Help! Anybody have a extra PRS1 series 50 humidifier?

Hmmm, hard to say what the jumped what looks to be a ground. Perhaps a detection mechanism for heated tube option or something.

I would say black is probably your ground, red is your hot wire for the heating element and blue may be a thermocouple for detecting heat.

It'd be interesting to see the heating element's electrical behavior on different settings.

In any case, I still think the better way to do what we need would be more akin to a fish tank style water heater.... something that's submerged in the tank and mounted in reliable but non permanent manner.

If you have a multimeter handy I'd test the resistance between black and red, betcha there's something like ~20ohms resistance. If I'm right about the thermocouple there should be millivolts DC, that change as heat is added or removed from the plate.

Man, I'll have to experiment with this.

As for why your humidifier doesn't work. Who knows.

Shawn TW wrote:

Please let me know ... I'll be home again in a week and a half ... Until then I'll have to manage!

I was wondering if you found a solution by now? Did you find a humidifier or fix the one you had? Hope so.

Regards, Oak

Mines still broke ... I'm getting one from TigerLily mailed to my house ... Should be waiting for me hopefully when I get home this weekend!

I looked my 60 series humidifier, I have a 6 pin connector VS your 4 (you can see extra wires for the heated hose). I'll get the meter out of the garage and see if I can get it pinned out.

Depending on what part of the humidifier that the machine's complaining about, you might just throw a large ceramic resistor into the tank wired to the heating element as a backup.

So, I don't think there's a coil in the heater. Red and Blue appear to be shorted/going to the same place (<3 ohms); I was not able to measure any millivolts DC with the pad heated between any pins (so I don't think there's a thermocouple as originally thought). There was no change in resistance with the pad warmed between R/B.

I was getting about 9 kohm at room temperature between Black and Red/Blue (again, they appear to go to the same place?) When I put the humidifier into preheat mode for a few seconds without the tank I started getting 5 kohm, which says some kind of resistor VS a plain wire coil heating element.

What's it all mean? Not sure, I only do electronics as a passing interest. But, I do think it means people could dunk an appropriately rated resistor into the tank, wire it up and have a functioning humidifier if replacing the entire enclosure is cost or time prohibitive. However, due to the efficiency with which it'd be transferring heat.... it won't get as hot as it won't build up a lot of heat = more resistance. Ceramic coil resistors might be better when used directly in the tank.

The wires to the heating pad feel very stiff for the gauge and are reluctant to bend, they feel like they might be solid core vs stranded, which may account for some failures.

I think the heating pad is completely 'dumb'; it has no way of sensing or controlling heat output. The main unit must control electrical output entirely and doesn't seek any feedback from the pad (which, I guess makes sense since these things will run dry and get hot enough to smell bad VS shutting off).

For safety reasons, the heat disk must have a thermal overload sensor. Some types of
sensor (like the one in my hairdryer) automatically reset when they cool down. Others,
(like the one in my rice cooker) cannot be reset and must be replaced.

jdm2857 wrote:For safety reasons, the heat disk must have a thermal overload sensor. Some types of
sensor (like the one in my hairdryer) automatically reset when they cool down. Others,
(like the one in my rice cooker) cannot be reset and must be replaced.

Maybe, that may be why there are two wires that appear to be going to the same place. Maybe something melts causing an open circuit on one of the 3 wires,

I just tested with my meter set at 200 ohm ... it read .03 between the black, and the jumper, and 3.2 between the red and black, the blue is not connected to any of the other pins.

I found this on both the one I took pictures of, and the new replacement that I got!

I took my PR system one humidifier apart after the useless visit by the tech-support guy told me what we both knew..the heating element is dead..... Then I figured out that if I could find the $5 part on the Internet, I could fix it myself or even make it since I am also an Electronic Engineer...should be a cinch right? Wrong!! There are no service manuals, parts lists, or any trace of supplier anywhere---all I found was the conversation of several OSA chat rooms and support groups. You good people are the closet thing to a solution on the net...

But most interestingly....the photos from fizzled and Shawn TW are just like the unit I have and the part numbers in the pictures MATCH EXACTLY....now to find the supplier. I'm going to cross query this against every parts manufacturer's Db I can access. PR does have service manuals and training courses behind firewalls that want either money, or course registration and money in order to get to the information. Maybe we could find an old ex-student who would scan the parts list and share it. The manufactured part doesn't have any manufacturer's ID on it, and it is probably dirt cheap. My continuity checks found that the dark black and grey-black wires are looped across two of the 4 pins. On my element, the red wire had continuity check to the black wires and the blue wire looked like an open circuit. I'm guessing the blue wire is the wire that carries current for all settings and the red wire carries current when the higher humidity settings are used. the looped black wire splits the return current to 2 pins going back to the control unit. It's probably that simple, because it is a really cheap device....too bad PR wants $150 for a whole new unit. Anyone wonder why health care is so high? We just have to search those part numbers and find a supply source---I'm tempted to use an electron microscope to determine what kind of heating elements are buried inside that shiny black epoxy...