Uh oh, did i just mention reverse polarity ~ Camping

Hi, i have a resmed S9 and want to go camping in Europe. Some camping websites say that after buying a Euro Hook Up adapter the polarity may be reversed on cantinental sites but this should not effect modern equipment. Anyone know if a reversed polarity would affect the Res Med? Heard so much talk of converters inverters my head is spinning.

My husband says: "Look at the power supply block (brick) for the Resmed and if the input power supply voltage is in the range of 190 to 260 volts (can be a little lower or higher), at 50 or 60 cycles (Hz), that power supply will have no trouble at all." All you need is the prong adapter.

He's an electrical engineer. If you want to consult , PM me and I'll get you in touch with him.

I would be very careful about polarity. If the cpap machine doesn't have reverse voltage protection built in you may very well damage it if you hook it up to a power supply wired opposite what the machine is expecting. The power Jack on the cpap and/or the power brick are probably labeled with the polarity.

all this depends on whether we're talking 12-24vdc, or 220-240vac

if ac, there is no polarity, if dc... then that's a concern.

Thanks all, im still a little confused, but tat may be my default state!

I've contacted ResMed to see if the habe a definitive answer, the last thing I want to do is blow my S9 up half way around france!

Been checking on camping forums and they give differing opinions on polarity, just like on here. It seems it does happen, you can buy a tester, but nobody supplies a polarity reversing cable. It's a minefield.

Ill update uf resmed give me an answer x

PR is correct. Very few items are affected by polarity in alternating current.
For years, I have suspected it is a scam to drum up business for electricians.

As Pailrider says .... there is no polarity in AC current !

A campground can't have reverse polarity because they supply AC power at 110V or 220V 60 cycle here in USA ... and and in many other countries it is 220V 50 cycle.

The meaning of AC is "alternating current" .... so it is always reversing polarity, at 50 or 60 time a second

So the wide/narrow blades on electric plugs and outlets really are a scam?

http://www.doityourself.com/stry/how-do ... -plug-work

Polarized plugs work as a safety mechanism to prevent electrical shock if you touch an energized part of the appliance.

chunkyfrog wrote:So the wide/narrow blades on electric plugs and outlets really are a scam?

you know better that...

Yep, while in tech school, I was a drafter at Square-D. Guess what they made?

chunkyfrog wrote:Yep, while in tech school, I was a drafter at Square-D. Guess what they made?

round Fs?

Ok, it had become clear what the "polarity" issue the OP raised actually is.

It's not about electrical polarity, as in DC systems, but rather about which pin on a normal consumer grade AC power outlet is the "active" one. Most domestic AC single phase power outlets anywhere in the world have one pin which is at the full mains voltage with respect to "ground", and a second pin which is nominally at a reticulated ground potential (often referred to as "neutral"). If there is a third pin, it will be a local safety "ground".

For "double insulated" devices (such as most xPAPs) it doesn't matter which way around the active/neutral connection is made at the power outlet, but for "single insulated" devices it is quite important to make sure that the correct active/neutral connections are made so that any safety-ground connection is effective.

The point with European power outlets is that the most common ones (IEC Types C and F) do not have an explicit orientation with respect to plug insertion, so the active/neutral relationship depends entirely on which way you insert the plug (or plug adapter). This is undoubtably why only some non-European travellers are reporting " polarity reversal" on European power outlets .

However, in the case of xPAP devices it doesn't matter anyway as they are double insulated, so the OP has nothing to be concerned about