to fray, and so it doesn't look like an electrical hazard. But what to use? I now have a turn of plastic electrical tape over the break, but that won't do for the long term.

I simply don't dare open the device and shorten the wire. If I were to break the machine it's like tossing $800 down the toilet.

A little plastic tube about 1/2" long over the crack would be best, but I can't slide a typical heat-shrink tube over the area without cracking open the machine and removing the cable to slip on the tube

-- which I don't dare do.

There's no electrical danger from the crack, as the wires inside are still insulated from each other and it's a tiny crack. But if we have to take it to the hospital, as occasionally happens, I'm concerned that someone will balk at letting us plug it in because of the cracked wire. Hospitals are so rule-bound about patient medical devices that this is a real issue.

I've thought about liquid electrical tape, but not sure that it will be neat and tidy. And will it be thick enough to fill the crack? And will it hold? I want a finished look as well as a bond strong enough so it doesn't crack again easily.

Any ideas? TIA

[xrongor]

maybe cut the plug off, slip the heat shrink on that end without opening the machine, then put a new plug on?

randy

[Jeff Wisnia]

If it is a "power cord" it must have a plug on the far end, huh?

So....

Cut the plug off the end of the cord.

Slide a length of appropriate diameter black heat shrink tubing up the cord to cover the place where the outer sheath is cracked.

Shrink the tubing with a heat gun, or a carefully applied gas cigarette lighter flame if heat gun isn't available.

Attach a new plug on the other end of the cord.

QED

Jeff

[Bob K 207]

OP-

I get the feeling this is a medical device in a hospital?

Get one of the electricians to replace the entire cord properly or do it yourself.

this isn't brain surgery

btw what kind of device is it?

[Dave]

Is this worth your time? I think I would replace the whole cord, and it would probably be easier than you think. Be sure to use the proper gauge wire. However first you should factor in the cost to drive to the hardware store a couple of times and the fact that you can write off the cost of repair. Also remember the implications of a mistake. An electrician may be cheap insurance, unless you are doing this as a kind of personal challenge. Then the rewards may be strangely worth the effort.

Dave

[Joseph Meehan]

I don't like the heat shrink idea. Chances are the whole cord is old and needs to be replaced to be safe. If you don't have the skills to replace the cord yourself have someone do it for you. Life is too short to be shortened or messed up by taking the easy way out.

[John Grabowski]

I suggest that you contact the manufactuer and ask them what they recommend. Other posters have given you some suggestions that for a power tool or lamp might be sufficient. When it comes to medical equipment that is used in a hospital and may come in contact with patients or staff the liability is tremendous. You will probably need to send it back to the manufacturer to get the cord replaced properly and relieve yourself of the liability. The manufacturer may even fix it for free.

If you were to repair the cord yourself and an accident occured, a bunch of lawyers would eat you for breakfast and your own insurance company may turn their back on you.

John Grabowski

[Stormin Mormon]

I'm with Bob on this one. A machine of that value is worth a couple bucks to have an electrician replace the cord.

[Tom Miller]

Well, I may have to have it done, but to have the cord replaced will cost me at least $125.00 -- and probably more -- for a very minor problem -- a 10 cent problem. If this problem were on a lamp, for example, or on one of my computers, I wouldn't even tape it up. Having medical equipment repaired by a durable medical equipment dealer is a real ripoff.

The device in question is a Continuous Positive Airway Pressure device

-- a pump that prevents collapse of the airway while sleeping. It's a prescription item in the USA. It's mine, for my personal use, not a device in a hospital.

The real problem is that if I have someone else fix it, I can kiss it goodbye for a week or more while they send it off to some repair place, which means that I can't sleep properly at night. I walk around all day like an oxygen-starved zombie until I get it back. And it affects my ability to drive, too. Yeah, there are ways around all this but they all cost money and are not real convenient.

There is no conceivable liability issue involved. The machine is 6 years old, so it is not ancient. There is nothing wrong with it otherwise. The crack came about when I packed it into a case and travelled around for two weeks with it banging against the inside of the case until the cord started to split right where it goes into the machine. I have used the machine for several years since it happened and it works fine. You can barely see the split even if you look carefully.

I have several chronic medical conditions which have occasionally taken me to the hospital overnight. Having the machine makes the night bearable; one less thing to worry about.

Once I spent the night in an emergency room waiting for a regular hospital bed so I could have a coronary stent implanted in an artery next day. They would not allow me to plug in the breathing device because it had not been approved by their electrician (who was home sleeping). As a result I had to stay up all night. This is not the way you want to prepare for a guy putting a steel mesh tube in your heart using a wire and a balloon!

I guess cutting the plug off the cord and slipping a heat shrink tube over it is the only way, but putting a new, non-molded plug on the cord opens yet another possible electrical issue for the hospital to object to. I just thought there might be a clean, neat way that would not involve this, but I guess not.

Thanks to all for the suggestions.

[Oscar_Lives]

Oh, hell. Quit making such a big deal over nothing.

Get a loaner CPAP from your DME and send in the old one to get repaired.

Better yet, get a new CPAP and keep the old one for a spare. Six years old means it probably has over 17,000 hours on it and it is probably worn out. You got your money's worth if it lasted 6 years. Besides, I'll bet you got your insurance company or Medicare to pay for 80% of the cost.

[Tom Miller]

It's not me making this into a big deal. I'm just asking for a simple electrical repair suggestion on a tiny problem.

My DME doesn't give loaners. In fact, my DME is such a money grubbing crook that I never deal with them any more. My insurance company doesn't pay for this device. The machine works fine. Why toss away $800-$1200?

[Oscar_Lives]

buy one from

for $400 instead of using the local crooked DME.

[willshak]

You might try a CA glue, like Krazy Glue. It will glue rubber and plastic. I once used CA to glue an air tube for a Badger compressor and it held for years.

[Joe Fabeitz]

[Dave]

An electician could replace a cord in an hour, and you could schedule it so that you have it repaired while you wait.

Dave

[Tom Miller]

I've bought from Joe and from other online sources (there are cheaper sources than Joe, in fact). But my machine isn't broken. I need a cosmetic repair to the power cord. Apparently there isn't one, so I'll just keep on using it as is or look elsewhere for a repair suggestion.

[Tom Miller]

[snip]

This is the right kind of idea, and thanks for trying to offer a solution. Unfortunately, it's a small crack that needs to be filled and sealed, not a break that could be glued back together. I think I may try "liquid electrical tape" first and if that doesn't work then try cutting off the plug and slipping on a heat seal tube. Can't hurt I guess. Thanks again.

[Chris Lewis]

According to Joe Fabeitz :

Of course.

BUT, taking an obviously "unofficially repaired" device into a hospital is just asking for trouble. These things will have "only repaired by qualified and certified technician" warnings ALL over them. Any problems with it whatsoever in a place choca-bloc with lawyers on call, and you're toast.

No "repair" described so far is invisible. Even cutting off the plug, sliding on some heat shrink tubing, and then putting on a new plug will be abundantly obvious it's not an official repair (because it won't be a molded-on plug).

A hospital is likely to refuse it if they see it first, and have a fit if they detect it later.

The guy is in between a rock and a hard place. The manufacturer _may_ charge something ridiculous to fix it. Anything the OP does without opening the case will be "obvious".

Frankly, I wouldn't trust any glue, and electrical tape wouldn't do much good in this situation.

In the OP's situation, I personally would open the thing and shorten the cord, as long as I could make sure I could do the repair invisibly (both inside and out, unit doesn't have anti-tamper indicators etc).

Here, tho, the hospital issue wouldn't arise, because they'd supply one as necessary, so I could leave a slightly more obviously butchered unit at home. I'm not so bad off that a few days without one will be a problem.

Fortunately, my CPAP doesn't have a hard-wired cord. It has a replaceable standard appliance cord (like a PC). Get cut? Dig through my odds-and-ends box for another complete cord, no "repair" required.

Unfortunately, I do have the same problem with a submersible sump pump. Given that the line HAS to be water proof, I'm going to have to do surgery on the unit and put a brand new cord on it to avoid problems with the cord cracking again.

I'm with Joe. Ask the manufacturer. A regular TV or appliance tech might well be able to fix it "legally" too. I should hope you could get it repaired for