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@SurfLung do you have a manual for that starter? I think I found the one you used on amazon.
https://www.amazon.com/Big-Horn-188...N77PXKZ7XCX&psc=1&refRID=N6HZTVEQFN77PXKZ7XCX

To get the pressure switch to work, you have to interrupt voltage to the coil itself. The key is making sure it's on a signal line, vs a power line, i..e nothing that carries any real current. It's going to have to interrupt one of the following lines. 96 to A, R/1 to 95, or the wire that goes to B. Without a better drawing or having one, I can't really tell you much else, but it's going to be in one of those wires which will open the circuit for the coil and drop the magnet back out. If you have a toggle switch laying around, I would start with that since it will do the same thing. Wire it between 96 and A first, start it up with the switch closed, and see what happens when you cut that circuit. It should function the same as the 20a breaker

61le2sPzviL._AC_SL1000_.jpg
 
Hi Tbone,
- Yes that's the one. The drawing is not great but it is better than most or no drawing at all... Which is what I was running into with the old starter. There's no manual or any documentation in the package. However there is another tiny diagram stuck to the inside of the cover. Slightly different.
- Thanks for the suggestions for the pressure switch. My first guess was the jumper between 13 and L3. But AntiqueDiver pointed out that it would leave me with one hot wire when the switch opened. His first suggestion was the same as yours: A to 96.
- Then I got to looking and saw the jumper between B and 14... Thought I had it there. But "B" is either not there or hidden between the top and bottom.
- Wouldn't R1 to 95 leave me with a hot wire again?
- Good idea to test it with a toggle switch... I WILL try A to 96 and test it with a toggle. Stay tuned...
 
@SurfLung so the way these things work is basically like an automatic light switch. In a normal light switch, you have a + wire that is switched and the bulb is always connected straight to the - side.
This "starter" is technically a contactor. In industry, these are used to control BIG loads remotely. i.e. you may have a normal light switch, but it is controller a big f*ckoff contactor. We have them where what is literally a normal light switch is tied to a 500hp motor at 600vac. It's a pretty slick concept that uses an electromagnet to "pull in" the switch.
In the case above, the contactor is powered by a 120vac circuit that is taken off of a transformer, but depending on the specific contactor, the coil could be a 12v coil, 5v USB powered coil, etc. based on the size. This is very similar to the relays used in your car for the horn, lights, starter etc. so you have very small current for signal inside the cabin, and the real current for the device stays more local. It allows the switches to be smaller, and offers a huge safety benefit. Anyway, in this case, the coil is actually powered by R1/L1 which is why it is tapped off of there. That's perfectly fine for the pressure switch because it isn't carry much current, only as much current as the coil itself will draw which is pretty negligible in a switch this small. R1-95 is the same circuit as 96-A, it's just that the switch will be before or after the "off" switch. Doesn't really matter in the grand scheme of things, it will be whichever one is more convenient. As long as that circuit is broken, the contactor SHOULD disengage. The reason to test with a toggle switch is you can grab one for $4 at any auto parts store, vs $100+ for a pressure switch and for testing purposes, it will do the same thing.
 
The Toggle Switch (pressure switch simulator) Idea Worked!
- With the toggle switch "ON" the "Normally Open" green START switch turns on the compressor. With the toggle switch "OFF" the START switch can't turn on the compressor because the circuit is still open due to the toggle switch being in the OFF or Open position. I connected the toggle switch in place of the A to 96 wire just as you and AntiqueDiver suggested. Here's the modified drawing Bill sent me.
stop%20start%20diagram.jpg


In the red lettering: Pressure switches have three wires coming off of them. Use a specific two wires to have the switch be Normally Open (NO) and use the other combination of two to have it be Normally Closed (NC). For this set up to work, the Normally Closed NC configuration is needed. This Tornado 3000 switch has the 3rd wire clipped short to dedicate it to NC status.
 
No, I simply pushed the starter switch with the toggle set to "On". And then pushed it with the toggle set to "OFF". Flicking the toggle with the machine running means holding onto the toggle with the current flowing and I figured to keep my hands away from possible shock. I see what you mean though. The coil will hold the magnetic switch closed when the "Start" switch is in the open position. I need to flick toggle to OFF while running to be sure it will interrupt the coil connection.

I've got the plumbing disassembled right now so I won't be turning on the compressor until I close that all up again. But stay tuned... :)
 
@SurfLung there's only signal current going through the switch, not full motor current, so just be careful but that's the test you really need to validate so it cuts off when it's supposed to. It should based on the diagram, but always safer to check before you put an expensive cutoff switch in the circuit
 
Filters and Pressure Switch
- As mentioned before, This Tornado Kidde has an automatic moisture drain. When the compressor is turned off, an "oil safety" opens and allows the liquid in the moisture condenser to drain back out the way it went in. I'm hoping to be able to use this system so I took it apart for inspection.
Filters01.jpg

- I found this inside had what looks like aquarium rocks about 2 inches deep and open air above that. I got the rocks out and cleaned it up with Dawn detergent. And, it looks clean and no corrosion on the inside. But the bottom elbow was partially clogged. I managed to unclog it but am wondering how likely it is to re-clog. The rocks are in there for condensation surface area I assume. I think this is usueable but I don't want to be taking it apart all the time to unclog that bottom elbow. I wonder how long they'd been running this thing with the clog?
- The filter is another story. The ends are held in by a steel ring in a groove.
Filters02.jpg

I had to tap the top inward with a wood mallet in order to get at the steel ring. Once I got the top off, I found the tube nearly full of carbon but with about 1/3 of the bottom filled with moisture absorbent. I vacuumed out all of the filter media and found it completely corroded.
Filters03.jpg

- So, the moisture condenser apparently didn't remove enough moisture. And the filter media didn't absorb enough moisture. OR, the previous users didn't bother to service this thing very often. Obviously, there are some very good reasons why they don't do things like this anymore. For now, I've decided I'll set this up to use the filter array from my RIX compressor.
- The next interesting thing is the pressure switch. Here's a photo:
Filters04.jpg
 
Clean up/Close up the Wiring...
- Here's the magnetic starter switch with the wiring all neatened up. There's not much room in the box so I kept the wires as short as possible and crimped on connector ends. I've left room for the pressure switch to be wired in as soon as I'm ready.
Switch01.jpg

Switch02.jpg
 
Testing the Pressure Switch and Over Pressure Valve.
- I hooked up a scuba tank to pressure gauge and the pressure switch. Turned on the air and watched the needle as the pressure rose. right at 2500 psi, the pressure switch will engage and turn off the compressor. This switch is "Normally Closed" (NC). So, when the pressure reaches its target, the switch opens, which turns off the compressor. For this test, I connected a voltmeter to the wires coming out of the pressure switch. And when the switch actuated, the voltmeter needle dropped. So, this test confirms the switch works and that it is set for 2500 PSI.
Filters04.jpg

- Next, I hooked up the OPV (Overpressure Valve) to a scuba tank in much the same way. I turned on the air and watched the needle climb. And sure enough, at 2800 psi, the OPV began to release pressure. So, this test confirms that the OPV works and that it is set for 2500 psi.
Tornado08.jpg

- So, the original set up for the Tornado Kidde 3000 was to fill the fire house tanks up to 2500 psi and then shut off. And if it failed to shut off, there would be a back-up OPV to release pressure beyond 2800 psi. I think that since I'll be filling vintage steel tanks, I probably won't fill anything over 2500 psi either (2500 psi is 10% over on a 2250 Scuba tank). I will leave these set the way they are and incorporate them into my final plumbing.
 
https://www.shearwater.com/products/swift/

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