propane pressure and O2 concentrator problem

[CorriDawn]

Ok, I have two stupid questions.

#1 I have 2 oxygen concentrators running. I have a Bobcat. what should my propane pressure be set at?

#2 One of my oxygen concentrators will run for awhile, half an hour maybe, then the alarm will go off. If I leave it (trying to finish the bead) the alarm will go off for about 4 -5 minutes, then stop beeping. it will work for another 20 minutes to half an hour then the same thing happens. what is wrong????

[MikeAurelius]

#1. Even though you have two concentrators, you still have the same pressure (at about 92% pure oxygen) - about 8 PSI. I am a firm believer in the 2 to 1 ratio of oxygen to propane for soft glass, so I would set the propane to about 4 PSI. If you are using borosilicate glass, go 3 to 1 oxygen to propane.

#2. Might be a couple of different things. Concentrators aren't always designed to work together, and it might be detecting a higher pressure (or some back pressure) in the system and alarming off because of that. To see if that is the problem, disconnect the troublesome concentrator from the oxygen line and let it run by itself. If it does not alarm, the problem is back pressure from the other concentrator, and it might need to be serviced.

If it does alarm, the concentrator itself might be alarming because the oxygen concentration is dropping - which is an indicator that the beds might need to be repoured.

These are educated guesses only, and I would get in touch with Paulette from Suncoast - she can probably tell you exactly what is going on.

[BillBrach]

Corri,

5-7 PSI is what I set my propane regulator for. It really doesn't make much difference, as long as you don't set the regulator so high that the size of the flame is difficult to control with the red knob on the torch. Some regulators don't regulate very well at 5, so if higher gives better regulation, up to no more than 10, then use a higher setting.

And, I would think that one concentrator would be fine for a Bobcat, unless you are doing boro.

If you will reply back on what model concentrator you have that is acting up, I may have some suggestions. If it does need to have the beds overhauled, I can handle that if you can pull them out and send them to me.

Bill

[CorriDawn]

I am going to try to shade my tank and hope that helps.

The concentrator says HealthDyne Technologies Alliance model H-505

[alexm]

I use a Lynx with two oxygen concentrators without a problem. The trick is to leave the oxygen valve on your torch all the way open and adjust the flame by varying the amount of propane.

If this is what you are doing and the oxycon is still alarming, then I would take it in for service.

[BillBrach]

Ah ha !!

There is a similar problem like this with the HealthDyne BX-5000 model. I wonder if yours could have the same problem.

This will require taking the unit apart. Inside on a BX-5000, there is a pressure switch that causes the unit to switch beds. If this doesn't happen within a certain time interval, it will alarm. This would also explain why it quits after a while. What happens is as the pressure from the compressor builds, a diaphram device pushes a microswitch, and this contact closure causes the control board to switch the beds. As the compressor wears, it doesn't "quite" have enough pressure to trip the switch.

If I had the unit in my hands I could instantly point to it and tell you how to adjust it.

What I will do tomorrow, is take a picture of the pressure switch in a Healthdyne unit I'm currently servicing, and post it. If your unit has the same pressure switch, I will then tell you how to adjust it.

Bill

[CorriDawn]

You are wonderful Bill!!! It is just so frustrating

[BillBrach]

Corri, now you gotta take your unit apart and see if you can find something that looks a little like the first picture. This is a closeup of the pressure switch.

The second picture is taken farther back, to give you a perspective of size, of the pressure switch.


http://img.photobucket.com/albums/v140/billbrach/closeup.jpg


http://img.photobucket.com/albums/v140/billbrach/long_view.jpg

[CorriDawn]

Ok, found it. now what?

36

37

[BillBrach]

Corri,

Sorry, I don't see anything in your picture that looks like the BX-5000 pressure switch.

In my first picture, below the silver tubular thing, is a square black 'microswitch" with two wires attached (pink connectors on either end are the electrical connections).

Are you saying you see something like this in your unit ??

PS - I just downloaded your picture and adjusted it. That device is the actual air solenoid that switches the two beds. The balck and red wires are going to the controller board.

If you DON'T see the pressure switch like my unit has, then your unit is probably different, and my fix won't work.

Bill

[CorriDawn]

Jason said he thought the first pic was it.

There is a knob on the top that says pull to adjust and has a plus and minus. don't know what that means or if I want to turn it which way I would turn it

[BillBrach]

I suspect that that is the output pressure regulator. The actual output pressure as a human ocygen device is probably important, but for torching it does make much difference.

Out of curiousity, if you ONLY run on this unit, does it do the same thing, meaning eventually alarming ??

Or, does it ONLY alarm when BOTH ox cons are connected ??

And, another question, is this a 5 LPM unit and how many LPM is it running at ??

[CorriDawn]

I have been running both since October and never had a problem. I haven't tried running just this one.

I think Jason should just buy me a new one

[BillBrach]

Where I was going is if this unit is running OVER 5 LPM (if it is a 5 LPM unit) or if it is running near ZERO, then either of these conditions will cause an alarm on perfectly good units.

I'd suspect in the Phoenix area, concentrators must be a "dime a dozen" with all the geriatrics that live there.

Tell Jason to be a good bitch assistant and go fetch another one :)

[CorriDawn]

Thanks. I am from the school of thought that if you throw money at the problem it will fix it. so I will call somewhere in the morning

[BillBrach]

I have a company that I buy parts from, that sells all over the US. I could contact them and see if they have a dealer in the Phoenix area to refer you to.

[CorriDawn]

And Jason is a good Bitch Assistant... he does what I ask. :D

[Jason]

Corri's H-505 appears to have the pressure switch mounted on the controller circuit board with a small hose running to it. In this pic:

64

It appears to work like this: Compressed air comes from the compressor thru hose A. It goes to B which splits it both up and over to each bed valve and also down through three small hoses. One of these goes nowhere (appears to be capped off with a removable cap), one goes to the solenoid device (D), and the third goes to the pressure sensor switch on the controller PCB:

65

The solenoid D has two small air hose outputs that appear to go to the two valves (C) on top of the beds apparently to control their direction (compressed air into the bed or air out of the bed out to the large white exhaust filter thing).

I turned it on about 20 mins ago (still opened up) with nothing attached to the output. The output is set at about 4.5 l/min (I believe this is a 5 l/min device) and the built-in oxygen sensor is indicating that the oxygen concentration is good. Right now I'm just waiting for it to fail and alarm to see what it is doing.

Both cooling fans seem to be spinning OK and the compressor sounds relatively normal.

So, what are the possibilities? Could the compressor be starting to die and not providing quite enough pressure? Could the beds be exhausted? I believe they were both repoured right before we got it, roughly 300 hours ago.

If the pressure sensor on the PCB is just not quite sensitive enough, how would I go about adjusting it? It looks like there are a few pots (variable resistors) on the PCB right under the sensor.. my guess is that one of those needs to be adjusted one way or the other. I wish I had the schematics for that board :) Google reveals absolutely nothing about this model.

As far as back pressure from hooking two concentrators together.. she's using a Y adapter from Suncoast that appears to have two one-way valves between each concentrator and the actual Y, so I don't think she would be getting positive pressure coming into the unit.

[Jason]

Could it just be heat related? These things are in a very hot garage and it was extra hot yesterday when she was using them.. and they've been recently moved between two cabinets so maybe they aren't getting as much ventilation as before. What effect would heat have? Would that cause the compressor to not be as effective? Or perhaps the compressor just overheated and shut off (it is labeled as being thermally protected). Corri, could you tell over the noise of the other concentrator and the alarm beeping if it got any quieter like the compressor was not running for that 10-15 mins?

[BillBrach]

DON'T turn any pots on the PCB. I'd suspect that the triangular black device on the PCB is a O2 sensor. See if you can get a closeup shot of it, or write down the #'s on it.

Yes, heat can be a problem, especially with the compressor. Running the unit out of the case should solve this, at least from a troubleshooting standpoint.

300 hours on the beds is NOTHING !! I'm running units that have several thousand hours on the bed, that have fine O2 output.

All of those plastic hoses that look brown look to me that they may be bad. The O2 discolors them over time, and hardens the plastic also. Are they stiffer than you think they should be and are any of them loose on any fittings ?? If they are loose, you can use a 4" plastic tie-wrap to tighten them up. You can also buy new tubing at Lowe's or Home Depot for cheap, but BEWARE, it is REAL EASY to break the plastic fittings the hoses are pushed on to, as the flowing O2 has made them brittle too. I usually cut the hoses off CAREFULLY, so as not to damage the fitting. If the hoses have any pliability left in the, the tie-wraps would be the best solution.

[bhtfld]

I also have a h-505 alarm is on all the time when it is on - will not silence - any ideas anybody?

[2CoolBeads]

Anyone ever solve this? I have the same concentrator and the alarm goes off after a bit of use. Also one of those hoses in the pic above after the splitter labeled B is not capped on mine and just lets out oxy - is it supposed to? Anyone?

[2CoolBeads]

I figure a picture would illustrate my ? better. I have circled the tube in question..it just hisses and blows - wondering if this is why I am getting alarms? It's a Heallthdye Alliance 505