Bauer Junior ii E1
My battle with getting my MrodAir Extreme doesn’t have a predictable, good outcome. Still waiting for a solution to its oil in air problem, but at least I now have another compressor to actually use. Thanks to my CFO (wife)!
Ordered a Bauer Jr II E (230 volt single phase) from Joe B. it arrived in a few days, on a pallet and well secured. Weight was somewhere around 150-160 pounds.
Top and sides of box and lift off in one piece. Made it easy for the two of us to lift it off the pallet. No lifting out of a tall box.
Fully uncrated.
Included accessories
Size comparison with the “bad” Airmax predecessor. Pretty comparable in size if you include the required water bucket. Build level isn’t even fair to compare. I couldn’t wait to fire the new Bauer up. I had already rewired the garage for a 4 prong 240 volt outlet. I anticipated swapping out the Bauer’s existing power cord with one that fits my outlet
What? No power cord. That is a surprise. Are no compressors plug and play? I guess I’m supposed to wire one into this junction box.
I found the motor’s wiring diagram and a bunch of wires inside the junction box. Called Joe B. and got some encouragement and general advice about going through one wire at time — process of elimination. After figuring out how the wires should go together, I realized there wasn’t any way to turn the compressor on or off. A call to Joe B. verified that’s the way they come. That meant also creating a motor control box. My anticipated three wire connecting project was now something bigger.
Motor wires connected
Put together a quick and dirty motor control box. I’ll change the internals to a contactor and add red & green push buttons later. Also, needs a thermal circuit breaker. This was enough to get things started.
Install filter cartridge and fill with oil. The compressor ships without oil in it. Took about half the supplied bottle to fill. You can’t see the level except via the dip stick. Fill in small amounts at a time because I didn’t know how much the compressor would actually need.
Finally, late at night, it was ready for initial run. 15 minutes without any load. Very little oil came out of bleed tube.
First pressurized run topped off Great White from 3800 to 4500 psi in six minutes. That’s with me slowing down the process by gradually adjusting the final stage valve incrementally up in pressure (counterclockwise).
Very pleased thus far with the compressor. Didn’t fumigate the garage like the Airmax. (All the spiders are dead post the Airmax fumigator). Delivered air from the Bauer is clean, cool and no longer a worry. The only downers were having to create a motor controller and figure out the motor wiring.
Wife is happy we did this and says this is a lesson on not being too cheap and ending up spending a lot more.
I have even had time to post in the Vulcan Bullpup section instead of working on a compressor.
[edited for grammar & show correct picture for wires]
All Replies
Nice job!
The compressor’s cylinders undergo “balanced” mechanical stress somewhere around 3,000 PSI. That is, at some pressure the mechanical load on the cylinders are most similar and the compressor will undergo the least stress. Since we are always filling to pressures above that point (as opposed to SCUBA) running “balanced” is not really something we can even strive to achieve. Air gunners simply will operate the compressor to a higher pressure 4,5000 – because we need that higher fill pressure.
So yes, having the compressor filling to a higher pressure is more mechanical strain. We largely offset that with our puny, total air volume requirements. We aren’t filling two, three, or four big empty cylinders/day. We’re typically just topping off a tank. Our run times are super short compared that what the compressor would see servicing a diver. I’m not too worried about the extra 60 seconds of higher pressure run due to setting my PMV to 3,000 rather than 1,800 when topping off a tank. It’s practically nothing in terms of real wear and the initial air that comes through the system has used a little bit less chemical absorber capacity.
Now, if I am filling from near empty, this effect is more pronounced. Rather than initially filling with the water separator and drier at 1800 psi efficiency, it’s going to be working at 3,000 PSI efficiency.
If we start with 14.7 PSI atmospheric and squeeze to 1800 PSI, the water separator can potentially wring water down to 14.7/1800 or 0.8% of original
With the PMV at 3000 PSI I’m forcing it to be 14.7/3000 or 0.5% of original water. That’s nearly twice the water separation efficiency while the tank is below 1800 PSI.
Again, many thanks for your great work and insight!
So, to be sure I understand correctly:
If the norm is refilling from 3,000-4,500 psi., one should increase the PMV to better balance the compressor.
By watching the whip gauge, one can see when the PMV opens by looking for a rapid (relative) psi rise and the set point for the PMV is at the top of this spike?
Joe or Guy: Any negative effects from raising the PMV to 3,000 psi?
Since my Bushbuck .45 fills (at high power) to around 4,200 psi, I often fill 3,200>4,500, so am concerned about the imbalance issue.
Thanks again!
And having a reliable, working compressor is wonderful. :biggrinn:
Did my bi-weekly Great White tank top-off (4000 to 4500 psi) today.
Effortless and without drama. No fuss or muss. It’s just nice. Entire sequence took under 10 minutes
1. Check oil level
2. Plug into AC power
3. Turn on compressor and purge fill line, separator, and filter tower.
4. Attach tank, let pressurize until PMV opens. Open tank valve when near tank pressure.
5. Fill tank with occasional bleed of water. I vent it more frequently than need, probably.
6. Close valves, bleed off tank valve
7. Bleed moisture from separator and drying tower – leaving system still pressurized.
8. Drain about 1 tsp of pretty clean water from waste water trap.
9. Unplug from AC
It’s really relaxing not having to deal with cooling water or messy drainage on the floor or in the air. Just plug and play.
After the costly Mrodair Extreme disaster, I had a choice of going down to a Shoebox or moving up to a dive compressor.
A dive compressor was totally worth it.
BTW, wear ear plugs. Even a Bauer Jr is 90 dB at your ears when you are operating the bleed valves.
That’s a commute for when I get my hypersonic vehicle back from the garage.
I looks like my Junior is starting to hold pressure after shut down better. Bled out the water after topping a tank and that left it at 4,000 PSI.
36 hours later it was holding 2,000 PSI –
3 days: 1200 PSI
5 days: 1150 PSI
8 days: 1100 PSI
11 days: 1000 PSI
17 days: 900 PSI
Much better than when it was brand new and leaking down to zero in 24 hours. This change in sealing ability really should be in the user manual.
It does look like it is staring to bed in its valves after a “whopping” 0.6 hour of total run time.
I’ll keep an eye on it over the next days, but this is promising.
I think I might need to hire you. What do you think about commuting to Southern California each day for work?
After the Neptuno read, I went back and more carefully assessed the PMV’s setting on my compressor. It was set just a tad below 2,000 PSI.
Checking the setting is easy with my gauge directly reading the pressure line & my amp panel meter showing the motor power draw. I can read the pressure even if my fill valve is closed. If yours is arranged with fill valve before the gauge, you need to open the fill valve, close the whip bleed valve and dead head the output. JB’s special Foster connector automatically dead heads. In my whip arrangement, I simply keep the fill valve shut and won’t ever get a false zero due to forgetting to open the fill valve.
When you first power up the compressor, the main stage water separator bleed should be open to avoid a high initial load at motor start up. The other two bleeds (on the P0 filter unit) don’t matter as much. Those can be closed at startup.
As pressure builds, no air gets past the PMV until it reaches the PMV’s set pressure. Your pressure gauge reads zero until then. A nice thing about my amp meter is I can watch the amperage draw climb as pressure rises. On my unit, the PMV is about to to open when current draw reaches 9.5 amps. When current draw gets there, it’s time to pay close attention to the pressure gauge. The power meter also gives me an additional way to monitor the compressor. I’ll also be able to watch the compressor for changes in draw over time and look for performance changes that might indicate need for maintenance.
Any ways, back to checking the PMV setting….
The gauge pressure on the fill whip will begin to rise at a moderate rate just as the PMV opens. Then it will climb very rapidly up to the PMV set pressure. Then the rate of climb will slow back down. What you are looking for is the pressure that it rapidly shoots up to. That is the PMV’s current set pressure.
The PMV is readily adjusted with a lens spanner wrench after you loosen the jam nut and set screw.
Make adjustments only with pressure in system bled back to ZERO and compressor OFF. Do not adjust while pressurized or running.
If you adjust the PMV while there is a pressure across the valve, or with the cooling effect of a pressure drop across the valve, the valve stem may grab and tear its seal.
Clockwise –> higher opening pressure.
Turn the adjustment a little at a time and retest the setting. Once you get to your desired setting, tighten the set screw and jam nut.
I had to turn mine almost 1/2 turn clockwise to change it from 1900 to 3000 PSI.
PMV, once set, shouldn’t need readjusting, but should be monitored to ensure it remains at correct pressure to let the water separator remove most of the water. Otherwise, the dryer cartridge has to do all the work, and that has limited capacity before saturation.
Going to a higher PMV setting was reasonable given that I only use the upper end of the pressure output. As delivered, my PMV was set too low even for SCUBA usage. Bauer recommends a value 60% of working pressure. A higher setting helps the final water separator wring out more water before the air reaches the filter cartridge. The filter won’t have to absorb as much water vapor.
The compressor won’t be unduly loaded by the higher PMV setting because my intended usage is at 3500 to 4500 PSI all the time during tank top ups, I may as well get drier air and longer filter life. The top up time is under five minutes anyway. Add the several minutes of startup and pre-bleed to remove water before hooking up the tank and I’m struggling to even reach ten minutes run time.
After today’s rainy day PMV adjust and tank top off session from 3500 to 4500 psi, the amount of waste water was around 10 ml. That was an amount easily absorbed by two paper towels when I drained my waste water catcher. Unlike the foul, heat cracked oil scent of waste water from my Mrodair Airmax Extreme, the Bauer Jr’s waste water is nearly odorless. The Bauer is clearly not consuming or dieseling tons of oil in the compressor. Also, I’m no longer breathing oil vapor in my garage. THIS is the way things should work.
Some links to interesting reads about care and feeding of compressors. Both contain nuggets useful to those contemplating a compressor.
http://www.michaelmcfadyenscuba.info/viewpage.php?page_id=16
http://www.neptunoworld.com/articles/compressors.html
The calculations regarding volumes, flows and time constants are a bit wonky, but overall good stuff to consider. Of particular interest were the parts about the pressure maintaining valve (aka priority valve) and how it improves water removal and balances the compressor. Unfortunate, that we often top off above 4,000 PSI range. I guess our small volume requirements/year make it easier on the compressor. The divers use lot more air.
Maybe I need to rethink tank refilling strategy. The usual paradigm is to fill the tank to max because going to the dive shop or Sports Chalet means a cost/fill & time spent. You want the most value/fill, hence full 4,500 is desirable for maximum usable air. That doesn’t quite fit the situation when you have a compressor. There isn’t as much need to get max fills/tank because you can top off the tank any time. More wear and tear of the compressor at higher pressures comes into the equation. If the tank is used at home, like mine, then I may as well fill a bit lower and reduce stress on the compressor. Now, if the tank is going into the field, you want max pressure, but for home use, it might be smarter to keep the fill pressure under 4,000. You still get quite a few gun fills and the compressor lets you top off conveniently.
Also…
The MrodAir turns its oil black in just an hour of run time.
Joe, I’ll start using more abrupt bleeding. Once more I’m probably being too gentle on the equipment.
Guy, When I bleed mine, I give it a quick BLAST from each of the 3 knobs. I do this to force the water out, and allow everthing to seat again.
I only bleed enough to remove water, I don’t bleed down to any particualr pressure. It ends up wherever it ends up (usually a couple thousand PSI)
The intermediate separator bleeds out far more water than the final separator and filter. I’d say maybe 3 – 5 times more.
BTW changed the schematic again. Now the 1 amp fuse also protects against wiring failure in the hour and power meters. Should have thought of that earlier, but at least it is was just a 10 minute rewire to new configuration.
I’ve been making things since I was 10. One of my proudest moments was rebuilding the front end of a TV within 8 hours after a lightning strike vaporized components of the RF front end. Picture, when it was back, was completely purple because the strike had also magnetized the chassis. Degaussed and all was well. Had to fix that TV fast because there was some show I wanted to watch the next day. That was when I was maybe 15, before the days of videotape. Add decades of doing all sorts of projects and you’d be doing this stuff too.
Tried something new regarding the air leak post shutdown. Rather than gently bleeding the intermediate separator post shutdown, I bled it off quickly. I could hear the final stage valve “sing” and then seal during the fast bleed down. That might seat the pressure valve with more force than before. We’ll see if that makes a difference.
Nice work on your motor control box and thanks for sharing all your helpful information, I might upgrade mine also, I also like the screen in the water collector, when you bleed the compressor does more come out of the intermediate separator or the filter?
What is your back ground if I may ask, because I could not have come close to what you have done here and with the Airmax, I commend you with all your time, patience and hard work here.
Happy it is helpful to you.
A couple minor changes after a trip to Home Depot.
A new, inline 1 amp fuse now protects the contactor coil and on/off buttons. Schematic has been revised to reflect this addition. It’s not a likely point of failure, but fuses are in case the unlikely happens. Worth the couple bucks.
Also, changed the foam at the top of my waste water collector to some VERY tightly rolled aluminum screen. The foam had a tendency to pop out if venting was too fast. The aluminum screening is not going anywhere and still presents a large surface area to coalesce vapor.
A plastic cap from a sprain paint can conveniently deflects vented air downward. Otherwise, it comes up at your face.
Thanks a bunch for your detailed posts. Very helpful.
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Guy you sure make it look so easy, just connect this and that and your done. Me just a simple man and opted for yanking the cord to start the darn thing. 😛
Marko