[Equipment] Portable generator to power S9

[OMyMyOHellYes]

Maybe a gas powered cpap machine LOL.

Please don't say "gas" and "cpap" in the same sentence. When I first started, I put the S8 on the floor by the head of the bed. Right next to where the Saint Bernard slept.

Nothing like pressurized dog flatulence piped directly into your nose.

OMM

[Ghost1958]

Maybe a gas powered cpap machine LOL.

Please don't say "gas" and "cpap" in the same sentence. When I first started, I put the S8 on the floor by the head of the bed. Right next to where the Saint Bernard slept.

Nothing like pressurized dog flatulence piped directly into your nose.

OMM

[o2meister]

Thanks for all the input! The generator is a Honda model. Haven't tried it yet........

[GeoffD]

Can you use a portable generator to power an S9? I called ResMed technical support and they told me that you could NOT. Not sure if they just wanted to sell me a battery!

The short answer is NO you can't, but it depends on the generator. If your generator has permanent magnets instead of field coils, its a good chance it will produce suitable power. However most generators produce a sort of modified sine wave which is not suitable and will cause heat to build up in the power transformer of the PAP machine's power supply.The transformer will burn out. Any device equipped with a power transformer requires a pure sine wave power source. The alternative as you've been advised is to use an accumulator (battery), which is probably best anyway.

The power bricks that come with the CPAP machines do not use transformers - they are switch mode power supplies - no transformer.

Switch mode is much more efficient than a transformer and allows the the wide voltage range of 115 - 240 - you can't do that with a transformer; you would have to move a switch to use different tappings on the transformer.

This captures it. A switching power supply uses diodes to shape the AC SIN wave to DC. You can feed a total garbage wave form into it and it will still function just fine. A surge suppressor certainly wouldn't hurt but it would take a heck of a voltage spike to blow up a switching power supply.

If I lived somewhere with lousy power, I'd likely install a UPS (uninterruptible power supply). If I had _REALLY_ bad power, I'd run the unit off a couple of gel cells (yacht batteries) with a 24v supply to charge the gel cells. That's how carrier grade telephone equipment is powered but it uses 4 gel cells and 48v instead of the 24v DC a ResMed S9 uses.

[surferdude2]

I dropped out of this thread long ago since a lot of it is struck me as much ado about nothing. JMHO of course.

GeoffD is spot on with his comments and I wouldn't hesitate to run my CPAP power supply from any old generator I chose. Frying a switching power supply by not inputting a pure sine wave A.C. input isn't something I worry about. Neither is how a non-sinusoidal input voltage would affect the well filtered D.C. output. Stick a scope on the output and you'll see a straight line.

The greater worry may be that the power supply or CPAP machine will die a natural death and you would be better off using that extra money you spent on a pure sine wave type ginny to buy spare units for that occasion.

<ducking>

[o2meister]

Thanks again to all giving input! I'm a Registered Respiratory Therapist with 40 yrs experience including being a Department Director of a hospital-based Sleep Disorders Center. That didn't make me an RPSGT (registered sleep tech) nor do I know much about electronics. That's why I appreciate everyone's input!!

[Evpraxia]

I did call later this evening and there are gen sets with built in sine wave whatevers that a Rrespronics machine can be run from but they are costlier than the regular generator an a UPS in line to smooth the flow.

Yes, also if you buy a generator with the more expensive option and it blows up you also loose the sine wave and power conditioning of the UPS which is why it has always made more sense to me to use a less expensive generator and a better ups.

Just as an example a major liquidator is selling a 3250 generator for $219 delivered with free shipping currently which is way way more than you need for two paps and even a few lights, and a quick search yielded me this CyberPower CP850PFCLCD 850VA PURE Sinewave Series UPS - 10 Outlets which is also way more than needed for $119 from a large computer seller, and your all done. I can't post any commercial links here but if you want to PM me I'd be happy to link you.

If the genny dies you can replace it with anything, and if the ups dies same story. Otherwise you get stuck with a higher end genny that must be replaced with another high end unit.

Since my hubby and I are planing to be motorhoming in the next yr to yr 1/2 having the ability to use our APAPs is critical to our planning. Good info; thanks.