Testing an Electric Blanket

Do you have to test simulating incontinence ?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

If you have the slightest doubt as to its safety, dispose of it. Faulty electric blankets are not only potentially lethal because of the shock hazard- they are a very real fire risk as well.

I speak from experience.

Dave

On Sat, 22 Jul 2006 14:57:53 -0400, n cook wrote (in article ):

My wife has Multiple Sclerosis and it's no joke to either of us.

On Sat, 22 Jul 2006 15:40:38 -0400, Dave D wrote (in article ):

Thanks for the "heads up". I have read that the new ones are "safe". Can you comment?

Just a "comment", if, repeat if, you have ANY reservations on using something that includes "speed of light" possible fatal media, discard it. BTW, what happened to the hot water rubber bottle? One of the _best_ replacements I met was a "dashhund" who liked to sleep on human bent legs under blanket. Wonderful invention!.

Good luck.

Stanislaw Slack user from Uladulla.

Well, realistically they have to be pretty safe to meet modern regulations. A new one is likely to be a negligible risk. However, I just don't like the idea of mains electricity flowing through a blanket, and when they have some wear on them it will inevitably affect the insulation and hence their safety.

Personally, I can't recommend the use of electric blankets at all, but then maybe I'm just over cautious ;-) I would certainly never use one designed to be left on when you're in bed.

Dave

Plug it in, turn it on, turn out the lights, watch for sheet lightening........... d:->))

There's really nothing to test, either it works or it doesn't. If it's physically damaged, don't use it, but if it looks ok and it heats up, it's fine.

Ah it's the greatest thing in cold winters, the wires are heavily insulated, they're inside a blanket, and over a sheet. Cloth doesn't conduct, what are the chances of actually getting electrocuted?

Yeah and my house could fall down in an earthquake in my sleep, or I could trip and break my neck on my way to the bathroom at night, things happen.

It IS scientificaly/statisticaly(chose one) proven that most people die in bed, ergo sleep like a donkey, standing.

Have fun

Stanislaw Slack user from Ulladulla.

James: About 5 years ago I had a blanket that woke up both my wife and I with what appeared to be dim lightning flashes in the room.... it turned out that a short circuit or loose connection developed inside the blanket. When we turned on the lights to investigate there was a burnt spot on the blanket and we could hear a snapping sound. Even thought the blanket was well past it's warranty and we had no receipt, the service center we sent it to REPLACED with a new one, NO CHARGE...... so from now on we are quite alert as to possible problems.... and yes, we still use an electric blanket on our bed. electricitym . .

Dont forget the fire risk ;)

Slim but possible, but that's perhaps not their primary danger.

You would perhaps have a different attitude if you'd been in a house where an electric blanket burst into flames and set the bed alight. Half an hour later and my parents would have been under it and asleep. Lucky I was in the house at the time- they didn't smell the burning at all but I did and we managed to put it out quickly.

Dave

James-

I think the chances are slim, but the OP had a special problem. Considering the risks, one might decide to avoid use of an electric blanket in some circumstances, unless there was an additional plastic sheet between the user and the blanket. (The alternative of non-electric blankets may be an undesireable choice due to the additional weight required.)

As far as testing is concerned, perhaps a blanket could be soaked in a saline solution in a conductive tub. Electrical leakage could be measured between the tub and the blanket wiring. For a meaningful test, full voltage (current limited) would be applied between the wiring and the tub. For a safety factor, higher voltage might be used.

Passing such a test doesn't guarantee that leakage won't develop later from normal wear and tear, so you're back where you started!

Fred

On Tue, 25 Jul 2006 12:25:30 -0400, snipped-for-privacy@aol.com (Fred McKenzie) put finger to keyboard and composed:

I'd suggest dispensing with the electric blanket and pre-warming the bed with a portable fan heater.

- Franc Zabkar

Even more fires are started by clothing draped over fires which this is equivalent to - highly dangerous. Restricted air supply leads to excessive heat build up. The traditional hinged double copper "frying pans" on a broom handle with hot coals from the fire, sounds much safer. On a related matter the local fire service had a black museum. One of its seized exhibits was a home-made bed warmer. Someone started with a soldiers steel helmet, nailed some wooden dowels on the inside, nails in the other ends to wrap the element wire from an electric fire around.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

On Wed, 26 Jul 2006 02:35:52 -0400, Franc Zabkar wrote (in article ):

I appreciate all those who have given constructive suggestions. For the record, my wife has Multiple Sclerosis one symptom of which is poor blood circulation. She is always "cold" even in the summer. More blankets, which only keep body heat in, don't help. What is needed is a heat source other than her body. Hence the electric blanket. She still complains it isn't warm enough and I have no idea how to test if it is working properly merely from a heating perspective. It feels warm but not hot. I assume, without taking the thing apart, that there are a bunch of resistive elements wired in parallel. Thus some could be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to work, but do not get very warm. On the other hand, I don't recall how warm they are supposed to get. I am sure they are regulated so that you don't inadvertently burn yourself from a high setting. I would have just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety tests" for electric blankets, so there must be some protocol. I was just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I assume the main risks are shock and fire. My presumption was that the UL certification covered those and the ones I have carry UL certification.

I suppose the best thing to do is to just buy a new one. And yet, without understanding the failure modes of the old ones, there still remains in my mind a safety concern.

non-electric

One thing you might consider is a heavy duty "space-blanket" sold in outdoor pursuit shops, not the thin emergency types as used at the end of marathons but the mesh reinforced ones. It, of course, does not pre-heat the bed but does reflect your own body heat back to you during the night which is probably the main concern.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

non-electric

My recommendation would be a mixture of low tec and high tec and no electric blanket. A conventional hot water bottle to pre-heat the bed and an underblanket of reinforced mylar space blanket.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on